Some record-setting rains this weekWidespread rainfall was reported around the state this week, adding to an already wet month. Warm, moist air (dewpoints from 66 F to 70 F) produced strong thunderstorms which brought heavy rainfall to parts of northwestern and southeastern Minnesota overnight from May 29-30. In some cases new daily record amounts were set, including: 2.22 inches at Hokah, 2.59 inches at La Crescent, 2.32 inches at Spring Grove, 2.85 inches at Moorhead, 3.00 inches at Browns Valley, and 3.77 inches at Fargo, ND. As a result of these heavy rains the National Weather Service issued flash flood watches for some areas.
Preliminary climate summary for May 2013For the 4th consecutive month Minnesota observers reported monthly mean temperatures that were cooler than normal. Most reports ranged from 1 to 3 degrees F cooler than normal for May. Combined with the temperature data for March and April, the overall spring temperatures (March-May) were the third coldest in state history, trailing only 1907, and 1950. Extremes for the month ranged from 103 degrees F at Sherburn (Martin County) and Winnebago (Faribault County) on the 14th to just 15 degrees F at Camp Norris (Lake of the Woods County) on the 12th.
Most observers reported above normal precipitation for the month of May, ranging from 4 to 6 inches. In many southern counties monthly precipitation was well above normal, and in some areas record-setting. Those reporting a new record wet May included: Austin (10.98"), Grand Meadow (14.64"), La Crescent (10.91"), Rochester (11.03"), Spring Valley (12.23"), Dodge Center (9.03"), Lanesboro (9.91"), and Theilman (10.58"). Fargo, ND reported its 2nd wettest May in history with 7.06 inches. In addition, many observers reported precipitation on over 22 days during the month.
Combined with the precipitation for March and April, the overall spring season (March-May) was the wettest in history for southeastern Minnesota, saturating soils, and putting streams and rivers near bank full. Statewide this spring is likely to end up among the top ten wettest in history.
The snow storm over the first few days of May established some records in southeastern Minnesota as well. Dodge Center reported a statewide daily record snowfall for May with 15.4 inches on the 2nd. Observer reports for snow totals ranged from 9 inches (Albert Lea) to 17.3 inches (Ellendale) across many areas of southern Minnesota in one of the snowiest Mays in state history.
Winds of 50-60 mph associated with strong thunderstorms over May 19-20 caused some damage in southern Minnesota to trees.
Weekly Weather potpourri
From Omaha.com this week there was a statement from Iowa State Climatologist Harry Hillaker, "the average rainfall of 16.4 inches during the months of March, April, and May is the most (statewide) in 141 years of records." The previous statewide record value for the spring months was 15.5 inches in 1892, while normal is about 10 inches. Rains were pounding Iowa much of this week, preventing farmers from planting and bringing most rivers and streams to bank full, and some to moderate and major flood stage, including the Cedar and Iowa Rivers. Many Iowa observers report over a foot of rain this May.
USDA Meteorologist Brad Rippey's comments on drought this week:
-Overall U.S. drought coverage fell 1.73 percentage points to 44.34%, and has decreased during 27 of the last 35 weeks. Drought coverage is down 16.75 percentage points since the beginning of 2013 and down 21.11 points from the record high of 65.45% on September 25, 2012.
- The portion of the contiguous U.S. in the worst category – D4, or exceptional drought – decreased slightly (0.20%) to 4.74%. Compared to a week ago, there were slight increases in D4 coverage noted in Kansas (22%) and Oklahoma (11%). D4 coverage was unchanged or decreased slightly in New Mexico (45%), Texas (16%), Colorado (16%), and Nebraska (4%). More information can be found here.
News from overseas included a story about a tornado that struck near Milan, Italy this week causing some damages and surprising morning commuters. The same storm system produced some late season snows in the Alps. The United Kingdom Meteorological Office reported that country has recorded their coldest spring since 1962 and 5th coldest of all-time.
NOAA unveiled a new look to its "climate.gov" web site this week. It offers more features, a global climate dashboard to view data, and several additional links to other information. If you want to try it out, click here.
Environment Canada has reported two tornadoes in Ontario this May. The average annual number of tornadoes reported in Ontario is 12. Earlier this week they reported severe thunderstorms, but no tornadoes.
MPR listener questionWhat is the northern most weather reporting station in Minnesota and what is the southern most? How many miles apart are they?
Answer: At 49 degrees 32 minutes north latitude, Flag Island on the Northwest Angle in Lake of the Woods is the most northerly climate station in Minnesota. The most southerly stations are Harmony in Fillmore County and Spring Grove in Houston County. Both are located at 43 degrees and 34 minutes north latitude. The distance from Spring Grove to Flag Island is roughly 500 miles. Obviously, Flag Island is a much colder place on average than either Spring Grove or Harmony, with many more below 0 F readings in the winter.
Twin Cities Almanac for May 31stThe average MSP high temperature for this date is 74 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 54 degrees F (plus or minus 8 degrees F standard deviation).
MSP Local Records for May 31stMSP weather records for this date include: highest daily maximum temperature of 106 degrees F in 1934; lowest daily maximum temperature of 55 degrees F in 1962; lowest daily minimum temperature of 33 F in 1889; highest daily minimum temperature of 75 F in 1934; and record precipitation of 2.39 inches in 1965; No snow has been recorded on this date.
Average dew point for May 31st is 50 degrees F, with a maximum of 73 degrees F in 1961 and a minimum of 27 degrees F in 2009.
All-time state records for May 31stThe state record high temperature for this date is 112 degrees F at Maple Plain (Hennepin County) in 1934. The state record low temperature for this date is 19 degrees F at Pokegama Dam (Itasca County) in 1889. State record precipitation for this date is 4.92 inches at Maple Plain (Hennepin County) in 1888; and the state record snowfall for this date is 4.6 inches at Virginia (St Louis County) in 1946.
Past Weather Features:Widespread frost occurred around the state on May 31, 1889 causing some farmers to replant crops. Temperatures fell into the 20s and low 30s F in many northern and central counties.
Another damaging frost occurred on May 31, 1897 when temperatures fell into the upper 20s and low 30s F. Corn had to be replanted in many spots, though some was left to cut for silage. Morning low temperatures fell to 28 degrees F as far south as Pleasant Mound and Grand Meadow.
May 31, 1934 brought the highest temperature ever recorded in May (112 degrees F at Maple Plain). Afternoon relative humidity that day was just 13 percent, and relative humidity of less than 20 percent was recorded on 15 days that month. Most places received less than an inch of rain during the (some less than 0.20"). Some of the worst dust storms ever recorded in the state occurred, depositing up to 6 inches of soil across many Minnesota roads. Western and northern areas were also plagued with brush, forest and peat fires.
May 31, 1946 brought snow to many communities in northeastern Minnesota, including Babbitt, Tower, Two Harbors, and Virginia. A trace of snow was reported as far south as Willmar. The snow was short-lived as temperatures climbed into the 50s F on June 1st.
May 31, 1959 brought thunderstorms to parts of Minnesota. These storms produced heavy rains and strong winds. Lakefield reported an unofficial rainfall of 5.60 inches, but many other areas received 2-3 inches of rainfall which caused some flash flooding. Winds of 50 mph and higher blew down some trees and electrical poles causing power outages in Blue Earth and Hennepin Counties. This storm brought an end to one of the wettest June's in state history, as many southern Minnesota observers reported over 9 inches for the month (10.41 inches at Fairmont)
At 3:30 pm on the afternoon of May 31, 1971 an F-2 tornado (winds 113-157 mph) passed 4 miles southwest of Lakefield, MN (Jackson County). It destroyed a barn and left several dead cattle before dissipating after being on the ground for 2 miles.