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Extension > Mark Seeley's WeatherTalk > August 2013

Friday, August 30, 2013

Meet and Greet at the State Fair

Meet and Greet at the State Fair

For those who would like to visit about the weather I will be at the University of Minnesota CFANS Alumni Lounge in the Agriculture/Horticulture Building on the State Fairgrounds this Saturday from 4:00 to 5:00 pm. If you plan to attend the State Fair on Saturday, please drop by and say hello.

August Heat Wave

According to the Mayo Clinic when the Heat Index reaches 91 degrees F or higher, people should take precautions to avoid heat exhaustion, especially young people, elderly people, or those suffering from certain chronic illness (COPD, MS, etc) that require medications. This is the reason the National Weather Service issues heat advisories (Heat Index values in the 90s F to 100 F) and excessive heat warnings (Heat Index Values above 100 F), with other modifiers to take into account how little overnight cooling occurs.

The longest Heat Wave of 2013 occurred this week in southern Minnesota, starting mid-afternoon on Saturday (Aug 24) with a Heat Index of 96 degrees F in the Twin Cities and continuing through Thursday evening (Aug 29). Many high temperature records were set around the state for both daytime maximum values and nighttime minimum values. MSP reported overnight low temperatures from the 25th to the 27th of 80 F, 80 F, and 79 F. The 80 F readings were only the 5th and 6th occurrences of such high minimum temperatures in the history of August back to 1872.

Reported Heat Index Values from MSP included: Sat (Aug 24) 96 F; Sun (Aug 25) 105 F; Mon (Aug 26) 106 F; Tue (Aug 27) 107 F; Wed (Aug 28) 92 F; Thursday (Aug 29) 100 F

In addition, on Tuesday August 27th the dewpoint reached a daily record tying value of 77 degrees F, also tying the mark for the highest value measured during a run of the State Fair (tied August 28, 1955 and August 27, 1990). Perhaps more importantly, the Heat Index values in the Twin Cities from 3:00 pm on Saturday (Aug 24) to 11:00 pm on Wednesday (Aug 28) rarely fell below 83 degrees F during any given hour. Thus the persistence of heat lasted well over 100 consecutive hours. This was problematic for the opening of the school year in many school districts, especially those buildings without air conditioning, and for Minnesota State Fair goers and workers who had to worry about staying hydrated in such stressful conditions.

Keeping children hydrated and attentive for school classroom and playground activities was a challenge, not just in Minnesota but in Iowa and Nebraska as well. Many schools took precautions to avoid any health risks to their students, such as giving them more breaks, shortening recess activities or athletic activities, and taking water breaks. In the end, some school districts simply cancelled school later in the week, a smart choice and somewhat analogous to school cancellations that have occurred historically for extreme cold in the winter season (when Wind Chill Index values have ranged below -35 F), a more well known health risk to school aged children. Perhaps modifying schools to make them useful even on warm days is a good idea as our climate behavior continues to change bringing more frequent and extreme warm spells.

The high of 92 degrees F on Thursday (Aug 29) marked the 6th day with daytime highs of 90 F or greater during the run of the 2013 Minnesota State Fair, surpassing the record of 5 days with 90 F or higher that occurred in 1922, 1931, 1960, and 1991. Undoubtedly the 2013 State Fair will go down as the warmest or one of the warmest in history (back to 1885). With a possibility of 90 F or higher again on Friday (Aug 30)or Saturday (Aug 31), then the new State Fair record for 90 F days may go to seven.

Preliminary August Climate Summary

As August wraps up this Saturday, a look back reveals a highly variable month climatically. Average temperatures for August will end up ranging from 1 to 4 degrees F above normal for most observers. The month started cooler than normal through the first half of the month, with relatively low dewpoints, then above normal temperatures, record-setting in some cases took over for the rest of the month. Extremes for the month ranged from 98 degrees F at Forest Lake on the 27th to just 31 degrees F at Embarrass on the 14th. Browns Valley set a new record low on the 14th as well with a reading of 39 degrees F. Conversely, over the period from August 20-27 as many as 30 new daily maximum temperature records were set around the state, along with 67 new daily warm minimum temperatures. The above normal temperatures help crops "catch up" a bit and move more rapidly toward maturity.

Moisture wise, the month of August was generally dry, but highly variable too. With few exceptions Minnesota observers are reporting a drier than normal month of August. Driest areas were in northwestern counties, some central counties, and the far northeast (Cook County) where total monthly precipitation was less than 1 inch. Only a handful of reported monthly rainfall totals over 3 inches. Some of the higher amounts in the state included: 4.20 inches at Windom and Albert Lea, 3.77 inches at St James, and 3.71 inches at Blue Earth. Thunderstorms brought record-setting daily rainfall at 9 locations on the 5th of the month including 1.95 inches at Wells, 1.62 inches at Winnebago, and 1.42 inches at Milan. Again on the 11th a strong thunderstorm brought a record 2.11 inches to Windom.

The drier than normal August follows a drier than normal July which has produced a combined rainfall deficiency for the two months that ranges from 5 to 7 inches below normal in many areas. The consequence of this is a re-emergence of moderate drought in over half of the state's landscape. You can read more about this at our web site.

There were three noteworthy weather features in August. On the 6th a supercell thunderstorm brought high winds and large hail to many areas south of the I94 corridor. Many communities reported hail from 1.5 to 2.0 inches in diameter, with some crop damage. Three inch diameter hail was reported in parts of Kandiyohi County. In addition winds up to 60 mph damaged trees in Dakota, Wilkin, and Hennepin Counties.

About 8:15 pm on Tuesday, August 27 a tornado, the 7th of the season for Minnesota, touched down briefly northwest of Wadena, MN near the intersection of highways 10 and 75. No serious damage was reported. And finally on Thursday, August 29th, strong thunderstorms brought hail and damaging winds to portions of northeastern Minnesota, including a measured wind of 68 mph near Castle Danger along the north shore of Lake Superior. Further the 8th Minnesota tornado of 2013 was spotted between Remer and Hill City, fortunately with little damage associated.

Climate Change Adaptation Conference at the Science Museum on November 7, 2013

Several organizations are partnering to host the first statewide conference on Climate Change Adaptation, Planning and Practice. It will take place at the Science Museum of Minnesota in downtown St Paul on November 7, 2013. Registration for the all day program is only $50. Sessions will be devoted to city planning, agriculture, transportation, natural resources (including watershed management), and public health.

Weekly Weather potpourri

The RIM fire around Yosemite Valley in California has burned for nearly two weeks, charring more than 200,000 acres and costing nearly $40 million to fight (ranking among California's worst fires historically). Smoke from the fire made the air quality around Lake Tahoe very poor for many days. Though Mother Nature has not brought rain to help contain the fire, cooler temperatures are expected over the Labor Day weekend which will assist firefighters in making better progress in cutting fire breaks.

In the Western Pacific Ocean Tropical Storm Kong-Rey was expected to bring heavy rains to Japan over the weekend, and in the Eastern Pacific Ocean Tropical Storm Juliette was dissipating, though bringing the threat of rain to portions of Baja California as well.

Comments from the Brad Rippey of the USDA-Office of the Chief Economist during the drought briefing this week include:
Highlights for the drought-monitoring period ending 7 am EDT on August 27 include:
-Overall U.S. moderate to exceptional (D1 to D4) drought coverage increased more than four percentage points (up 4.43 points) to 50.04%. It was the first time that drought covered more than half of the contiguous U.S. since April 9, 2013. Hot, dry weather in the western Corn Belt led to sharp increases in drought coverage. According to the U.S. Drought Monitor, drought coverage in the nine-state Midwestern region increased from 8 to 25% during the week ending August 27. Coverage increased from 35 to 60% in Iowa; 10 to 55% in Minnesota; 15 to 31% in Missouri; 2 to 21% in Wisconsin; and 0 to 21% in Illinois. The portion of the U.S. corn production area in drought surged from 25 to 45% during the week ending August 27. Soybeans in drought also increased sharply in the last week, from 16 to 38%. Corn and soybeans in drought bottomed out last month at 17 and 8%, respectively. 

MPR listener question

With the late August run of 90 F days in the Twin Cities I wondered how common it is to have more such days in August than any other month of the year? Also, how frequently does August bring zero 90 F days?

Answer: Over the Twin Cities climate record since 1872 (142 years), there have been only 25 years (18 percent) when the month of August brought the most 90 F days. This year August and July are tied with each bringing 7 days of at least 90 F high temperatures. Coincidentally there have been only 25 years (18 percent) when August brought zero 90 F days as well, the most recent was 2011.

Twin Cities Almanac for August 30th

The average MSP high temperature for this date is 77 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 58 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for August 30th

MSP weather records for this date include: highest daily maximum temperature of 96 degrees F in 1941; lowest daily maximum temperature of 60 degrees F in 1965; lowest daily minimum temperature is 45 degrees F in 1935 and 1974; highest daily minimum temperature of 77 F in 2010; and record precipitation of 7.28 inches in 1977; No snow has been recorded on this date.

Average dew point for August 30th is 58 degrees F, with a maximum of 75 degrees F in 1951 and a minimum of 34 degrees F in 1931.

All-time state records for August 30th

The state record high temperature for this date is 103 degrees F at Minnesota (Lyon County) in 1976. The state record low temperature for this date is 26 degrees F at Sawbill Camp (Cook County) in 1935. State record precipitation for this date is 7.28 inches at the MSP airport in 1977; and no snow has fallen on this date.

Past Weather Features:

Strong thunderstorms brought flooding rains to parts of Minnesota over August 29-30, 1902. Many areas reported over 2 inches, while Lake Winnie, Pipestone, and Faribault received well over 3 inches. Farm fields in Wabasha County were flooded as over 5 inches of rain fell there.

August of 1921 ended with a heat wave across southern and western Minnesota, as over 20 communities reported temperatures from 90 to 100 degrees F. The heat wave last from August 28th to September 2nd and rapidly dried out crops. Temperatures dropped off into the 40s and 50s F by the second week of September.

Widespread and damaging frost occurred on perhaps the coldest August 30 in state history, that of 1931. Temperatures in the low 30s prevailed nearly statewide with a reading of just 33 degrees F as far south as Rochester and Zumbrota. Farmers reported frost damage to potatoes, corn, and garden vegetables, virtually ending the growing season.

On the evening of August 30, 1977 dark clouds appeared on the horizon. An intense thunderstorm began about 8:30 pm and brought 4-5 inches of rainfall to the State Fairgrounds by midnight. The maximum rainfall rate occurred between 9:00 and 10:00 pm with over 2.5 inches falling. The storm total of 7.36 inches at the MSP airport remains the 2nd greatest in Twin Cities history, surpassed only by the 10 inches that fell on July 23-24 of 1987. Hundreds of homes in the Twin Cities reported water damage. Evening events, including the Grandstand Show at the State Fair were cancelled.

Outlook

Diminishing temperatures and humidity over the weekend, with a chance for showers on Saturday, mostly west and north. Continued cooler into the middle of next week as temperatures fall back closer to normal. Dry conditions will prevail much of next week as well.

Friday, August 16, 2013

Cooler than normal temperature pattern continues

Cooler than normal temperature pattern continues

Over the past three weeks cooler than normal temperatures have dominated our region quite consistently. In fact International Falls, MN has reported 28 consecutive days with cooler than normal temperature readings. Some overnight lows have dipped to record setting values. On August 10th International Falls tied their record low of 38 degrees F. Then on Wednesday, August 14th several northern Minnesota communities reported record low values, including Ely (36 F), Orr (35 F), Crane Lake (34 F) Kabetogama (37 F), Grand Marais (32 F), Silver Bay (32 F) Brimson (30 F tied 2004), and International Falls again (35 F tied 1997). On Thursday (August 15) some additional low temperature records were set at Embarrass (32 F), Kabetogama (38 F), and Orr (35 F). Further, on Friday morning there were a few more reports of lows in the 30s F including Crane Lake and Orr (39 F) and Embarrass (36 F).

The cooler than normal temperature pattern will come to an end this weekend as a broad area of above normal temperatures settles over the Western Great Lakes region. It appears that the above normal temperature pattern may prevail for the rest of the month of August as well.

New Seasonal Climate Outlook

The NOAA-Climate Prediction Center released a new seasonal climate outlook on Thursday of this week. The outlook for September through November suggests a higher probability of warmer than normal temperatures for the Great Lakes Region, including eastern portions of Minnesota. The outlook also favors above normal precipitation for the Great Lakes area, including southern Minnesota. Further the CPC sees no development of an El Nino episode in the equatorial Pacific Ocean during the coming fall and winter season.

Climate Change Adaptation Conference at the Science Museum on November 7, 2013

Several organizations are partnering to host the first statewide conference on Climate Change Adaptation, Planning and Practice. It will take place at the Science Museum of Minnesota in downtown St Paul on November 7, 2013. Registration for the all day program is only $50. Sessions will be devoted to city planning, agriculture, transportation, natural resources (including watershed management), and public health.

Remembering Bill Larson

Bill Larson passed away last month, just a few weeks shy of his 92nd birthday. He was my boss from 1982 to 1989 when he served as Head of the Department of Soil, Water, and Climate at the University of Minnesota. I remember him as both an outstanding soil scientist and university administrator. Early in his career he was a promoter of soil conservation and evaluating soil health. His scientific achievements were widely recognized, as he won the Siehl Prize for Agricultural Research, was awarded an honorary doctorate by the University of Nebraska, and he was inducted into the USDA-ARS Science Hall of Fame. Bill advised many outstanding graduate students and expanded the department's expertise into the areas of water and climate with new faculty hires. I think he was one of the most respected scientists I have known, as well as an effective administrator. I consider myself lucky to have known him.

Meet us at the State Fair

MPR presents will be hosting a weather show on August 27th at noon, from the 2013 Minnesota State Fair Public Radio Booth at the corner of Judson and Nelson on the State Fairgrounds. Cathy Wurzer will serve as host with Paul Huttner and I in the booth to answer weather questions and put the past year's weather in perspective. Please consider this an invitation to drop by if you are at the Fair. Otherwise the hour-long broadcast will be carried by Minnesota Public Radio News and Information stations.

Weekly Weather potpourri

Earlier this month four former EPA Heads under Republican administrations voiced their concern for doing something about climate change in a New York Times opinion piece. It is worth a read and can be found at the NYTimes web site under archives.

After bringing heavy rains to the Philippines Typhoon Utor hit southern China and parts of Hong Kong on Wednesday this week with winds of 90 mph and heavy rains. Tens of thousands of residents were evacuated, schools and businesses were closed as well, along with ferry services. Some areas received over 4 inches of rainfall on Wednesday, and yet more rainfall is expected into the weekend adding to the flooding risk for many areas. Elsewhere the National Hurricane Center was issuing advisories on Tropical Storm Erin in the Eastern Atlantic Ocean near Cape Verde. It is expected to remain a tropical storm as it slowly crosses the Atlantic Ocean this weekend.

A study from Potsdam Institute for Climate Impact Research was published this week in the journal Environmental Research Letters and finds that Heat Waves will increase globally in frequency and amplitude regardless of emission scenarios. With mitigation efforts to curb global greenhouse gas emissions the study finds that the frequency chance in Heat Waves could stabilize by 2040. You can read more about this study here.

The Australian Bureau of Meteorology announced earlier this month the formation of a new National Centre for Extreme Weather. This new center will be staffed by 8 special meteorologists who will collaborate with other offices to deploy and coordinate new next generation flood forecasting models and Tropical Storm surge prediction schemes. The new Centre will also work closely with emergency managers and the media to see that urgent messages are immediately and widely distributed when necessary. You can read more about this here.

MPR listener question

Why do clouds tend to have flat bottoms and round tops?

Answer: There are of course a wide range of cloud types, but most have flat bottoms. The bottom of the cloud represents a layer that meteorologists call the Lifted Condensation Level (LCL), the height in the atmosphere where a rising plume of air will cool enough to reach saturation (100 percent humidity) and droplets will form. The LCL is related to the difference between air temperature and dewpoint (temperature at which condensation will occur) at the surface. Where the difference is large, the LCL tends to be at a higher elevation. Given that air temperature and dewpoint are typically similar over geographic areas that are several miles across, the rising air from the surface reaches a geographically uniform LCL, condensation occurs and the bottom layer of the cloud appears to be relatively flat with little variation in height. Conversely within the cloud plumes of microscopic water droplets may continue to rise or disperse due to strong updrafts and wind shear. This type of movement within the cloud will tend to give the perimeter edges and the top of the cloud a more rounded or lumpy appearance. These are the usual atmospheric motions that create clouds. Under some circumstances, especially with temperature inversions (increasing temperature with altitude) fog will form at the surface, and the top of the fog layer will be uniform, representing a warm enough layer of air that the atmosphere is no longer saturated, so from above it looks like the Earth is covered by a white blanket.

You can find almost every type of cloud depicted at the Cloud Appreciation Society web site, one of my favorites.


Twin Cities Almanac for August 16th


The average MSP high temperature for this date is 82 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 16th


MSP weather records for this date include: highest daily maximum temperature of 99 degrees F in 1988; lowest daily maximum temperature of 64 degrees F in 1943; lowest daily minimum temperature is 47 degrees F in 1962; highest daily minimum temperature of 77 F in 1988; and record precipitation of 1.97 inches in 2002; No snow has been recorded on this date.

Average dew point for August 16th is 59 degrees F, with a maximum of 76 degrees F in 1908 and a minimum of 40 degrees F in 1924.

All-time state records for August 16th

The state record high temperature for this date is 107 degrees F at Madison (Lac Qui Parle County) in 1988. The state record low temperature for this date is 27 degrees F at Tower (St Louis County) in 1976. State record precipitation for this date is 4.21 inches at Willmar (Kandiyohi County) in 1926; and no snow has fallen on this date. 

Past Weather Features:

August 16 was the middle of a Heat Wave in both 1922 and 1988. In 1922 an August Heat Wave visited the state from the 14th to the 18th and was very detrimental to crops. Over 35 Minnesota communities reported highs in the 90s F and six stations reached the century mark on their thermometers. In 1988 a Heat Wave prevailed from August 15 to 17 as over 40 Minnesota communities saw afternoon temperatures reach 100 degrees F or higher. The heat dissipated little at night as several observers reported overnight lows in the 80s F. Finally a cold front brought relief on the 19th, dropping the temperatures by 30 degrees F or more.

About 6:00 pm on August 16, 1926 an F-2 tornado (winds 113-157 mph) touched down in Becker County near Detroit Lakes. It destroyed a church and move along for 12 more miles, damaging some farms and homes along the way before lifting off to the east of the lake.

August 15-16, 1972 brought a flash flood to some north shore communities. Frequent lightning strikes accompanied the thunderstorms that dropped 1.5 to 4.5 inches of rainfall along a stretch of Highway 61 from Duluth to Castle Danger. There was widespread flooding of some basements and roads.

The coldest August 16th in state history occurred in 1976 when over 80 Minnesota communities reported morning low temperatures in the 30s F. Several northern observers reported minimum values in the 20s F. As far south as Grand Meadow (Mower County) frost was reported with a reading of just 30 degrees F.

About 6:00 pm on August 16, 2006 an EF-0 tornado (winds 40-72 mph) moved three miles across the Minnesota landscape in Roseau County near the town of Ross. It did little damage, but it was the 3rd tornado reported in Roseau County that summer, very unusual for that far north. Statewide there were only 25 tornado reports in 2006.

Friday, August 9, 2013

Significant rains

Significant rains

August 5-6 brought wind, hail, and heavy rains to some parts of the state, for many the first significant rainfall of the month. At least 20 counties reported large hail (nickel size to tennis ball size) for brief periods of time, while another four counties reported strong winds which damaged trees. Fast moving thunderstorms brought record setting rainfall amounts in some places. Among those setting new daily rainfall records were: Wells (1.95"), Winnebago (1.62"), Milan (1.42"), Vesta (1.34"), Montevideo (1.15"), and Litchfield (1.02"). Many other observers reported from 1 to 2 inches of rainfall, but did not set daily records. Albert Lea, Blue Earth, and Hutchinson observers reported over 2 inches. You can read a brief report on these storms at the State Climatology Office web site.

Cooler than normal temperature pattern

The cooler than normal temperature pattern from the last week of July has carried over into the first 9 days of August. Some observers have reported near record cold daytime highs in the 60s F. Overnight lows on August 4-5 in northern Minnesota dropped to the mid to upper 30s F, near record low values. International Falls tied the record coldest minimum temperature on Wednesday, August 7th with a reading of 40 degrees F (tied 1926), then on the morning of Thursday, August 8th several new record low temperature readings were set, including 37 degrees F at International Falls, 34 degrees F at Silver Bay and Wadena, and 39 degrees F at Crane Lake. In some southern Minnesota communities it is the coolest start to August since 2004. According to NOAA's Climate Prediction Center the cooler than normal temperature trend across the Great Lakes Region is expected to dominate through the first three weeks of August, then warmer than normal temperatures may dominate the rest of the month.

Meet us at the State Fair

MPR presents will be hosting a weather show on August 27th at noon, from the 2013 Minnesota State Fair Public Radio Booth at the corner of Judson and Nelson on the State Fairgrounds. Cathy Wurzer will serve as host with Paul Huttner and I in the booth to answer weather questions and put the past year's weather in perspective. Please consider this an invitation to drop by if you are at the Fair. Otherwise the hour-long broadcast will be carried by Minnesota Public Radio News and Information stations.

Weekly Weather potpourri

NOAA announced this week their 23rd Annual State of the Climate Report (for 2012), based on measurements, monitoring, and analysis of global scale climate data sets (not model projections). It includes a summary of temperature and precipitation trends and patterns, as well as descriptions of notable climate events. You can read a brief synopsis or the full report online.

The NOAA National Hurricane Center was monitoring Hurricane Henriette in the Eastern Pacific Ocean. It was spinning over a thousand miles east of Pearl Harbor, Hawaii with winds up to 110 mph. The track of Hurricane Henriette is expected to be well south of the Hawaiian Islands and it is expected to weaken considerably over the weekend. It was producing sea wave heights over 30 feet and expected to perhaps bring some rainfall to the islands.

The United Kingdom Meteorological Office launched a new web site this month called "My Climate & Me." It enables British citizens to put questions about weather and climate to leading experts using an online video magazine and roving reporter. The Met Office hopes that it will serve to educate citizens about climate and its effects on our quality of life and allow for better understanding of climate change and its implications. You can view the web site here.

NASA's Visible Earth provides a visualization of the planet "breathing" through seasonal animations of ice/snow cover, as well as vegetative greenness. It makes for an interesting view. You can see it at this web site.

Brad Rippey, USDA meteorologist assigned to the World Agricultural Outlook Board provided the following highlights in the drought briefing this week:

- Recent heavy rain has taken a bite out of exceptional drought (D4) across the central Plains and the Southwest, reducing the nation’s D4 coverage to 2.77%. That is down nearly one-half percentage point (0.40%) from a week ago, and represents the nation’s smallest D4 area since April 23. In the last week, D4 coverage fell from 25 to 21% in New Mexico; from 15 to 8% in Colorado; and from 4 to 1% in Nebraska.
- Overall U.S. drought coverage decreased slightly in the last week. Drought coverage is nearly twenty percentage points (19.96 points) below the peak coverage of 65.45% in late-September 2012.
- Drought returned to western Iowa, with 16.51% of the state covered by moderate drought (D1) on August 6. Similarly, D1 has recently returned to northern Missouri, with drought currently covering 15.42% of the state.
- The portion of the U.S. corn production area in drought has been edging upward in recent weeks, from 17 to 22% between July 9 and August 6. The increase has been largely due to resurgent drought in the western Corn Belt, including northern Missouri, eastern Nebraska, and western Iowa. Soybeans in drought have also increased in the last four weeks, from 8 to 14%.

Some parts of MO, AR, and TN received 6-8 inches of rainfall over Wednesday and Thursday this week, creating some flash flooding and washed out farm fields in some areas. The National Weather Service in Nashville, TN posted a summary of the rainfall, along with some photos of the flash flooding there. You can find those here.

The American Geophysical Union published a revised Statement on Climate Change recently and posted it on their web site. It is based on a synthesis of research and data analysis from recent years and clearly advocates for a set of policy priorities that include both climate adaptation and mitigation planning and activity. You can read it here.

MPR listener question

From a farmer attending Farm Fest in Morgan, MN this week...."I have some corn fields that are just tasseling now. Do you think the temperatures will warm enough so that my crop matures before the first autumn frost?"

Answer: Yes, beginning towards the end of this month temperatures are expected to warm and remain above normal as we enter the month of September. This will help to boost crop maturation. I think there is a good chance that most of the state's corn crop will reach maturation (black layer) before the first widespread frost.

Twin Cities Almanac for August 9th

The average MSP high temperature for this date is 81 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 August 9th

MSP weather records for this date include: highest daily maximum temperature of 95 degrees F in 1947 and 2010; lowest daily maximum temperature of 60 degrees F in 1994; lowest daily minimum temperature is 46 degrees F in 1888 and 1972; highest daily minimum temperature of 76 F in 2010; and record precipitation of 3.34 inches in 1914; No snow has been recorded on this date.

Average dew point for August 9th is 59 degrees F, with a maximum of 79 degrees F in 1992 and a minimum of 37 degrees F in 1927.

All-time state records for August 9th

The state record high temperature for this date is 104 degrees F at Canby (Yellow Medicine County) in 1947. The state record low temperature for this date is 28 degrees F at Tower (St Louis County) in 1994. State record precipitation for this date is 5.25 inches at Two Harbors (Lake County) in 1939; and no snow has fallen on this date.

Past Weather Features:

Persistent rains and occasional thunderstorms brought some flooding to many northern Minnesota communities over August 7-9, 1939. Many areas received over 3 inches of rainfall, while Virginia received over 4 inches and Two Harbors reported nearly 5 inches. In fact August of 1939 was the wettest in history for Two Harbors, totaling 10.86 inches for the month.

1947 brought the hottest August 9th in state history with over 40 communities reporting daytime highs in the 90s F. Seven western Minnesota cities hit 100 degrees F or higher. The cool spot that day was Grand Marais which reported a high of only 61 degrees F. For western counties the August Heat Wave of 1947 was one of the longest in history, lasting from the 1st to the 13th of the month.

Perhaps the coldest August 9th occurred in 1972. A cool Canadian high pressure system brought overnight lows in the 30s F to over 20 Minnesota communities. It was just 39 degrees F as far south as Pipestone and Zumbrota. In the north observers at Bigfork, Karlstad, Wannaska, Tower, and Thorhult reported frost. Temperatures warmed into the 80s F two days later.

An F-0 tornado (winds 40-72 mph) touched down at 1:35 am on August 9, 1993 in Littlefork, MN. It was only a brief touchdown (about 1 mile in length) but it turned over a mobile home, killing both people inside. Earlier that evening another tornado had touched down near Roseau, MN damaging a warehouse there.

Outlook

Mixed weather over the weekend with cooler than normal temperatures. Generally sunny and pleasant on Saturday, then increasing clouds with chances for showers overnight and into Sunday. Dry on Monday and Tuesday with near normal temperatures and another chance for showers by Thursday of next week in southern counties.
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