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Extension > Mark Seeley's WeatherTalk > July 2013

Friday, July 26, 2013

Roller coaster temperatures July 18-21

Roller coaster temperatures July 18-21

Thursday, July 18th brought very warm temperatures, oppressive dewpoints and high Heat Index Values (ranging from 98 F to 107 F) across southern Minnesota counties. Record tying and record setting warm overnight low temperatures were also noted by some observers including MSP Airport with 80 degrees F (tied 2011), and Thielman, Melrose, and Isle with 73 degrees F (new record warm lows). If you want to read more about some of the history of warm nights in the Twin Cities when the temperature does not fall below 80 degrees F the Minnesota State Climatology Office has posted a narrative on their web site.

Just 3-days after July 18th, on Sunday (July 21st), a cool, dry Canadian air mass brought some near-record setting low temperatures to northern Minnesota observers, with many readings in the low to mid 40s F. International Falls tied a record low on Sunday with 41 degrees F (matching 1947), while Crane Lake reported a new record low of 39 degrees F. Such remarkable swings in temperature values are more common in late summer than mid-summer in Minnesota. 

Unusual tornado on July 22nd

The NOAA-National Weather Service Grand Forks Office reported on an unusual tornado earlier this week that struck between Mahnomen and Zerkel (Mahnomen County). This storm was unusual in several aspects: firstly it struck between 1:50 AM and 2:30 AM on July 22nd (Monday), a very rare time of day for tornadoes in our region (less than 2 percent of all tornadoes occur at that time of day); second, wind speeds were estimated to range from 110-120 mph (EF-2 strength), unusually strong for an overnight storm; thirdly, the storm path was nearly 18 miles in length (though intermittently on the ground), a relatively long storm path for an overnight storm. Thankfully this tornado did not cause any deaths or injuries, but it did damage a home, a number of farm structures, along with some farm equipment. It also caused a good deal of tree damage, especially around Roy Lake. This was the 6th confirmed tornado of the year so far in Minnesota. You can read more about the 2013 tornado season in Minnesota at the MN State Climatology Office web site.

Thunderstorms on July 25th

Strong thunderstorms visited parts of the state on Thursday, July 25th and overnight into Friday. There were numerous reports of damaging winds, hail (0.25 to 1.50 inches in diameter), and heavy rainfalls in some northern and southeastern counties. Some observers reported near record or record-setting rainfall amounts for July 25th including 2.47 inches at Spring Valley, 2.23 inches at International Falls (a record amount), 2.11 inches at Lanesboro (a record amount), 1.94 inches at Flag Island, 1.87 inches at Babbitt (a record amount), 1.62 inches at Long Prairie, and 1.55 inches at Grand Meadow. Some farmers were disappointed to see the rain fall on fresh cut hay fields, and a few in Fillmore County reported hail damage to crops.

Preliminary July climate summary

July's mean temperature for most observers in Minnesota was near normal or warmer than normal. The middle part of the month was very warm with many observers reporting daytime temperatures in the 90s F. Extremes for the month ranged from 96 degrees F at Little Falls, Gaylord, and Forest Lake on the 18th to just 38 degrees F at Brimson (St Louis County) on July 2nd. Even low temperatures in the mid to high 30s F may occur this Saturday morning (July 27) in northeastern counties. Several observers reported dewpoints in the 70s F which pushed the daytime Heat Index Values from 95 F to 105 F on some days. The warm temperatures produced higher than normal Growing Degree Days which boosted crop development, allowing late planted fields to catch up in their growth, and most corn fields went through the silking and pollen shed phase of development during the 3rd and 4th week of the month.

Precipitation for July was high variable around the state. Many observers in southwestern Minnesota counties reported less than normal precipitation. But for many locations intense thunderstorms brought heavy rainfall and these places finished the month with above normal precipitation totals. In the north International Falls and Gunflint Lake reported nearly 7 inches, Grand Marais over 7 inches, and Tofte nearly 5 inches. In central counties a number of observers reported over 5 inches, while in the south Wells and Dundas reported over 6 inches. Soil moisture reserves were adequate to surplus in most places as the month wraps up.

Weekly Weather potpourri

Colleagues at the Midwest Regional Climate Center have collaborated to produce a nice feature on their web site, called "Weather on the Day You Were Born." You can find out what the weather was like on your birth date and print out a certificate verifying it. Of course this can likely be verified by your parents as well! If you are interested in this feature click here.

Tropical Storm Flossie in the Eastern Pacific Ocean is headed towards Hawaii. By early next week it is expected to bring some heavy rain, 45-55 mph winds, and 15-20 foot seas to the islands. Flossie is the 6th named storm of the Eastern Pacific Tropical Storm season. In the Atlantic Ocean the National Hurricane Center was also tracking Tropical Storm Dorian, not expected to approach the Bahamas until the middle of next week.

Drought has taken a strong grip on southwest China this month, drying up lakes and reservoirs and causing some water rationing in other others. The rice crop has been negatively affected and some farmers have had difficulty keeping livestock fed and watered. The Chinese Meteorological Service says that some areas of seen their driest month of July since 1961. You can read more here.

A recent paper by scientists from Oregon State University published in the journal Nature explains the dynamical mixing of ocean waters in the central Pacific Ocean and how the sea surface temperature fluctuations influence large scale atmospheric patterns. You can read more about their work here.

MPR listener question


With the cool temperatures expected for Saturday morning and some daytime highs forecasted to only reach the 60s F I was wondering what the coolest July daytime high has been for the Twin Cities area, and also on a statewide basis?
Answer: The coolest daytime high for July in the Twin Cities climate record (1872-2012) is 58 degrees F on July 4, 1967. It was completely cloudy that day, all day, and with a low cloud ceiling. Winds were from the north and it was definitely jacket weather. On a statewide basis the north shore along Lake Superior usually records the coldest temperatures in July. On July 2, 1950 Grand Marais reported a morning low of 36 degrees F and an afternoon high of 49 degrees F, more November-like temperatures, but occurring in July. That day was dominated by wind off the lake, low overcast and light rainfall, again a definite jacket day.

Roller coaster temperatures July 18-21

Roller coaster temperatures July 18-21

Thursday, July 18th brought very warm temperatures, oppressive dewpoints and high Heat Index Values (ranging from 98 F to 107 F) across southern Minnesota counties. Record tying and record setting warm overnight low temperatures were also noted by some observers including MSP Airport with 80 degrees F (tied 2011), and Thielman, Melrose, and Isle with 73 degrees F (new record warm lows). If you want to read more about some of the history of warm nights in the Twin Cities when the temperature does not fall below 80 degrees F the Minnesota State Climatology Office has posted a narrative on their web site.

Just 3-days after July 18th, on Sunday (July 21st), a cool, dry Canadian air mass brought some near-record setting low temperatures to northern Minnesota observers, with many readings in the low to mid 40s F. International Falls tied a record low on Sunday with 41 degrees F (matching 1947), while Crane Lake reported a new record low of 39 degrees F. Such remarkable swings in temperature values are more common in late summer than mid-summer in Minnesota. 

Unusual tornado on July 22nd

The NOAA-National Weather Service Grand Forks Office reported on an unusual tornado earlier this week that struck between Mahnomen and Zerkel (Mahnomen County). This storm was unusual in several aspects: firstly it struck between 1:50 AM and 2:30 AM on July 22nd (Monday), a very rare time of day for tornadoes in our region (less than 2 percent of all tornadoes occur at that time of day); second, wind speeds were estimated to range from 110-120 mph (EF-2 strength), unusually strong for an overnight storm; thirdly, the storm path was nearly 18 miles in length (though intermittently on the ground), a relatively long storm path for an overnight storm. Thankfully this tornado did not cause any deaths or injuries, but it did damage a home, a number of farm structures, along with some farm equipment. It also caused a good deal of tree damage, especially around Roy Lake. This was the 6th confirmed tornado of the year so far in Minnesota. You can read more about the 2013 tornado season in Minnesota at the MN State Climatology Office web site.

Thunderstorms on July 25th

Strong thunderstorms visited parts of the state on Thursday, July 25th and overnight into Friday. There were numerous reports of damaging winds, hail (0.25 to 1.50 inches in diameter), and heavy rainfalls in some northern and southeastern counties. Some observers reported near record or record-setting rainfall amounts for July 25th including 2.47 inches at Spring Valley, 2.23 inches at International Falls (a record amount), 2.11 inches at Lanesboro (a record amount), 1.94 inches at Flag Island, 1.87 inches at Babbitt (a record amount), 1.62 inches at Long Prairie, and 1.55 inches at Grand Meadow. Some farmers were disappointed to see the rain fall on fresh cut hay fields, and a few in Fillmore County reported hail damage to crops.

Preliminary July climate summary

July's mean temperature for most observers in Minnesota was near normal or warmer than normal. The middle part of the month was very warm with many observers reporting daytime temperatures in the 90s F. Extremes for the month ranged from 96 degrees F at Little Falls, Gaylord, and Forest Lake on the 18th to just 38 degrees F at Brimson (St Louis County) on July 2nd. Even low temperatures in the mid to high 30s F may occur this Saturday morning (July 27) in northeastern counties. Several observers reported dewpoints in the 70s F which pushed the daytime Heat Index Values from 95 F to 105 F on some days. The warm temperatures produced higher than normal Growing Degree Days which boosted crop development, allowing late planted fields to catch up in their growth, and most corn fields went through the silking and pollen shed phase of development during the 3rd and 4th week of the month.

Precipitation for July was high variable around the state. Many observers in southwestern Minnesota counties reported less than normal precipitation. But for many locations intense thunderstorms brought heavy rainfall and these places finished the month with above normal precipitation totals. In the north International Falls and Gunflint Lake reported nearly 7 inches, Grand Marais over 7 inches, and Tofte nearly 5 inches. In central counties a number of observers reported over 5 inches, while in the south Wells and Dundas reported over 6 inches. Soil moisture reserves were adequate to surplus in most places as the month wraps up.

Weekly Weather potpourri

Colleagues at the Midwest Regional Climate Center have collaborated to produce a nice feature on their web site, called "Weather on the Day You Were Born." You can find out what the weather was like on your birth date and print out a certificate verifying it. Of course this can likely be verified by your parents as well! If you are interested in this feature click here.

Tropical Storm Flossie in the Eastern Pacific Ocean is headed towards Hawaii. By early next week it is expected to bring some heavy rain, 45-55 mph winds, and 15-20 foot seas to the islands. Flossie is the 6th named storm of the Eastern Pacific Tropical Storm season. In the Atlantic Ocean the National Hurricane Center was also tracking Tropical Storm Dorian, not expected to approach the Bahamas until the middle of next week.

Drought has taken a strong grip on southwest China this month, drying up lakes and reservoirs and causing some water rationing in other others. The rice crop has been negatively affected and some farmers have had difficulty keeping livestock fed and watered. The Chinese Meteorological Service says that some areas of seen their driest month of July since 1961. You can read more here.

A recent paper by scientists from Oregon State University published in the journal Nature explains the dynamical mixing of ocean waters in the central Pacific Ocean and how the sea surface temperature fluctuations influence large scale atmospheric patterns. You can read more about their work here.

MPR listener question

With the cool temperatures expected for Saturday morning and some daytime highs forecasted to only reach the 60s F I was wondering what the coolest July daytime high has been for the Twin Cities area, and also on a statewide basis?

Answer: The coolest daytime high for July in the Twin Cities climate record (1872-2012) is 58 degrees F on July 4, 1967. It was completely cloudy that day, all day, and with a low cloud ceiling. Winds were from the north and it was definitely jacket weather. On a statewide basis the north shore along Lake Superior usually records the coldest temperatures in July. On July 2, 1950 Grand Marais reported a morning low of 36 degrees F and an afternoon high of 49 degrees F, more November-like temperatures, but occurring in July. That day was dominated by wind off the lake, low overcast and light rainfall, again a definite jacket day.

Twin Cities Almanac for July 26th


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 64 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for July 26th

MSP weather records for this date include: highest daily maximum temperature of 100 degrees F in 1894 and 1955; lowest daily maximum temperature of 68 degrees F in 1903 and 1972; lowest daily minimum temperature is 45 degrees F in 1962; highest daily minimum temperature of 76 F in 1931; and record precipitation of 2.44 inches in 1990; No snow has been recorded on this date.

Average dew point for July 26th is 60 degrees F, with a maximum of 77 degrees F in 2003 and a minimum of 37 degrees F in 1974.

All-time state records for July 26th

The state record high temperature for this date is 107 degrees F at Maple Plain (Hennepin County), Wheaton (Traverse County), and Beardsley (Big Stone County) in 1931. The state record low temperature for this date is 27 degrees F at Tower (St Louis County) in 1980 and at Kelliher (Beltrami County) in 2001. State record precipitation for this date is 5.24 inches at Rochester (Olmsted County) in 1949; and no snow has fallen on this date.

Past Weather Features:

July 26, 1931 was the hottest in history as 30 Minnesota cities reported daytime highs of 100 degrees F or greater. The Heat Wave lasted from the 24th to the 28th and caused crops to wilt and die in many fields, especially in western parts of the state. Overnight temperatures finally fell back into the 50s and 60s F on July 29th.

July 24-28, 1949 brought a very wet period, flooding many farmer's fields. Many areas of the state received several inches of rainfall, while Chaska and Rochester received over 5 inches. On a statewide basis it was the 3rd wettest July in history with most observers reporting over 6 inches of rainfall, and some reporting over 10 inches. In the wet fields some corn crops suffered from lodging, blown over by strong winds.

July 26, 1980 was one of the coldest in history up north with many observers reporting morning low temperatures in the 30s F and three communities reporting temperatures in the upper 20s F.

On July 26, 2000 the residents of Granite Falls, MN were cleaning up from an F-4 tornado (winds from 207-260 mph) the previous afternoon. The storm killed one person, injured 15, and caused nearly $20 million in damages, the worst such storm in the history of the city.

Outlook

Below normal temperatures over the weekend and early next week with a chance for widely scattered shower activity. Some overnight temperatures over the weekend may approach record lows. A warming trend will start during the middle of next week and bring temperatures back closer to normal. Chance for showers Tuesday and Wednesday.

Friday, July 19, 2013

Record Rainfall on July 13

Record Rainfall on July 13

For some Minnesota citizens the early morning hours (4 am to 8 am) on Saturday, July 13th were quite noisy, with thunder, high winds, and very heavy rainfall. The rainfall amounts ranged from 1 to 3 inches across many east-central counties, and were even higher in parts of Scott, Rice, Steele, and Waseca Counties. Some National Weather Service observers reported new daily record amounts for July 13th, including 3.80 inches at Wells, 3.02 inches at Chanhassen, 2.79 inches at MSP Airport, 2.75 inches at Rosemount, 2.44 inches at Brainerd, 2.30 inches at Faribault, 2.23 inches at Rockford, and 1.82 inches at Owatonna.

These rains caused the National Weather Service to issue a number of flood warnings for areas along the Vermillion, Straight, and Cannon Rivers, and flash flood warnings for many communities, including Wells, Faribault, Northfield, New Market, Dundas, and Shakopee. You can read more about this storm here.

Further, the Midwest Climate Center informs us that the first six months of 2013 (January-June) has been the wettest in history for Michigan (20.80" statewide average), Iowa (24.93" statewide average), Wisconsin (21.85" statewide average), and Illinois (29.11" statewide average). In Minnesota it has been the 3rd wettest first six months of the year averaging 16.93 inches statewide (this trails only 17.31 inches in 1908 and 17.83 inches in 1896). Harmony, MN (Fillmore County) has reported nearly 35 inches of precipitation so far this year and their annual normal is 34.63 inches!

Record rainfall in NE MN on July 18-19

Late in the day on Thursday, July 18th and overnight into Friday, July 19th strong thunderstorms trained over far northeastern Minnesota bringing damaging winds, hail, and intense rainfall. Flood warnings had to be issued by the National Weather Service for a number of rivers, as well as for the city of Grand Marais. Among the observers reporting record amounts of rainfall were International Falls with 2.15 inches, Kabetogama with 1.63 inches, Gunflint Lake with 3.23 inches, and Grand Marais with 3.53 inches. The amount of rainfall at Grand Marais was the 5th highest 24-hour total ever measured there.

July Heat

Tuesday, July 16 through Thursday, July 18 brought numerous 90 degrees F readings to southern Minnesota counties, and widespread Heat Advisories issued by the National Weather Service. Dew points were very high as well touching 70 degrees F or higher on 5 consecutive days and helping to push the Heat Index values near 100 F or higher. On Tuesday, July 16 at least 20 cooperative observers reported highs in the 90s F, Wednesday (July 17) that number jumped to 56 observers, and Thursday (July 18) at least 65 cooperative observers reported high temperatures of 90 degrees F or greater. Fortunately a cold front brought relief from the heat on Friday, and further relief was expected into the weekend.

 

Weekly Weather potpourri

A recent paper in the International Journal of Climatology documents how tropical storms can intensify even after they make landfall when the surrounding soil is wet enough to provide evaporative fuel (latent heat) for the storm. Under such conditions "the land essentially mimics the moisture-rich environment of the ocean, where the storm originated," says Theresa Andersen from the University of Georgia, one of the paper's co-authors. You can read more about this study of tropical storms here.

This week NASA's Earth Observatory is showing images of the melt season on the Greenland ice sheet as the ponds forming across the ice have accelerated in recent days. The melt season did not start as early as it did in 2012, nor is it expected to be as intense, but it is still on a faster pace than average for the period from 1981-2010. You can see more and read more about this here.

MPR listener question

As a life long resident of the Twin Cities I wondered if there is a day of the year that has seen significantly less frequency of precipitation than any other day of the year. If so, what day is it?

Answer: That is an interesting question I had never considered. Our State Climatology Office examined the Twin Cities climate record back to 1871 (142 years) and found that February 8th has brought precipitation the fewest number of times (17 percent) just 24 days, while November 6 is a close second with (18 percent) just 26 days. The day of the year which has recorded the highest precipitation frequency is June 14 with 48 percent, or 68 days.

As a sidebar to this answer the State Climatologist in California informs me that June 21st has never brought a rain to Fresno (133 years of record), and that July 7th has never brought a rain to San Francisco (164 years).

 

Twin Cities Almanac for July 19th

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 6 degrees F standard deviation).

MSP Local Records for July 19th

MSP weather records for this date include: highest daily maximum temperature of 100 degrees F in 1940 and 1977; lowest daily maximum temperature of 63 degrees F in 1877 and 1902; lowest daily minimum temperature of 46 F in 1873; highest daily minimum temperature of 79 F in 1977; and record precipitation of 1.75 inches in 1957; No snow has been recorded on this date.

Average dew point for July 19th is 61 degrees F, with a maximum of 82 degrees F in 2011 and a minimum of 41 degrees F in 1958.

All-time state records for July 19th

The state record high temperature for this date is 108 degrees F at Canby (Yellow Medicine County) in 1932 and at Redwood Falls (Redwood County) in 1934. The state record low temperature for this date is 29 degrees F at Tower (St Louis County) in 2000. State record precipitation for this date is 8.97 inches at Fosston (Polk County) in 1909; and no snow has fallen on this date.

Past Weather Features:

Strong thunderstorms in northern Minnesota brought flash flooding to some areas over July 19-20, 1909. Bagley and Beaulieu reported over 10 inches of rain, while Fosston reported 9 inches and Walker 6 inches. In some areas the small grain harvest was delayed because of wet ground.

On July 19, 1912 ground frost was reported at a number of northern Minnesota locations, including Bagley, Roseau, Pokegama Dam, Cloquet, Virginia, and Littlefork. Overnight lows were in the low to mid 30s F, while daytime highs were in the 60s and 70s F during the week.

July 19th brought high temperatures of 100 degrees F or greater to parts of Minnesota in 1926, 1932, and 1934. In 1926 a 7-day Heat Wave prevailed in southern MN bringing 90 plus F temperatures each day over July 15-21. In 1932 an 11-day Heat Wave prevailed over July 12-22. In 1934 a Heat Wave began on July 19th and lasted until the 27th, bringing consecutive days with 100 degrees F or greater to many western and southern Minnesota communities.

July 17-21, 1999 was extremely wet in southern Minnesota counties with daily thunderstorms and large rainfalls. Austin, Preston, Spring Grove, Hokah, Winnebago, Wells, Harmony, and Albert Lea all reported 5 to 6 inches of rainfall. Grand Meadow reported nearly 8 inches. July of 1999 was the wettest in history for southeastern counties with total monthly rainfall averaging nearly 9 inches among all observers.

Some of the highest Heat Index values ever measured in our region occurred on July 19, 2011. Temperatures were primarily in the 90s F with dewpoints in the 80s F. Some of the more remarkable Heat Index readings that day included: 107 F at Montevideo, 110 F at Morris, 111 F at Fergus Falls, 112 F at Olivia and Appleton, 113 F at Redwood Falls, 114 F at New Ulm, 115 F at Marshall and Ortonville, 116 F at Fargo, ND, 117 F at Willmar, St Cloud, and Benson, 119 F at MSP, and 130 F at Moorhead. These were the warmest spots in North America that day.

Outlook

Cooler and less humid over the weekend, with daytime temperatures falling back into the 70s and 80s F. Chance of widely scattered showers late in the day on Saturday and Sunday. Warmer by the middle of next week.

Friday, July 12, 2013

First significant rain of the month

First significant rain of the month

July 9th (Tuesday) brought thunderstorms to Minnesota and the first significant rainfall of the month for many. Several observers in northern, east-central, and southeastern Minnesota reported amounts ranging from 0.50 inches to over 1 inch. Some of the larger amounts included 1.11 inches at Hallock, 1.72 inches at Waskish, 1.25 inches at Montevideo, 1.07 inches at Gaylord, and 1.00 inches at Vesta. Yet more rainfall is expected over the weekend and into next week, coming at a key time for the state's rapidly growing corn and soybean crops, and newly seeded alfalfa fields.

Comparing the Twin Cities Heat Waves of 1936 and 1995

The two hottest July 12th dates in Minnesota state history occurred in 1936 and 1995. They were both associated with multi-day Heat Waves, but there was a distinctive difference in their character. In 1936, a serious drought had a grip on the state too, as the month of July brought only 0.11 inches of rainfall following a dry spring. The core period for the Heat Wave was 13 days long, from the 6th to the 19th. Daytime highs were 95 degrees F or greater each day, peaking at 108 degrees F on the 14th. On 7 consecutive nights (the 7th to the 13th) the overnight lows never dropped below 80 degrees, peaking with a low of 86 degrees F on the 13th. Without air conditioning many Twin Cities residents slept on screen porches, in city parks, or along lake shorelines. Dew points ranged from the upper 50s to mid 60s F, not high enough to inflate the Heat Index (combination of temperature and humidity). Nevertheless the persistent heat caused approximately 180 deaths in the Twin Cities (estimated by the coroners of Hennepin and Ramsey Counties), with the peak loss of life on July 13 and 14. Statewide, officials estimated 759 lives lost due to the Heat Wave, the most in Minnesota history. By the end of the month wildfires plagued the northern counties and navigation was suspended on the Mississippi River due to very low flow volume. More modest heat prevailed the rest of the month, resulting in the hottest month of July in Minnesota's history.

The Heat Wave in 1995 lasted from July 11 to 14 and was primarily the result of unusually high dewpoints (some observers reported 80 degrees F DP values) which inflated the Heat Index. Heat Index values over the four days ranged from 97 degrees F to 115 degrees F, while the daytime maximum temperatures ranged from 90 degrees F to 101 degrees F. The overnight low on the 12th never dropped below 80 degrees F. This Heat Wave did not produce high mortality in the Twin Cities, but did contribute to nearly 500 deaths in Chicago, IL. The Minnesota Heat Wave did produce high turkey loss in central Minnesota as hundreds of thousands of birds died, and some pregnant dairy cows aborted as a result of the heat stress. Thankfully after the 15th of the month air temperatures moderated in the 80s F during the day and 60s F at night for most of the balance of the month.

Weekly Weather potpourri

Last month (June, 2013) the International Journal of Climatology published an excellent and comprehensive review article title "Land cover changes and biogeophysical effects on climate." This was written by several well know climate scientists and presents a great deal of evidence for the size and magnitude of climate change brought on by land cover changes. It is a good read in helping us understand how climate change is proceeding at a different pace in different places. You can read the paper online.

The Minnesota State Climatology Office has done a mid-season compilation of 2013 severe weather. So far only 5 tornadoes have been confirmed in the state, but we have seen plenty of heavy rains, high winds and hail associated with thunderstorms. A synopsis of the season can be found at the web site.

Monday afternoon and evening (July 8th) brought heavy thunderstorms to parts of Ontario, Canada. Toronto saw record-setting rainfall amounts exceeding 4 inches in 4 hours in some areas . This caused flash flooding closing down bus and train commuter services and overflowing the capacity of the city storm sewer system. There were also several power outages in the area. Media reported many road closures and reports of basements flooding. More information is available here.

Powerful Typhoon Soulik in the Western Pacific Ocean was heading for the island nation of Taiwan as the weekend approached. Typhoon Soulik packed winds from 110-130 mph, producing wave heights of over 40 feet. It was expected to weaken and dissipate over the weekend as it made landfall in China, bringing heavy rains to coastal areas.

On Wednesday this week (July 10th) the National Park Service and the NOAA National Weather Service hosted a 100th Anniversary celebration at the Furnace Creek Visitor's Center in Death Valley, CA in honor of the planet Earth's warmest temperature ever measured, 134 degrees F on July 10, 1913. The celebration took place during the day with temperatures ranging from 112 degrees F to 117 degrees F after an overnight low of 94 degrees F. I did not hear an estimate of attendance there.  Read more here.

MPR listener question

I riding the MS TRAM from International Falls, MN to Duluth, MN next week (July 15-19). What kind of weather do you think we'll encounter?

Answer: I see this year's TRAM has stops in Orr, Chisholm, Biwabik, and Two Harbors before arriving in Duluth on Friday, July 19th. It appears the weather each day will bring near normal temperatures (upper 70s to low 80s F during the day and upper 50s to low 60s F at night), but each day will have a chance for showers and thunderstorms. So I would recommend taking some rain gear just in case.

Twin Cities Almanac for July 12th

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 64 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for July 12th

MSP weather records for this date include: highest daily maximum temperature of 106 degrees F in 1936; lowest daily maximum temperature of 67 degrees F in 1926; lowest daily minimum temperature of 48 F in 1941; highest daily minimum temperature of 83 F in 1936; and record precipitation of 2.93 inches in 1912; No snow has been recorded on this date.

Average dew point for July 12th is 61 degrees F, with a maximum of 80 degrees F in 1995 and a minimum of 39 degrees F in 1926.

All-time state records for July 12th

The state record high temperature for this date is 111 degrees F at Canby (Yellow Medicine County) in 1936. The state record low temperature for this date is 27 degrees F at Tower (St Louis County) in 1975. State record precipitation for this date is 5.45 inches at Buffalo (Wright County) in 1961; and no snow has fallen on this date. 

Past Weather Features:

Mid-July frosts though rare in Minnesota have occurred even in the vicinity of the Twin Cities. On the mornings of July 11-14, 1863 many residents in and around the Twin Cities reported damaging frost as temperatures dropped into the 30s F. Corn, potatoes, pumpkins, cucumbers, and tomatoes were all reported to be "seriously damaged' by the frosts. Later in the month wildfires caused the air to be smoke filled on many days as well. So all in all it was a rather disagreeable month.

Thunderstorms brought heavy rain, hail, and strong winds to parts of west central and south central Minnesota over July 11-12, 1972. Wind gusts were reported to range from 55 mph to 80 mph, damaging farm buildings and knocking down trees. Heaviest rainfall amounts ranged from 4 to 7 inches over an area from Fergus Falls southeast to Melrose. Many roads and ditches flooded. Farmers reported moderate crop damage from hail, and some cattle were killed by lightning strikes in Redwood County.

July 12, 1975 was one of the coldest in state history, with some ground frost reported in northeastern Minnesota where morning minimum temperatures ranged from the upper 20s to mid 30s F. A dry, cool Canadian air mass descended on the state and even kept daytime highs in the 60s F (20-25 degrees F cooler than average). The high at Babbitt was only 66 degrees F, Grand Marais was 63 degrees F, and both Tower and Two Harbors topped out at just 62 degrees F as Mother Nature's air conditioning system brought a respite from the normal July heat. Tower was back in the 90s F by the 16th.

mPING

This acronym stands for Meteorological Phenomena Identification Near the Ground, a mobile app and computer data base that is a combined effort of the NOAA-National Severe Storms Lab, University of Oklahoma, and Cooperative Institute for Mesoscale Meteorological Studies. The mPING app provides a mechanism for filing a report on severe or unusual weather that automatically enters the database with notation about place and time. Both past and real-time reports across the nation can be viewed using the web site.

This system is used to verify severe or hazardous weather reports and radar interpretations of weather. The App can be found at Itunes or Google Play. You can read about it here.

Outlook

Warmer than normal temperatures across southern Minnesota into the weekend with a chance for widely scattered showers and thunderstorms. Near normal temperatures in northern areas with a better chance for showers and thunderstorms. Warm temperatures will prevail in central and southern counties well into next week with higher dewpoints producing some Heat Index values near 100 degrees F. There will be continued chances for showers and thunderstorms much of next week as well.

Friday, July 5, 2013

Best days of the summer this week

Best days of the summer this week

Weatherwise, we are experiencing perhaps one of the best starts to July in recent years. Low temperatures have been in the 50s and 60s F with daytime highs in the upper 70s to low 80s F and plenty of sunshine. Little rainfall so far this month following a generally wet June and wet spring. Thankfully dewpoints have remained in the comfortable 50s F providing near perfect weather for outdoor activities. Even at Embarrass, MN overnight lows have not dropped below 41 degrees F, while daytime highs have risen to 82 degrees F.

The July 4th weekend will bring some warmer than normal temperatures that will linger through Monday. On July 4th MSP, Wheaton, Fergus Falls, Browns Valley, Montevideo, Milan, Wheaton, Moorhead, and Ortonville all reached 90 degrees F. This marked the 22nd time the Twin Cities has recorded at least 90 degrees F on Independence Day since 1871.

New ice-in data set for Minnesota lakes

The DNR-State Climatology Office has developed a web-based climatology for ice-in dates on Minnesota lakes to match the popular and widely utilized ice-out data set that has been in play for years. The period of record varies by lake but users can look at average dates in the fall when lakes freeze up, as well as what the historical extreme dates (early and late) have been. For access and further information you can go to the web site.

Global Upper Air Stations

Under the jurisdiction of the World Meteorological Organization (WMO) and the Global Observing Systems Information Center (GCOS) a worldwide network of upper air observations provides government weather services and the atmospheric and climate science research communities with profile measurements (temp, dewpoint, pressure, wind speed and direction) of the Earth's atmosphere. Many of these measurements are done on a 12 hourly basis to initialize numerical forecast models. The instrumented balloons, called radiosondes, are launched from a variety of land-based and ship-based stations. The Twin Cities radiosonde data are depicted graphically at the following web site.

The WMO has a list of over 1700 such stations worldwide, with most of them located in the countries of the northern hemisphere. There is great disparity in data coverage, with North America and Europe having a relatively large number of radiosondes launched each day, and Africa having very few. There is a good article on the NOAA web site this week highlighting the value of these measurement systems, both in weather forecasting and in atmospheric research. You can find it here.

 

Weekly Weather potpourri

Weatherwise magazine features an article by Sean Potter about July, 1776 in Philadelphia, PA where Thomas Jefferson was taking part in deliberations that eventually produced the Declaration of Independence. During that month he kept daily weather records and observers. It was somewhat hot and humid outside and even more stifling in the chamber where the 2nd Continental Congress was meeting. You can read more about this article here.

Hurricane Dalila was churning in the Eastern Pacific Ocean southwest of Puerto Vallarta, Mexico this week. It was expected to slowly dissipate out to sea and not be a threat to Mexico. Maximum winds were ranging from 85 to 95 mph producing sea wave heights of 30-35 feet. Tropical Storm Erick was spinning off the west coast of Mexico further south. It was expected to strengthen over the weekend.
For southeastern Minnesota crop producers many acres remain unplanted due to the wet spring conditions. Weeds are prolific and large in these fields and pose a long term concern due to the amount of their seed production. According to Dr. Jeff Gunsolus, weed specialist with Extension control of these weeds by mowing or tillage would be a good strategy to deploy at this time. You can read more on this topic in the Crop Newsletter.

Well-known Japanese water scientist Masaru Emoto will be in the Twin Cities to give two programs this month on the unique properties of water relative to wave and sound. You can read more about him and these events at the following web site:

http://www.masaru-emoto.net/english/index.html

MPR listener question

Having started July so sunny and dry here in the Twin Cities we were wondering what the monthly rainfall extremes are for the month? Also what is the historical range in the number of rainy days during the month?

Answer: For the Twin Cities climate record, 1871-2012, the driest July was in 1894 when only 0.20 inches of rain fell. The wettest was in 1987 when 17.90 inches fell (10 inches fell on July 23rd in six hours that year). The fewest days with rain occurred in 1895 with just 3 days, while the most rainy days were recorded in 1972 and 1987 with 16 days.

Twin Cities Almanac for July 5th

The average MSP high temperature for this date is 83 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 62 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for July 5th

MSP weather records for this date include: highest daily maximum temperature of 100 degrees F in 1982; lowest daily maximum temperature of 66 degrees F in 1905; lowest daily minimum temperature of 45 F in 1967 and 1972; highest daily minimum temperature of 78 F in 1982; and record precipitation of 1.62 inches in 1994; No snow has been recorded on this date.

Average dew point for July 5th is 59 degrees F, with a maximum of 77 degrees F in 1949 and a minimum of 40 degrees F in 1972.

All-time state records for July 5th

The state record high temperature for this date is 108 degrees F at Pipestone (Pipestone County) in 1936. The state record low temperature for this date is 27 degrees F at Tower and Embarrass (St Louis County) in 2001. State record precipitation for this date is 6.25 inches at Albert Lea (Freeborn County) in 1943; and no snow has fallen on this date.

Past Weather Features:

Baseball size hailstones fell overnight on July 5, 1966 at Detroit Lakes (Becker), MN. These were some of the largest hailstones every observed in the area, one was nearly a foot in circumference. Strong winds up to 48 mph damaged some buildings in the area and thunderstorms brought nearly 2 inches of rain.

July 5-6, 1978 brought heavy thunderstorms to southeast Minnesota from Dodge to Winona Counties. The heaviest band of 6-7" occurred just south and east of the Rochester area. The Zumbro River and it's tributaries (Bear Creek, Silver Creek, Cascade Creek) went into flood through Rochester causing extensive damage. The July 6 crest at the Rochester river gage established an all-time record of 23.36 ft and 30,500 cfs. This flood and yet another in September prompted the construction of a major flood control project by the U.S. Army Corps of Engineers and the Natural Resources Conservation Service in and around Rochester. The project was completed in 1995, at a cost amounting to $92 million and protects the city against a 200-year recurrence interval flood event.

July 5, 1988 was arguably the warmest in state history with nearly every observer in the state reporting a daytime high in the 90s F. Even International Falls reached a high of 96 degrees that day. Over 20 communities reported afternoon temperatures of 100 degrees F or higher.

July 4-5, 1999 brought a destructive "derecho" to northern counties, especially across the BWCA where millions of trees were blown down by 70-90 mph straight-line winds. Heavy thunderstorms brought 4 to 8 inches of rainfall to parts of St Louis, Lake, and Cook Counties. Some roads were closed for a time due to flooding and washouts. The Hibbing Airport reported 7.81 inches of rainfall, a record amount there.

July 5, 2001 brought a rare July frost to northern Minnesota communities. Hibbing, Embarrass, Tower, Brimson, and Kelliher, reported morning low temperatures that ranged from 27 to 32 degrees F. After starting the day at 28 degrees F Kelliher warmed all the way up to 73 degrees F by mid-afternoon.

Outlook

Partly cloudy over the weekend with warmer than normal daily temperatures. Dew points will slowly creep into the 70s F in some southern counties making for some uncomfortable days. Chance for scattered showers and thunderstorms each day through Wednesday, then drier and cooler towards the end of the week. 
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