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Extension > Mark Seeley's WeatherTalk > 2017

Friday, September 22, 2017

A Flush of September Warmth and High Dew Points

A Flush of September Warmth and High Dew Points:


The trend toward above normal temperatures this month, which began on the 10th, continues in a big way through this weekend. Most observers now report September mean temperatures that are 2 to 4 degrees F warmer than normal, but have yet to see real extremes. This will change for Friday through Sunday as several areas of the state will see daytime highs soar into the 80s and 90s F, with nighttime lows in the 60s and 70s F. As a result, it is likely that some new daily temperature records will be set in terms of both warm daytime highs and warm nighttime lows. So far the highest temperature measured this month was 93 degrees F on the 14th at Browns Valley (Traverse County). This is likely to be surpassed.

According to the Minnesota State Climatology Office it is especially unusual to see a series of nighttime low temperatures in the 70s F so late in the month of September. In fact for the Twin Cities climate record consecutive nightly lows in the 70F during the month of September is rare indeed, having happened only in 1897, 1927, 1939, 1948, and 1955. Should nighttime lows remain in the 70s F both Friday and Saturday (Sept 22-23) it will be the latest ever such occurrence.

In addition, a significant feature of this September warm spell is the high dew points. A new daily high dew point record was set in the Twin Cities on September 21 (Thursday) this week with a reading of 70 degrees F at MSP Airport. As a result a Heat Advisory was released for many portions of Minnesota on Friday, September 22nd. Many new daily high dew point records are likely to be set on Friday and Saturday too, as dew points spike into the 70s F. Already a new record high dew point was set at 8am on Friday morning at MSP with a reading of 71 degrees F, while the record for Saturday, September 23 is 73 degrees F from 1945 and this may be threatened this weekend.

Weekly Weather Potpourri:


This week NOAA's Tom Di Liberto provides an analysis of the impacts of Hurricane Harvey on the Houston, TX area. It is an interesting article about the meteorology of the storm, but also the societal impacts.


The United Kingdom Met Office is celebrating 100 years of numerical weather forecasting this week. They trace the beginnings of their numerical weather forecasting back to the WWI era when Lewis Fry Richardson began to use spatial grids of meteorological measurements to calculate changes in forecast parameters such as temperature and moisture. What took him weeks to do back then, can be done by computers in less than one second today.


Earlier this week NASA reported that the extent of end-of-summer Arctic Sea Ice was the 8th lowest in the satellite record period going back to 1978. Arctic sea ice reached its annual minimum areal extent on September 13th, and is now starting to build again with the approach of the Northern Hemisphere winter season.

MPR listener question:


With this expected Heat Spell, what is the warmest overnight low temperature during September ever observed in Minnesota?

Answer:


In the Twin Cities climate record the warmest overnight low in the month of September was 77 degrees F on September 5, 1912. On a statewide basis the warmest September night was September 11, 1931 when the overnight low was 85 degrees F at Bird Island (Renville County). BTW that day was probably the warmest September day in Minnesota history with over 100 communities reporting afternoon highs in the 90s F and many places in western Minnesota well over 100 degrees F.

Twin Cities Almanac for September 22nd:


The average MSP high temperature for this date is 69 degrees F (plus or minus 10 degrees F standard deviation), while the average low is 49 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for September 22nd:

MSP records for this date include: highest daily maximum temperature of 95 degrees F in 1936; lowest daily maximum temperature of 49 degrees F in 1913 and 1983; lowest daily minimum temperature of 26 degrees F in 1974, 2007, and 2011; highest daily minimum temperature of 71 degrees F in 1937; record precipitation of 2.80 inches in 1895. No snow has fallen on this date in the Twin Cities.

Average dew point for September 22nd is 45°F; the maximum dew point on this date is 70°F in 1903; and the minimum dew point on this date is 20°F in 1974.

All-time state records for September 22nd:


The all-time state high temperature for today's date is 101 degrees F at Ada (Norman County) in 1936; the all-time state low for today's date is 10 degrees F at Thorhult (Beltrami County) in 1974. The all-time state record precipitation for this date is 4.84 inches at Cambridge (Isanti County) in 1968. Record snowfall is 2.0 inches at Baudette (Lake of the Woods County) in 1995.


Past Weather Features:


Strong thunderstorms brought three to six inches of rain to southern and central Minnesota over September 21-22, 1895. There were also many reports of hail. Fortunately crops had matured early that year and much of the harvest had already been completed. Widespread frost followed the thunderstorms.

By far the warmest September 22 in state history was in 1931 when over 40 Minnesota communities reported daytime highs in the 90s F. At seven locations the temperature reached 100 degrees F or greater.

The coldest September 22nd in state history was in 1974 when frost occurred in every corner of the state. Over two dozen climate stations in northern and western Minnesota reported morning lows in the teens F, and at Thorhult (Beltrami County) it was a nippy 10 degrees F. The high at Brainerd only rose to 41 degrees F.

An early autumn snow storm brought measurable amounts to western and northern parts of the state over September 22, 1995. Traces of snow were reported as far south as Luverne (Rock County), while in the north an inch or two was measured with temperatures in the upper 20s and low 30s F.

Strong and persistent thunderstorms brought record-setting rains to portions of southern Minnesota over September 22-23, 2010. Most southern Minnesota counties received over 6 inches of rain and parts of Faribault County received over 11 inches. Numerous roads were closed to flash flooding, and a week later the Mississippi River rose above flood stage.

Outlook:


Warm and humid over the weekend with chances for showers and thunderstorms. Continued chance for showers through early next week, but temperatures will decline near seasonal averages. Drier toward the end of next week.

Friday, September 15, 2017

Warm-up boosts crop maturation

Warm-up boosts crop maturation:


With the cold start to the month of September many farmers were concerned about corn and soybeans not reaching maturity before the first frost. The dramatic warm-up in temperatures this week (5 consecutive days with temperatures running from 6-12 degrees F warmer than normal) this concern has been mostly alleviated. Corn has matured rapidly this week, as have soybeans. In fact the degree of warm temperatures has been so persistent statewide that it has offset the cold start to the month, and now most climate stations are reporting mean September temperatures that are warmer than normal at mid-month. In addition warmer than normal temperatures are expected to prevail across Minnesota until near the end of the month. This may not only help with crop maturation, but accelerated dry-down before harvest season begins.

Rainfall has certainly been lacking this month, but I don't think this has had much effect on crop yields. The second half of September is supposed to be wetter than the first half.

Drought still present in parts of northwestern Minnesota:


Dryness has persisted most of the 2017 growing season in portions of northwestern Minnesota (canola, wheat, and sugar beet country). More recently portions of thirteen counties in the northwest have been designated to be in moderate drought (by the U.S. Drought Monitor), while portions of Marshall, Beltrami, and Lake of the Woods Counties have been designated to be in severe drought. Since May 1st or the start of the growing season many climate stations in this part of the state have measured 30 to 40 percent less than normal rainfall. A few areas have received less than half of normal rainfall for the growing season. In these areas they are hoping for a wet autumn season to replenish depleted soil moisture supplies.


Weekly Weather Potpourri:


The Minnesota State Climatology Office has recently developed climographs (monthly graphical depictions of temperature and precipitation normals) for all climate stations in the state. These are very useful for looking a different climates within the state, and also if you are traveling around the state. You can find these graphics and data under the header Climograph Portal.


Storm Aileen (not a tropical storm but a mid-latitude cyclone) brought high winds and rains to portions of the United Kingdom this week. This intense low pressure system produced winds of 55-65 mph across portions of Cheshire, Lancashire, Derbyshire, Yorkshire, and Nottingshire earlier this week. Some wind gusts close to 70 mph were reported.


Elsewhere in the East China Sea Typhoon Talim was churning with winds over 110 mph, producing wave heights of 30-35 feet. After bringing rains to parts of South Korea, it is expected to turn northeast and head towards Japan over the weekend. A second typhoon, Dokshuri, is expected to bring heavy rain to Vietnam this weekend.


A recent study from Indiana University documents that people affected by extreme weather or climate events do initially support policies to improve climate adaptation and resilience, but that response is relatively short-lived. Their longer term attitudes towards climate change are more heavily governed by their political beliefs or political party affiliations.


NOAA features an article this week on expanding malaria zones in Ethiopia as a result of warming temperatures, especially at higher elevations. This is mostly due to rising minimum temperatures rather than maximum temperatures.


AGU-EOS released an interesting paper this week about the warmer ocean temperatures and rising sea level measurements. These measurements clearly relate to global climate change, and the upward trends are substantial. Dr. John Abraham from University of St Thomas in St Paul contributed to this study.

MPR listener question:


The 91 degrees F at MSP on September 14 this week was the first reading of 90°F or higher here since July 22. How often does September bring 90 degrees F days following an August that does not bring any?

Answer:


This is rare and has happened only 8 times since 1871, the most recent year was 2011, when there were no 90°F days in August, but 3 such days in September.

MPR listener question:


Last week I heard you talk to Cathy about the September snow storms of 1912 and 1942. But, my grandmother wrote about having a snow storm interrupt the wheat harvest in Dakota County in September of 1916. Can you shed any light on that?

Answer:


Indeed, the crop harvest was later than normal in 1916 so wheat harvesting was underway in September when an early winter storm crossed the state on the 15th of September. Strong winds (>30 mph) and low temperatures pushed the wind chill into the 20s F statewide and a mixture of rain and snow fell in 18 counties, with the snow ranging from a trace to 0.3 inches. This disrupted the harvesting of all crops including wheat, corn, and potatoes. Widespread frost was reported as low temperatures ranged from 23 degrees F to 32 degrees F across half of the state. In many northern Minnesota communities the daytime high temperatures never rose above the low 40s F.

Twin Cities Almanac for September 15th:


The average MSP high temperature for this date is 72 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 53 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for September 8th:

MSP records for this date include: highest daily maximum temperature of 98 degrees F in 1939; lowest daily maximum temperature of 46 degrees F in 1916; lowest daily minimum temperature of 36 degrees F in 1964, 2007, and 2011; highest daily minimum temperature of 72 degrees F in 1897; record precipitation of 1.97 inches in 1997. A trace of snow fell on this date in 1916.

Average dew point for September 8th is 48°F; the maximum dew point on this date is 72°F in 1994; and the minimum dew point on this date is 19°F in 2011.

All-time state records for September 8th:

The all-time state high temperature for today's date is 100 degrees F at St Peter (Nicollet County) in 1939 and at Tracy (Lyon County) in 1955; the all-time state low for today's date is 17 degrees F at Bigfork (Itasca County) in 1964. The all-time state record precipitation for this date is 4.98 inches at Winona Dam (Winona County) in 2004. Record snowfall is 0.2 inches at Warroad (Roseau County) in 1916.

Past Weather Features:


Snow blanketed much of the state on September 15, 1916. This was one of the earliest snows ever across so much of the state landscape. Snow flurries were even observed in the Twin Cities from 10:30 am to 12:30 am, with wind chill conditions that felt like 28 degrees F.

The hottest September 15th in state history was in 1939 when over 50 climate stations reported afternoon high temperatures in the 90s F, records that still stand. St Peter, Springfield, and New Ulm hit the century mark on the thermometer. In many areas the overnight low temperature never dropped below 75 degrees F.

The coldest September 15th in state history was in 1964, when approximately 90 climate stations reported low temperatures of 32°F or colder. More than 60 communities reported morning lows in the 20s F, bringing an abrupt end to the growing season.

September 14-15 brought thunderstorms and heavy rains to parts of southern Minnesota. Many communities reported 8 to 13 inches of rain, and flash floods were declared in 13 southern Minnesota counties. There were many road and highway closures. More on this historic storm can be found at the Minnesota State Climatology Office.

Outlook:


Generally cloudy over the weekend with a chance for showers and thunderstorms on Saturday. Highs will dip below normal on Sunday. Temperatures will warm up above normal beginning on Tuesday of next week, but the daily chance for shower activity will increase as well.



Friday, September 8, 2017

September starts cool and dry

September starts cool and dry:


The month of September has begun cooler and drier than normal across the state. This helped to boost attendance over the final days of the State Fair. Temperatures for the month so far are running from 2 to 6 degrees F cooler than normal, and over 20 northern Minnesota climate stations have already reported morning lows in the 30s F. The coldest spots so far are Fosston (Polk County) with a reading of just 30 degrees F on the 6th and Crane Lake (St Louis County) with a reading of 30 degrees F on September 8th.

On Labor Day, September 4th a strong cold front crossed Minnesota during the afternoon bringing some showers and rapid temperature change. In St Cloud the temperature dropped over 21 degrees F in less than an hour during mid-afternoon, while in the Twin Cities the temperature dropped 10 degrees F in just 10 minutes during the late afternoon. Winds gusted to between 40 and 50 mph with the cold front passage. Many people at the State Fair sought shelter from the rain as well as warmer clothes.

The Galveston Hurricane of September 8, 1900:


On Saturday, September 8, 1900 between 6,000 and 8,000 people perished in Texas as a result of the landfall of the famous Galveston Hurricane. This storm is the center piece in the famous and popular book "Isaac's Storm" which documents the efforts of Dr. Isaac Cline, Director of the Galveston Weather Office in his attempts to warm residents of Galveston about the risks of this storm.

Three days following the landfall of the Galveston Hurricane, its remnant low pressure center had migrated north into portions of Missouri and Iowa, and brought thunderstorms and heavy rains to many parts of southern Minnesota. Many climate stations reported 2 to 5 inches of rain over September 11-12, and parts of Blue Earth County reported nearly 6 inches, a record amount that still stands today. Fall harvest activity was very delayed that month as a result of wet soils.

More on hurricanes and Minnesota weather can be found at the Minnesota State Climatology Office web site.

Weekly Weather Potpourri:


The NOAA National Hurricane Center is obviously having a very busy week monitoring the movements and intensity of three hurricanes: Katia in the southwestern part of the Gulf of Mexico, off the coast of eastern Mexico; Jose in the Central Atlantic Ocean just east of the Lesser Antilles; and Irma now passing between Cuba and the Bahamas. Earlier in the week NOAA announced that Irma was one of the strongest and largest hurricanes to ever form in the Atlantic Ocean. It remains a very serious threat to Florida and the Carolinas as we head into the weekend.


A new study released by the United Kingdom MetOffice in cooperation with the Woodland Trust reveals that earlier spring budburst for nine of eleven tree species is clearly related to a signal of climate change, warmer temperatures in March. Larch and Alder are two of the tree species most affected by this.


A recent study from Scientific Reports documents that ice-ocean albedo (reflectivity) feedbacks play a critical role in the variation and long term loss of Arctic Sea ice. This is a significant factor year to year in the ongoing seasonal loss of Arctic ice cover, which appears to be declining rapidly in the summer season in each passing year.

Earth and SpaceScience News editor Mohi Kumar was in Houston, TX during the passage of Hurricane Harvey last week and wrote a day by day account of the storm. It makes for a very interesting read and is written as an accounting by a survivor.

MPR listener question:


What has been the biggest snow storm in Minnesota during the month of September?

Answer:


There have been two large ones which caused a great deal of disruption. Both occurred a long time ago. Over September 24-25, 1912 an early winter storm delivered a mixture of sleet and snow to northern Minnesota. Observers there reported 2 to 6 inches of snow, while parts of Polk County reported up to 7 inches of snow. Over September 25-26, 1942 a storm brought a mixture of rain, sleet, and snow to many parts of the state. In many areas the total snowfall ranged from 4 to 8 inches. Roads were even plowed in Renville County following this storm.

Believe it or not both of these late September snow storms were followed by 70°F and 80°F days in early October!

MSP Local Records for September 8th:

MSP records for this date include: highest daily maximum temperature of 99 degrees F in 1931; lowest daily maximum temperature of 54 degrees F in 1929; lowest daily minimum temperature of 36 degrees F in 1883; highest daily minimum temperature of 74 degrees F in 1931; record precipitation of 1.52 inches in 1885. No snowfall has occurred on this date.

Average dew point for September 8th is 55°F; the maximum dew point on this date is 73°F in 1947; and the minimum dew point on this date is 25°F in 1995.

All-time state records for September 8th:

The all-time state high temperature for today's date is 105 degrees F at New Ulm (Brown County) in 1931; the all-time state low for today's date is 20 degrees F at Red Lake (Beltrami County) in 2000. The all-time state record precipitation for this date is 5.54 inches at Young America (Carver County) in 1991. No snow has fallen on this date.

Past Weather Features:


The warmest September 8th for Minnesota was in 1931 when over 30 communities reported afternoon temperatures of 100 degrees F or higher. In western Minnesota the overnight temperature never dipped below 76 degrees F at Milan, Canby, and Montevideo. Some people slept on their porch or on the lawn outside.

The coldest September 8th was in 1956 when 15 Minnesota climate stations reported low temperature in the 20s F, bringing an early end to the growing season.

Thunderstorms brought heavy rains to many parts of the state over September 8-9, 1991. Many climate stations reported rainfall totals of 3 to 7 inches, with many flooded roads and highways. New London in Kandiyohi County reported over 8 inches of rain.

Outlook:



Partly cloudy with a warming trend over the weekend, and generally dry weather. Continued warmer than normal temperatures through much of next week with little chance for precipitation.

Thursday, August 31, 2017

August Climate Summary

August Climate Summary:


Mean August temperature values from around the state were generally 2 to 4 degrees F cooler than normal. Only the second cooler than normal month in 2017 (May was the other). Extreme temperatures for the month ranged from 93 degrees F at Granite Falls (Yellow Medicine County) on August 1st, and just 30 degrees F at Embarrass, Brimson, and Crane Lake on the 25th. Some observers in St Louis, Lake, Cook, and Koochiching Counties reported frosts during the month. Minnesota did not report the nation's lowest on any date this month.

The most noteworthy climate attribute of August was the rainfall. Overall the statewide average rainfall was over 5 inches, ranking as the 11th wettest month of August in state history. Some western and southern communities reported their wettest August in history with total rainfall values over 10 inches. Redwood Falls topped the state network reports with over 13 inches. They reported the largest ever 1-day rainfall on August 17th in state history with a measurement of 8.12 inches. In addition over 40 climate stations in the state reported at least one new daily rainfall record during the month.

Destruction from Harvey may be the weather story of the year:


Large and slow-moving Hurricane Harvey (later Tropical Storm Harvey) brought widespread flooding and devastation to many parts of southeastern Texas last weekend and earlier this week, most especially the Houston Metropolitan Area. Many communities in Jefferson, Galveston, and Harris Counties reported over 40 inches of rain from this storm, topped by 51.88 inches in the Cedar Bayou-Mont Belvieu area of the Eastern Metro Area, a value that is the largest amount of rainfall ever measured from a Tropical Storm. Flooding issues were compounded in Beaumont, TX (pop 120,000) when there water supply pumps failed, preventing access to fresh water for all the residents there. More recently over Wednesday-Thursday Harvey brought 10 to 20 inches of rainfall to portions of western and southern Louisiana. Over the coming Labor Day weekend remnants of Harvey as a low pressure system will move northeast, not affecting Minnesota but ending up on the North Atlantic Ocean. Further coverage on Harvey can be found at the Weather Underground web site.

State Fair Weather Quiz:


The Annual Minnesota State Fair continues through Labor Day (September 4th). We had a good time on August 29th broadcasting the Annual Minnesota Weather Quiz from the MPR Booth (corner of Judson and Nelson on the fairgrounds). For those who would like to take the quiz (so far nearly 600 people have taken it), it is still available online at the MPR web site.


Weekly Weather Potpourri:


This week, the United Kingdom Met Office provided a brief climate summary of the summer season (June-August) noting that it has been very wet and warmer than usual in 2017. For Scotland it has been their 5th wettest summer historically.

Also this week NOAA's Jake Crouch presents an analysis of the climate patterns across the USA so far this year. He makes some interesting observations about severe weather and the pattern of warm and dry years versus the pattern of wet and cool years. You can read more at NOAA web site.

Following all of the attention on Hurricane and Tropical Storm Harvey this week, the NOAA National Hurricane Center is tracking Hurricane Irma in the Eastern Atlantic Ocean. It is expected to strengthen to a Category 4 hurricane as it travels westward across the Atlantic Ocean towards Puerto Rico next week. This system will be closely monitored all of next week. Elsewhere in the Eastern Pacific Ocean, Tropical Storm Lidia was being monitored a may bring heavy rains and wind to portions of Mexico and Baja California over the weekend, while in the Western Pacific Ocean, Typhoon Sanvu was growing stronger and may bring rain and high seas to portions of Japan over the weekend.

With the school year starting, many science teachers are looking for engaging materials to use with their students. NOAA's Data in the Classroom Program provides some great real-time data for students to better understand atmospheric and ocean sciences. There are curricula materials on El Nino and Sea Level variations, Coral Bleaching, Ocean Acidification, and Water Quality.

A recent paper appearing in the Proceedingsof the National Academy of Sciences documents how climate change will alter the seasonality and geographic distribution of peak electricity loads across Europe. Southern portions of Europe will eventually use more electricity than northern Europe, and summer peak loads will be higher than those of winter. This is an interesting result of the disparity in climate change impacts across the European nations.

MPR listener question:

You mentioned during the State Fair broadcast of the Minnesota Weather Quiz this week that "rain begets rain" and that "drought begets drought." That sparked a conversation in our family that produced these two questions: What is the longest streak of consecutive days with measurable rainfall in the Twin Cities? Also, what is the longest streak of days with no precipitation in the Twin Cities?

Answer:

The longest stretch of consecutive days with measurable rain is from a long time ago, May 30, 1883 to June 9, 1883, 11 days. It rained at least .03 inches each day, with an 11 day total of 3.95 inches in the Twin Cities. No flooding was reported, but a lightning storm took out the telegraph lines across southern Minnesota during this interval. The most recent exceptionally long streak of consecutive days with precipitation was April 5 to April 14, 2013 (10 days) when a mixture of rain and/or snow occurred each day, totaling 6.8 inches of snow and 2.73 inches of precipitation.

The longest stretch of days when no measurable precipitation occurred was from November 15, 1943 to January 4, 1944, a period of 51 days. There were some dates in this interval when a trace of precipitation was reported. The most recent long spell of dry weather was September 26 to October 22, 2010, a period of 27 days.

Twin Cities Almanac for September 1st:


The average MSP high temperature for this date is 77 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 59 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for September 1st:

MSP records for this date include: highest daily maximum temperature of 97 degrees F in 1913; lowest daily maximum temperature of 59 degrees F in 1951; lowest daily minimum temperature of 36 degrees F in 1974; highest daily minimum temperature of 74 degrees F in 1937 and 1953; record precipitation of 3.29 inches in 1942. No snowfall has occurred on this date.

Average dew point for September 1st is 56F; the maximum dew point on this date is 75F in 1997; and the minimum dew point on this date is 30F in 1946.

All-time state records for September 1st:

The all-time state high temperature for today's date is 101 degrees F at Beardsley (Big Stone County) in 1913; the all-time state low for today's date is 23 degrees F at Tower (St Louis County) in 1974. The all-time state record precipitation for this date is 7.70 inches at Nett Lake (St Louis County) in 1973. No snow has fallen on this date.

Past Weather Features:


The warmest ever September 1st came in 1913 when most areas of the state saw afternoon temperatures climb into the 90s F. Five locations surpassed 100 degrees F. St Peter started the day with a cool morning of 52 degrees F, but under sunny skies warmed up to 98 degrees F by 4pm.

Very strong thunderstorms moved across the state over August 31 and September 1, 1973 bringing very heavy rains and flash flooding to portions of northern. Rainfall totals from 4 to 8 inches occurred in portions of Clay, Mahnomen, Polk, and St Louis Counties. An unusual tornado passed between Big Falls and Little Fork in Koochiching Counties, destroying many farm buildings and some mobile homes.

By far the coldest September 1st in state history was in 1974. Many parts of the state saw widespread frosts. Over 40 climate stations reported freezing temperatures in the morning, representing 23 of Minnesota's 87 counties. Frost damage to crops, both corn and soybeans, was widespread as well.

Outlook:


Mostly sunny weekend with near normal temperatures. Chance of showers later in the day in the north on Labor Day. Cooler temperatures and chance for showers on Tuesday, and continuing cooler than normal temperatures for much of next week.

Friday, August 25, 2017

Record-setting wet August for some, first frosts in the north

Record-setting wet August for some:


Over 40 climate observers across the state report over 6.5 inches of rainfall for this month, roughly twice the normal amount. With a week to go these numbers will certainly increase. For some locations it has already been a record-setting wet month. This is true for the following locations:
Redwood Falls (Redwood County) 13.03 inches Granite Falls (Yellow Medicine County) 11.09 inches
Montevideo (Chippewa County) 10.43 inches
Hawley (Clay County) 10.43 inches
Bird Island (Renville County) 10.41 inches
Vesta (Redwood County) 9.62 inches

In addition over 60 new daily rainfall records have been set this month within the Minnesota climate observation network.

First freezing temperatures this month:


On Thursday morning, August 24th, this week the first sub-freezing temperatures were reported with a 32°F reading at Isabella (Lake County), and just 30°F at Crane Lake and Embarrrass (St Louis County). At least 8 other climate stations reported morning lows in the 30s that morning. The readings of 30 degrees F at Embarrass and Crane Lake on August 24th was their first sub-freezing temperature since June 1st, while at Isabella, the 32 degrees F was the first frost since May 19th. It is not unusual to have frost at these locations during the month of August, and more temperature readings in the 30s F (such as occurred again Friday morning) are likely to occur in northern areas later this month.

State Fair time:


The Annual Minnesota State Fair will began Thursday, August 24th and runs through Labor Day, September 4th. It appears that the beginning days of the Fair will be cooler than normal temperatures, perhaps just in the 60s and 70s F. Also there are chances for repeated shower activity over the Friday through Sunday period, then drier next week. I will be at the MPR Booth (corner of Judson and Nelson on the fairgrounds) on two dates: Friday, August 25th at noon to record the TPT Almanac public affairs program with hosts Cathy Wurzer and Eric Eskola; and then again on August 29 (Tue) with host Tom Weber at 11am to broadcast the annual Minnesota Weather Quiz. Please stop by if you are at the Fair either of those days.

Weekly Weather Potpourri:


The NOAA National Hurricane Center was issuing warnings on Hurricane Harvey this week in the Gulf of Mexico. Harvey was expected to strengthen and produce sustained winds up to 120 mph, with higher gusts as it approached the coastline of Texas (around Corpus Christi and northeast to Sargent). Storm surge estimates range from 6 to 12 feet, and rainfall estimates typically range from 15 to 25 inches for this storm. In the Western Pacific Ocean Tropical Storm Pakhar was approaching the Philippines and is expected to bring heavy rains and high seas there for Friday and Saturday.


This week the New York Times published a well-documented study of the loss of permafrost in the state of Alaska. The pace of loss is greatly accelerated in the context of historical climate behavior, and concern is expressed over the amount of carbon that will be released in the thawing of vast amounts of permafrost in the Alaska landscape over the next century.


This week marked the 150th Anniversary of the birth of the iconic "Shipping Forecast" in the United Kingdom, founded by the famous Vice-Admiral Robert FitzRoy who captained the HMS Beagle during Charles Darwin's expedition. The Shipping Forecast is one of the most widely listened to broadcasts on the BBC. The UK Met Office and BBC posted interesting story about this.


Scientists from the University of Copenhagen reported this week from a study of Lake Catalina in East Greenland that using satellite data they have found evidence of four huge outburst floods over the past 50 years, each of which released over a half and up to one cubic mile volume of fresh water into a fjord.

MPR listene question:


I heard you talk to Cathy last week about Redwood Falls having its wettest August in history this year. Isn't August also the month with the most rainfall in history for Minnesota? I want to say this happened in 2007.

Answer:


For an individual location you are right. The all-time state record is 23.86 inches at Hokah (Houston County) in 2007. But on a statewide basis, August has not been our wettest month. Our wettest month on a statewide basis was June 2014 when the average rainfall from all observations across the state was 8.07 inches. List below are the top ten wettest months in history based on the statewide average rainfall reported from all climate stations.

(1) June 2014 8.07”

(2) Tie between July 1897 and June 1914 7.32”

(3) June 1905 6.83”

(4) August 1900 6.80”

(5) June 1915 6.72”

(6) June 1984 6.68”

(7) June 1957 6.67”

(8) June 1925 6.65”

(9) June 1944 6.54”(10)September 2010 6.41”

Twin Cities Almanac for August 25th:

The average MSP high temperature for this date is 79 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 61 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for August 25th:

MSP records for this date include: highest daily maximum temperature of 96 degrees F in 2013; lowest daily maximum temperature of 60 degrees F in 1958; lowest daily minimum temperature of 41 degrees F in 1887; highest daily minimum temperature of 80 degrees F in 2013; record precipitation of 1.51 inches in 1960. No snowfall has occurred on this date.

Average dew point for August 25th is 58°F; the maximum dew point on this date is 75°F in 1990; and the minimum dew point on this date is 26°F in 1934.

All-time state records for August 25th:


The all-time state high temperature for today's date is 102 degrees F at St Vincent (Kittson County) in 1886; the all-time state low for today's date is 25 degrees F at Littlefork (Koochiching County) in 1915. The all-time state record precipitation for this date is 5.08 inches at Pokegama Dam (Itasca County) in 1941. No snow has fallen on this date.

Past Weather Features:


Hot weather prevailed across the state on August 25, 1886. Most areas saw afternoon temperatures climb to 90°F plus, while portions of the Red River Valley recorded afternoon highs of 100 degrees F or greater.

Spectacular northern lights were observed across the sky all over the state of Minnesota on August 25, 1916 from 8pm to midnight. The aurora was so brilliant it was even visible for Twin Citie’s residents, rare indeed and almost unheard of today.

August 25th in 1917 was a cold one. Five communities in northern Minnesota reported frosts, while a number of communities reported daytime high temperatures that only reached the 60s F, and with a cool northwest wind felt even colder.

A system of organized thunderstorms known as a "derecho" crossed the state over August 25-26, 1990 producing heavy rains and strong winds, estimated at 70 to 80 mph. Many observers reported rains of 3-6 inches which produced widespread flash flooding. The strong winds damaged many farm buildings and caused power outages across Douglas, Grant, Wilkin, Big Stone, and Otter Tail Counties in western sections of the state.

The hottest August 25 in the modern era was in 2013 when over 100 communities reported afternoon temperatures in the 90s F. The afternoon Heat Index surpassed 100 degrees F at a number of locations. The nighttime temperatures were warm too, not falling below 75 degrees F at over 30 locations.

Outlook:


A cloudy weekend coming up with chances for showers and thunderstorms each day. Cooler than normal temperatures will prevail through the weekend. Drier weather on Monday, then a warming trend begins on Tuesday, with a drier pattern in place for much of next week.

Friday, August 18, 2017

What a rainy week!

What a rainy week!

Over the past week many parts of the state have reported rainfalls totaling over 5 inches. Thunderstorms over August 13-14 brought record-setting rainfall to some Minnesota communities, including: 3.75 inches at Montevideo; 3.00 inches at Alexandria; 2.20 inches at Windom; 2.04 inches at Long Prairie; and 1.38 inches at Grand Portage.

Then even heavier rains came over August 16-17 this week, along with a few tornadoes in Nicollet, Sibley, and Blue Earth Counties, all very short-lived. The rainfall in these thunderstorms was record-setting at many locations, even more so than the rains earlier in the week. Some of the new record amounts were:
8.12 inches at Redwood Falls (many flooded basements); 4.11 inches at Willmar; 3.98 inches at Vesta; 3.66 inches at Marshall; 3.57 inches at Montevideo; 3.18 inches at Melrose; 2.88 inches at Pokegama Dam; 2.73 inches at Lake City; 2.67 inches at Pipestone; 2.66 inches at Lakefield; and 2.49 inches at Pine River Dam. The 8.12 inches at Redwood Falls was a new statewide record for August 16th. The Redwood River at River Falls rose nearly 4 feet, while the Minnesota River at Montevideo rose over 6 feet in response to these heavy rains.

No hail reports were associated with these storms, but some thunderstorm associated winds damaged trees in McLeod, Renville, and Redwood Counties.

Redwood Falls with 11.15 inches of rain, and Montevideo with 9.98 inches have already recorded their wettest month of August in history, and there are still two weeks to go. More heavy rain is expected across the southern half of the state over August 20-21.

State Fair Time:


The Annual Minnesota State Fair will begin next Thursday, August 24th and run through Labor Day, September 4th. It appears that the beginning days of the Fair will be sunny and dry with cooler than normal temperatures, perhaps just in the 70s F. I will be at the MPR Booth (corner of Judson and Nelson on the fairgrounds) on two dates: Friday, August 25th at noon to record the TPT Almanac public affairs program with hosts Cathy Wurzer and Eric Eskola; and then again on August 29 (Tue) with host Tom Weber at 11am to broadcast the annual Minnesota Weather Quiz. Please stop by if you are at the Fair either of those days. For other MPR activities and events going on at the State FAir visit the MPR web site.

University of Minnesota Extension will be well represented at the State Fair as well, offering programs and visits with specialists and educators. For more information visit the Extension web site


Weekly Weather Potpourri:

NASA scientists reported this week that wildfires burning just west of the Greenland ice sheet and depositing a great deal of soot and ash on the ice. This may hasten further melting of the Greenland ice sheet for the balance of summer. It was also reported that at least one community in Greenland had dispatched some firefighters to investigate and perhaps even help suppress these fires, which are likely occurring in peatland landscapes.


NOAA reported that the month of July 2017 was the 10th warmest in history across the contiguous USA. In addition they report that the first seven months of 2017 (January through July) were the 2nd warmest in history for the contiguous 48 states, 3.2°F above the 20th Century average.


In related news, the Washington Post reported this week that Death Valley reported the hottest singular month in world history with a July 2017 mean temperature of 107.4 degrees F. This was over 5 degrees above normal for the month there. The extreme high temperature for the month was 127°F on the 7th, while the extreme low temperature was 89°F on the 5th and the 25th. On three nights the temperature never fell lower than 102 degrees F. Other western USA cities like Reno, NV and Salt Lake City, UT also reported their hottest month in history during July of 2017.


In this week’s Earth and Space Science News Sarah Witman reports on the value of expanded rain gauge deployment to help water resource planners better manage streamflow and other hydrologic attributes.

Twin Cities Almanac for August 18th:


The average MSP high temperature for this date is 80 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 62 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for August 18th:

MSP records for this date include: highest daily maximum temperature of 98 degrees F in 1976; lowest daily maximum temperature of 61 degrees F in 1890; lowest daily minimum temperature of 41 degrees F in 1977; highest daily minimum temperature of 77 degrees F in 1916; record precipitation of 2.26 inches in 1907. No snowfall has occurred on this date.

Average dew point for August 18th is 59°F; the maximum dew point on this date is 79°F in 1995; and the minimum dew point on this date is 36°F in 2004.

All-time state records for August 18th:


The all-time state high temperature for today's date is 107 degrees F at Browns Valley (Traverse County) in 1976; the all-time state low for today's date is 24 degrees F at Tower (St Louis County) in 1975. The all-time state record precipitation for this date is 5.78 inches at Artichoke Lake (Big Stone County) in 1935. No snow has fallen on this date.

Past Weather Features:


About 7:30 pm on August 18, 1907 an EF-2 tornado (winds around 135mph) passed near Maple Plain (Hennepin County) destroying 15 cottages on Lake Independence. It was on the ground for 20 miles, killing one person and injuring 15. A barn was destroyed killing five horses inside.

There was an autumn-like chill in the air on August 18, 1915. Some northern Minnesota communities reported frost, and in southern Minnesota at Caledonia (Houston County) the thermometer struggled to climb into the low 60s F.

Widespread frost was reported in northern Minnesota counties on August 18, 1975. At Roseau the morning low was 30 degrees F, and the afternoon sun only warmed the temperature into the upper 50s F, feeling more like October than August.

By far the warmest August 18th in history was in 1976 when 30 Minnesota communities saw the thermometer top 100 degrees F or higher. The temperature at Redwood Falls and Montevideo never dropped lower than 78 degrees F that day.

Persistent thunderstorms brought heavy rains to southern and western Minnesota over August 18-20, 1990. Many areas reported 3 to 6 inches of rainfall and flooded roads were common in Swift, Chippewa, and Kandiyohi Counties.

Outlook:


A mostly sunny weekend with high temperatures near average for this time of year. Then, there will be increasing cloudiness later on Sunday with a chance for showers and thunderstorms by Sunday night. The chance for showers will carry over into Monday with persistent cloudiness that may affect viewing of the eclipse. Cooler and drier will prevail for Tuesday through Thursday of next week.

Friday, August 11, 2017

August climate trends

August climate trends:


Since the record-setting cold August of 2004, the month of August has been warmer than normal 75 percent of the time (9 years out of 12) in Minnesota. Over the same time period the August rainfall has been quite mixed, with 3 years near normal, 4 years drier than normal, and 5 years wetter than normal. Last year, 2016 brought the 7th wettest month of August in state history, with average rainfall across the state totaling close to 5.5 inches.

So far the pattern for this August (2017) has favored cooler than normal temperatures with highly variable rainfall. Brimson, Embarrass, Hibbing and Crane Lake have already reported morning lows in the 30s F. Thunderstorms over August 3-4 brought 1 to 2 inch rains to some parts of the state, and even set new daily records for some climate station. Canby reported a record 1.87 inches of rain on the 3rd, while Rochester and Minnesota City reported record rainfalls on the 4th with 2.01 inches and 2.13 inches respectively. August 9th also brought thunderstorm rainfall to portions of Minnesota with some observers reporting well over 1 inch. Cass Lake (Cass County) reported a record 1.66 inches, while Wadena reported a record 1.41 inches.

For the balance of the month it appears cooler than normal temperatures may persist, and a wetter than normal pattern for the remainder of the month is also projected.

Climate Change and Isle Royale National Park:


I recently visited Isle Royale National Park with my wife. We learned a great deal about the natural resources and wildlife there, even saw some moose. Isle Royale has been in the National Park system since 1940, and there are three automated weather stations deployed across the island, plus the cooperative climate station on Mott Island run by the National Park Service since November of 1940. Data are generally available for the May-September period as the park is not staffed from October through April, except for those conducting biological research. Though climate measurements there are not comprehensive enough to do a trend analysis, most of the warmest summers at Isle Royal have occurred since 1983, with the record warmest in 1998. Because Lake Superior slowly warms all summer, releasing higher quantities of water vapor with each passing month, the wettest months there are traditionally in August and September, when monthly rainfall has exceeded 8 inches.

There are some climate change impacts going on there which have caught the attention of the National Park Service. Some of these include:
-Generally warmer winters have caused less frequent ice bridges which provide a means for wildlife to travel from the island to the mainland (usually Ontario, Canada or Minnesota). This is associated with a decline in the wolf population which now stands at only two.
-With rising temperatures some of the inland lakes on Isle Royale have been warming to the point where cold water fish like the Cisco can no longer survive in them. Water temperatures above 67 degrees F are not suitable for Cisco.
-Some Arctic plant species, like the pale paintbrush, may slowly disappear from the island as a result of warming temperatures.
-Warmer springs are linked to more abundant winter ticks, which live on moose and produce added stress. Moose already suffer from some stress due to warmer summer temperatures, and therefore spend more time in the cool waters of the island.

Obviously as the climate continues to change around Lake Superior, Isle Royale will see even more impacts in the future. More information on climate change as it relates to Isle Royale National Park can be found in a report by the Great Lakes Integrated Sciences andAssessment Program.

Weekly Weather Potpourri:


On Thursday, August 10, NOAA released the 2016State of the Climate Report. It is well worth the read, or at least reading the highlights of the report. Some of the main points included:
-A record warm year globally in 2016, third consecutive year of record warmth
-A record rise in sea level in 2016, and a record high in global sea surface temperature, strong El Nino
-Continued rapid loss of Arctic sea ice, as the Arctic warms at twice the rate of the lower latitudes
-Mass of the Greenland ice sheet reaches a record low in 2016
-a record low spring snow cover was measured over the North American Arctic in 2016


In somewhat related news the Finnish Ice Breaker MSV Nordica set a new record for the shortest transit time through the Arctic Northwest Passage, cutting a path from Alaska to Greenland over a period of just 24 days this summer. You can read more at NOAA News Features.


A recent study from the University of Illinois documents how climate change, through late winter or early spring warming, can cause different grass plants to prematurely break dormancy and start growing rigorously, only to be confused by the shorter days that still persist. They then grow shorter shoots, or stop growing entirely, waiting for day length to get long enough to resume grow.


A study recently published in the journal Science documents that climate change, most notably winter warming, is causing more frequent late winter and early spring flooding across many European watersheds. This is the first comprehensive study that reveals this effect of climate change.

MPR listener question:

Here near Roseau, MN we have recorded no measurable rainfall so far this month. Has there ever been an August with no rainfall?

Answer:

At Roseau the driest August in history was in 1894 when just 0.48 inches of rain fell. There are a few Minnesota climate stations that have recorded a completely dry month of August, including Crookston (Polk County) which received only a trace of rain in August of 1915, and more recently Warren (Marhsall County) which saw no rainfall in August of 2000.

Twin Cities Almanac for August 11th:


The average MSP high temperature for this date is 80 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 61 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for August 11th:

MSP records for this date include: highest daily maximum temperature of 97 degrees F in 1947; lowest daily maximum temperature of 65 degrees F in 1964 and 2004; lowest daily minimum temperature of 47 degrees F in 1968 and 2004; highest daily minimum temperature of 77 degrees F in 1947; record precipitation of 1.73 inches in 2007. No snowfall has occurred on this date.

Average dew point for August 11th is 57F; the maximum dew point on this date is 74F in 2007; and the minimum dew point on this date is 32F in 1999.

All-time state records for August 11th:


The all-time state high temperature for today's date is 105 degrees F at Wheaton (Traverse County) in 1947; the all-time state low for today's date is 28 degrees F at Embarrass (St Louis County) in 199t7. The all-time state record precipitation for this date is 8.06 inches at Hastings (Daktoa County) in 1945. No snow has fallen on this date.

Past Weather Features:


Strong thunderstorms crossed the state over August 10-11, 1909 bringing 3 to 5 inches of rain to many areas, especially northern counties. Detroit Lakes reported well over 5 inches, and many farm fields in Becker County were flooded.

A severe thunderstorm passed over Dakota and Goodhue Counties late on August 11 and over the early morning hours of August 12, 1945 bringing 6 to 8 inches of rainfall. Many roads and highways were flooded, along with several farm fields. The Zumbro River rose five feet above flood stage.

The hottest August 11th in state history was in 1947 when 10 Minnesota communities reported afternoon temperatures of 100 degrees F or higher. It was also a difficult night for sleeping as the temperature never dropped below 80 degrees F in some southwestern counties.

The coldest August 11th in state history was in 1997 when overnight temperatures fell into the 30s F across northern Minnesota. Frosts were reported in St Louis and Koochiching Counties.

Outlook:


Mostly sunny and cooler than normal temperatures across the state over the weekend. There will be a chance for scattered showers and thunderstorms later on Sunday, especially in southern counties. Cooler than normal temperatures will continue early next week as well. Temperatures will warm to near normal values by Wednesday with a chance for showers and thunderstorms.

Friday, July 28, 2017

WeatherTalk will be back August 11

WeatherTalk will not be published Friday, July 28 or August 4. Mark Seeley will send the next WeatherTalk on Friday, August 11.

Friday, July 21, 2017

Heavy Thunderstorms in Southern Minnesota

Heavy Thunderstorms in Southern Minnesota:

Fast moving heavy thunderstorms crossed portions of central and southern Minnesota over July 19-20 this week. These storms also brought strong winds, with many reports of wind gusts over 60 mph. Fortunately little hail was associated with these storms. The only area to report large hail was Windom (Cottonwood County) where hail stones up to 1.5 inches in diameter were observed.

The heaviest rains occurred in southeastern Minnesota counties and in western Wisconsin, where widespread street flooding, and even mudslides were reported. Many observers reported new daily record rainfalls, including:
5.11 inches at Minnesota City (Winona County)
5.03 inches at Wabasha (Wabasha County)
4.75 inches at La Crescent (Winona County)
4.55 inches at Red Wing Dam (Goodhue County)
4.50 inches at Winona Dam (Winona County)
3.89 incheds at Hokah (Houston County)
6.37 inches at Alma Dam (Buffalo County, WI)
6.26 inches at La Crosse (La Crosse County, WI)
4.80 inches at Hillsboro (Vernon County, WI)

More information on these storms can be found at the Minnesota StateClimatology office web site. Despite the recent rains, many parts of western Minnesota remain drier than normal for the month, with less than 1 inch of total rainfall so far.

Additional heavy rains were affecting southern Minnesota on Friday, July 21st as well, but total amounts were not yet available for this blog.

Topping 100 Degrees F:


Earlier this week on Monday July 17th the climate observer at Browns Valley (Traverse County) reported an afternoon temperature of 101 degrees F, the highest measured so far this year in Minnesota. Elsewhere Canby, Wheaton and Marshall all hit 98 degrees F that day.

The statistics for the past 40 years (my time as Extension Climatologist) show that 80 percent of the time (32 years), a temperature of 100 degrees F or higher is measured somewhere in the state. More often such readings come from western or southern Minnesota counties. For example, 19 of the 40 years the highest temperature in the state was measured in Traverse, Lyon, Lac Qui Parle, or Redwood Counties. These statistics conform to those of our state climate history all the way back to the second half of the 19th Century. Most of the all-time daily high temperature records for the state come from climate stations in Big Stone, Traverse, Lac Qui Parle, and Yellow Medicine Counties. On rare occasions the state's highest daily temperature for a given year may come from southeastern Minnesota, as was the case in 1985 when Theilman (Wabasha County) reported 103 degrees F on June 10th.

Interestingly enough, both the earliest and latest dates for measuring a temperature of 100 degrees F in state history are held by the same climate station. At Ada (Norman County), along Highway 9 in the Red River Valley, the temperature has reached 100 degrees F as early as April 21 (1980), and as late as September 23 (1936). So, if you like hot weather that is the place to choose. On the other hand, Ada has been as cold as -53 degrees F in the winter (Feb 15, 1936), so have some warm clothes for that season.

Only 1986, 1992, 1993, 1997, 2002, 2010,2014, and 2015 have produced no daily high temperatures of 100 degrees F or greater.

Special Conference at Macalester College this week:

"Transition US National Gathering: Growinga Movement for Resilient Communities" will take place at Macalester College over July 27-August 1. There will be workshops and presentation sessions related to planning and building more resilient communities, lowering carbon emissions, mitigating impacts of climate change, and building on social community strengths. Check out the web link for more information.

Weekly Weather Potpourri:

Earlier this month NOAA scientists announced that the Greenhouse Gas Index based on a global network of measurements of greenhouse gases in the atmosphere over oceans and land, has shown a rise of 40 percent since 1990. This is primarily based on a rise in carbon dioxide, although methane and nitrous oxide are some of the other important gases measured as well.

Also earlier this week NOAA scientists announced that the month of June 2017 on a global basis was the 3rd warmest of record going back to 1880. In addition the global average temperature for the first six months of 2017 was the 2nd highest ever for the same measured period (1880-20170, trailing only that of last year. You can read more at the NOAA News web site.

The United Kingdom Met Office had an interesting discussion online this week about common folklore wisdom related to weather. They dissected the accuracy of this folklore wisdom and found some of it to be valid, and some not so valid. One of the beliefs that proved to be highly invalid was that cows lie down before a rain storm.

A recent paper by Norwegian scientists in the journal Environmental Research Letters describes the disparities in the average carbon footprint among households across the European Union. It is interesting to note that the highest carbon footprints are from the United Kingdom and Greece.

MPR listener question:

It seems that we have had a real rollercoaster ride with temperatures around the state this month. Here in Ely half of the days have brought colder than normal temperatures, and half brought warmer than normal temperatures so far this month. Has Minnesota reported the either coldest or warmest temperature in the nations so far in July?

Answer:

Indeed temperatures have been highly variable so far this month. We have not reported the nation's highest temperature on any day this month, and we rarely do. For example, earlier this week on July17th when Browns Valley reported a daytime high of 101 degrees F, hundreds of climate stations in western states were warmer than that, topped by 124 degrees F at Death Valley. On the cold side though, Crane Lake, MN did report the coldest temperature in the Nation on July 14th with a morning low of just 37 degrees F. That conforms to our national reputation.

MSP Local Records for July 21st:

MSP records for this date include: highest daily maximum temperature of 105 degrees F in 1934; lowest daily maximum temperature of 69 degrees F in 1927 and 1947; lowest daily minimum temperature of 49 degrees F in 1947; highest daily minimum temperature of 79 degrees F in 1983; record precipitation of 1.36 inches in 1951. No snowfall has occurred on this date.

Average dew point for July 21st is 61°F; the maximum dew point on this date is 78°F in 1983; and the minimum dew point on this date is 40°F in 1947.

All-time state records for July 21st:

The all-time state high temperature for today's date is 113 degrees F at Milan (Chippewa County) in 1934; the all-time state low for today's date is 34 degrees F at Angus (Polk County) in 1947. The all-time state record precipitation for this date is 7.83 inches at Chaska (Carver County) in 1987. No snow has fallen on this date.

Past Weather Features:


By far the warmest July 21st in state history was in 1934. Over 30 Minnesota communities reported an afternoon temperature of 100 degrees F or greater, topped by 113 degrees F at Milan (Chippewa County). The heat was compounded by widespread drought as well. Even the overnight temperature never fell below 80 degrees F at Beardsley, Montevideo, Albert Lea, and Zumbrota making for a very difficult night to sleep.

The coldest July 21st in state history was in 1947 when 15 Minnesota communities reported morning lows in the 30s F. Some mid-summer ground frost was reported from St Louis and Polk Counties in northern Minnesota. The afternoon high temperature at Two Harbors only reached 62 degrees F.

Severe thunderstorms dropped heavy rainfall across southeastern Minnesota on July 21, 1951. Many climate stations reported 3 to 6 inches of rainfall which washed out roads and flooded highways. Caledonia in Houston County reported a record 6.60 inches. Flooding of homes and businesses in the Rochester area was widespread, and the Zumbro River saw one of its highest every flood crests.

Outlook:

Partly cloudy with near normal temperatures for Saturday, and mostly dry conditions. Cooler with below normal temperatures for Sunday through Tuesday, and little chance for rain. Then warming for Wednesday and Thursday to near normal temperatures with a chance for showers and thunderstorms.

Friday, July 14, 2017

Great Variation in Rainfall this Month

Great Variation in Rainfall this Month:


So far this month the rains across the state have been very widely scattered and highly variable in amounts, including those of this week. This is especially true in western and southern counties. Across Otter Tail County total rainfall in July varies from less than a third of an inch to well over 2 inches; and across Blue Earth County rainfall for the month varies from less than a half inch to nearly 3.5 inches. Overall rainfall totals through the first 14 days of the month ranged from just trace amounts in portions of southwestern to nearly 3.5 inches in south-central Minnesota. Severe thunderstorms on Sunday, July 9th brought hail and high winds to many areas. Some very large hail (over 2 inch diameter) were reported, along with a tornado near Lake Crystal (Blue Earth County). Then another severe weather episode with dew points in the 70s F occurred across portions of central Minnesota over July 11-12, bringing hail and high winds to many areas. There was also a report of a tornado near Forest Lake. At one point, Xcel Energy reported over 56,000 customers without power because of high winds. The Minnesota State Climatology Office features more detailed descriptions of all of these storms so far this month.

Following the warm and sultry weather which produced the thunderstorms a cold front brought morning lows in the 40s and 50s F on July 13th. Crane Lake dropped all the way down to 37 degrees F on July 14th. This is a typical Minnesota rollercoaster pattern on the thermometer readings.

Weather Potpourri:


NOAA scientists announced this week, that after a number of years with little or no rise in global methane (a powerful greenhouse gas), there is now a rising trend in global methane that has been evident in the data every year since 2007. This trend had been predicted to resume by global climate models.

Hurricane Fernanda, located many hundreds of miles southwest of Baja California is expected to intensify and perhaps become a Saffir Simpson Category 4 storm (winds 130-150 mph) over the weekend and early next week. But it will remain well out to sea in the Eastern Pacific Ocean and no threat to land.

Earlier this week an iceberg the size of the state of Delaware broke away from the West Antarctica Ice Shelf (called Larson C) and is now floating. This 2200 square mile iceberg, estimated to weigh over a trillion tons, is expected to occasional get stuck on the bottom of the Wendell Sea over the next months and years. The weekly Earth & Space Science News from AGU provides more detail and perspective on this topic.

MPR listener question:


When I listen to the weather forecast I get confused by the rainfall predictions when meteorologists use the terms isolated showers, widely scattered showers, scattered showers, and widespread showers. Can you explain the differences?

Answer:


This jargon issue has been written about over the years by many meteorologists, and there are certainly some geographic disparities in what these terms imply. For our region of the country they generally mean the following:

Isolated showers implies less than a 25 percent chance of occurrence anywhere in the forecast area.
Widely scattered showers implies a 30-40 percent chance.
Scattered showers implies a 40-60 percent chance.
Widespread showers implies over a 60 percent chance.
The bottom line is that when the terms isolated or widely are used, it is more likely to remain dry where you are located.

Twin Cities Almanac for July 14th:


The average MSP high temperature for this date is 84 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 65 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for July 14th:

MSP records for this date include: highest daily maximum temperature of 108 degrees F in 1936; lowest daily maximum temperature of 65 degrees F in 2014; lowest daily minimum temperature of 50 degrees F in 1930; highest daily minimum temperature of 79 degrees F in 1980; record precipitation of 3.17 inches in 1915. No snowfall has occurred on this date.

Average dew point for July 14th is 60 degrees F; the maximum dew point on this date is 76F in 1995; and the minimum dew point on this date is 40F in 1930.

All-time state records for July 14th:


The all-time state high temperature for today's date is 111 degrees F at New Ulm (Brown County) in 1936; the all-time state low for today's date is 30 degrees F at Alborn (St Louis County) in 1930. The all-time state record precipitation for this date is 5.49 inches at Carlos (Douglas County) in 2011. No snow has fallen on this date.

Past Weather Features:

Perhaps the coldest July 14 in state history came in 1930. At least 15 climate stations reported a morning low in the 30s F, and a few northern communities reported frost. The air was especially dry with humidity reported between 20 and 30 percent. For some northeastern climate stations the afternoon temperatures remained in the 60s F.

July 14, 1936 was the hottest in history with 50 Minnesota communities reporting an afternoon high temperature of 100 degrees F or greater. Overnight lows never cooled off close to normal and remained between 74 and 78 degrees F in most places. Many people slept outside or on their porches.

Strong thunderstorms passed over northern Minnesota July 14-15, 1937 delivering hail along with 3 to 6 inches of rainfall to many areas, including Baudette. In Baudette ended up with 12.50 inches for the month, recording the wettest July in history there.

Eight consecutive days with rain showers saturated southern Minnesota over July 9-16, 2011. Many climate stations reported 5 to 8 inches of rain over that period and some corn and soybean fields showed standing water.

Outlook:

Warm and humid on Saturday, with a slight chance of thunderstorms. Cooler on Sunday with temperatures falling back closer to normal. Temperatures warming again Monday and Tuesday to slightly above normal, with chances for showers and thunderstorms much of next week.














Friday, July 7, 2017

July Temperatures Following Trend

July Temperatures Following Trend:


Though the first several days of the month were cooler than normal, with the recent heat, most observers are now reported mean monthly temperatures that are warmer than normal. This follows the pattern for many recent trends. Five of the most recent seven months of July have been warmer than normal in Minnesota, while 21 of the past 23 months have been warmer than normal in Minnesota as well. The highest temperature of the summer so far was observed at Browns Valley (Traverse County) on Wednesday (July 6) of this week with an afternoon reading of 98 degrees F. In addition at least 15 climate stations have reported overnight lows in the 70s F this week. That is about 6-10 degrees F above normal. National Weather Service outlooks continue to favor warmer than normal temperatures across the state through the third week of July. The outlooks also favor, for the first time in many months, drier than normal conditions for the remainder of the month. This means of course that watering will be important.

Watering Considerations:


Since the climate outlooks favoring a warm and dry pattern for the remainder of July, it is important to remember some water conservation tips from the U of MN Extension:

-water plants and gardens at night or very early in the morning to minimize evaporation losses.

-use a light coating of mulch around some plants to minimize water loss from the soil, and to suppress weed competition.

-adjust your lawn mower to a higher setting as the longer grass keeps root systems shaded. During a warm July, lawns will need 1-2 inches of water per week.

-direct downspouts and other runoff towards shrubs, hedges and trees that can utilize the water.

-try to water at a rate that matches the infiltration rate of your soil....perhaps with a soaker hose.

-for newly planted trees and shrubs (planted this spring or summer) water thoroughly at least once per week all summer.

Weekly Weather Potpourri:


NOAA recently announced intentions to upgrade the Tropical Pacific Observing System (buoy platforms with instrumentation) by 2020 in partnership with Australia, China, and Japan. This observing network transmits data by satellite routinely and these data are used to assess El Nino signals, as well as to help with tropical storm forecasting in the Pacific Ocean Basin.


This week brought a tropical storm and some unprecedented heavy rains to southwestern Japan, the island of Kyushu (reported by the Kydo News Service). At times rainfall rates reached 4 inches per hour. Some places reported rainfall totals over 20 inches. Many roads and bridges were washed out and over half a million people were evacuated because of threatening flash floods.


At the end of last week the United Kingdom MetOffice put out a summary of June climate that showed the month to be very warm and wet. It was near record-setting wet in parts of Scotland and northern England, and also near record warm in eastern England.


Dr. Ben Santer of the Lawrence Livermore Laboratory in California wrote a very good piece on climate science and climate change for the Washington Post this week. It is well worth reading about the importance of staying engaged on this topic and finding ways for the USA to live up to the Paris Climate Agreement.


A recent paper in the Journal of Geophysical Research documents how the turbulence embedded in thunderstorms is linked to the lightning produced by such storms. It is the first of its kind to establish this link.

MPR listener question:


Now that we have the hottest part of the summer season upon us, we were wondering which part of the state has recorded the most 100 degree F days in history? Thought you might have the answer.

Answer:


Indeed, using the climate records back to the 1880s, the clear winner is west-central Minnesota, near the junction of Traverse and Big Stone Counties. The combined Beardsley and Browns Valley records show that 287 days have reached 100 degrees F or warmer since 1880, the most recent date being July 3, 2012. Other long-term climate states with large numbers of 100 degrees F days include Canby (Yellow Medicine County) with 198 and Milan (Chippewa County) with 161. These climate stations far surpass even the Twin Cities "heat island" climate record for 100 degrees F days, which shows a total of 65 back to 1872.

There are many climate stations in Minnesota that have never recorded a 100 degrees F reading, including Gunflint Lake (Cook County), Crane Lake (St Louis County), Two Harbors (Lake County), and Waskish (Beltrami County).

Twin Cities Almanac for July 7th:


The average MSP high temperature for this date is 84 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 64 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for July 7th:


MSP records for this date include: highest daily maximum temperature of 101 degrees F in 1936; lowest daily maximum temperature of 65 degrees F in 1918; lowest daily minimum temperature of 44 degrees F in 1891; highest daily minimum temperature of 80 degrees F in 1936; record precipitation of 3.00 inches in 1955. No snowfall has occurred on this date.

Average dew point for July 7th is 61°F; the maximum dew point on this date is 79°F in 1957; and the minimum dew point on this date is 38°F in 1934.

All-time state records for July 7th:


The all-time state high temperature for today's date is 108 degrees F at Browns Valley (Traverse County) in 1988; the all-time state low for today's date is 24 degrees F at Tower (St Louis County) in 1997. The all-time state record precipitation for this date is 5.00 inches at Elgin (Olmsted County) in 1990. No snow has fallen on this date.

Past Weather Features:


Temperatures fell into the upper 20s F to low 30s F across northern Minnesota on July 7, 1871. It was just 26 degrees F at Fort Ripley (Crow Wing County).

The hottest July 7th in state history occurred during the Heat Wave of 1936 (July 6-18). Over 50 communities reported daytime highs of 100 degrees F or greater. Some climate stations never saw the temperature drop below 80 degrees F even at night.

A strong thunderstorm gave birth to an EF-4 tornado (winds over 200 mph) on July 7, 1955. Between 4pm and 4:30 pm this storm moved 20 miles across portions of Lincoln and Lyon Counties in southwestern Minnesota. The tornado killed one person and damaged or destroyed 35 farms.

Strong thunderstorms brought heavy rains and hail to portions of northern Minnesota over July 7-8, 1962. Many observers reported 2-4 inches of rain, and nearly 4.5 inches fell at Fosston where crop fields were underwater for two days.

Frost occurred in parts of northeastern Minnesota on the morning of July 7, 1997. An all-time July low temperature of 24 degrees F occurred at Tower, bringing an end to a 23 day growing season there (last frost on June 14), one of the shortest in state history!

Outlook:


Near normal temperatures over the weekend under mostly sunny skies. Increasing cloudiness later on Sunday with a chance for widely scattered showers and thunderstorms, carrying over into Monday. Somewhat warmer for Tuesday through Thursday, with a chance for showers later on Wednesday and into Thursday.




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