Preliminary Climate Summary for May:
The most notable feature of the month was surplus rainfall. Most climate stations reported above normal rainfall amounts, and in some cases twice normal rainfall. The wettest part of the state was across the central counties where 4 to 6 inch amounts were common. Many places reported measurable rainfall on half the days of the month. Over 40 communities reported new daily record rainfall amounts for selected dates during the month. Some of these stations included: 2.40 inches at Minnesota on the 10th; 2.25 inches at Madison on the 11th; 2.00 inches at Montevideo on the 11th; 2.22 inches at Wheaton on the 11th; 2.75 inches at Collegeville on the 17th; 3.22 inches at Morris on the 17th; 3.65 inches at Lake Wilson on the 17th; and 2.10 inches at Hallock on the 18th. Overall some of the highest total rainfall values for the month exceeded 7 inches at places that included Morris, Montevideo, Cass Lake, and Ottertail, Some places in northern Minnesota reported small amounts of snowfall for the month including Tofte, Two Harbors, Orr, and Isabella
These so-called "rescue rains", a term used by many Minnesota farmers, helped transform the state drought situation significantly during May. When the month started over 94 percent of the state landscape was in moderate to severe drought, and as of the end of the month, less than 25 percent of the state is still in moderate drought, quite a remarkable turn-around. This was the 5th consecutive year that May has delivered above normal rainfall to the state, and May of 2015 will probably rank among the 15 wettest in state history.
In contrast to the month of April, wind speeds were generally less than normal during the month of May in most places around the state. There were a few severe thunderstorms with strong winds, and on May 16th tornadoes were reported in Lac Qui Parle, Chippewa, Pope, Swift, Meeker, Wright, and Stearns Counties. Fortunately no cities were hit by these storms, though there was some damage to barns near Darwin in Wright County and some tree and roof damage in Swift and Chippewa Counties. They were the first tornado reports in Minnesota for 2015.
Comparing Drought-Busting Rainfalls in MN, OK, and TX:
May 1-29 2015 rainfall in Minnesota (climate stations with roughly twice normal)
7.03" at Moorhead
7.02" at Cass Lake
7.19" at Park Rapids
7.01" at Montevideo
8.41" at Ottertail
7.31" at Morris
6.05" at Collegeville
6.50" at Brainerd
6.68" at Lake Wilson
May 1-29, 2015 rainfall in Oklahoma (climate stations with roughly 4 times normal)
May 1-29, 2015 rainfall in Texas (climate states with 3-4 times normal)
Houston (Sugarland) 18.03"
All of the reports from Oklahoma and Texas are either new record amounts for the month of May, or new record amounts for any single month of the year. Widespread, destructive flash flooding has occurred in both Texas and Oklahoma.
Weekly Weather Potpourri:
Jim Angel, State Climatologist for Illinois, wrote an interesting article this week for the Sustainable Corn Blog. It is about the potential impact of the current El Nino episode on the Corn Belt states. It is worth a read.
MPR Listener Question:
Twin Cities Almanac for May 29th:
MSP Local Records for May 29th:
MSP weather records for this date include: highest daily maximum temperature of 94 degrees F in 2006; lowest daily maximum temperature of 53 degrees F in 1947: lowest daily minimum temperature is 33 degrees F in 1965; highest daily minimum temperature of 74° F in 2006; record precipitation of 2.49 inches 1942; and no snowfall has been recorded on this date.
Average dew point for May 29th is 50 degrees F, with a maximum of 72 degrees F in 1953 and a minimum of 25 degrees F in 1947.
All-time state records for May 29th:
Past Weather Features:
Strong thunderstorms brought record-setting rainfall and flash flooding to many parts of the state over May 29-30, 1942. Red Wind and Zumbrota received over 4 inches of rain, but most of the real damaging rainfalls occurred around the Twin Cities area. Minneapolis downtown reported 7.07 inches, downtown St Paul received 5.89 inches, and Maple Plain reported 6.40 inches. Many roads were underwater for a day or two.
A strong thunderstorm on May 29, 1949 dropped 4.50 inches of rain on Mahnomen and 7.50 inches of rain on Thief River Falls in a period of just 6 hours. Many farm fields were flooded, but eventually recovered.
May 29, 1947 brought widespread damaging frosts to many parts of the state. Morning low temperatures in the 20s F and low 30s F were common throughout the state causing crop damage and damage to tender garden plants as well. Frosts occurred as far south as Austin and Grand Meadow, while Thief River Falls in northwestern Minnesota went down to just 21 degrees F. For a brief time on May 29th a freak snow storm occurred depositing a trace of snow in many places and some measurable amounts in a few spots including Spring Grove, Albert Lea, Harmony, Tower, Caribou, Baudette, Worthington, and Grand Meadow.
Thunderstorms and heavy rains over May 28-30, 1953 caused the Red River to reach flood stage in northwestern Minnesota. Many observers in the northwestern counties reported 2 to 5 inches of rainfall over that time period. Roads and culverts were washed out in parts of Wilkin, Clay, and Ottertail Counties, and a 500 foot section of railroad tracks washed out in northern Wilkin County, taking weeks to repair.
May 29, 1965 brought another widespread frost, damaging many corn fields around the state. In the north temperatures fell into the 20s F in many places and widespread frosts were noted even in the suburbs of the Twin Cities. In southeastern Minnesota Caledonia reported a low of 27 degrees F, while Zumbrota reported just 28 degrees F.