A monthly electronic newsletter summarizing Minnesota's climate conditions and the resulting impact on water resources. Distributed on the first Thursday of the month.
State Climatology Office - DNR Division of Ecological and Water Resources, St. Paul
distributed: June 5, 2020
What happened in May 2020:
- Precipitation for May 2020 in Minnesota ranged from well above normal in the southeast, near normal in the Twin Cities and below normal for most of central and northern Minnesota. The wettest location was 6.96 inches at Altura in southeast Minnesota, 3.09 inches above normal. The driest place was Melrose in central Minnesota with .67 inches or 2.59 inches below normal. Only .83 inches of rain fell at Morris, the eighth driest May there since records began in 1885. St. Cloud had the 9th driest May on record with 1.05 inches or 2.31 inches below normal. Overall the state was 3.06 inches or .27 inches below normal.
[see: May 2020 Precipitation Total Map | May 2020 Precipitation Departure Map | May 2020 Climate Summary Table | May 2020 Percent of Normal Precipitation Map]
- The first part of May was cold with some nuisance snow falling on May 9, the fishing opener. The most significant weather event of the month was the soaking rains of May 16-17. A potent low pressure system crossed the region slowly, producing widespread soaking rains along and to the north of its track, beginning on Saturday May 16, and lasting through Sunday May 17 in many parts of southern and eastern Minnesota. The Twin Cities saw 2.93 inches for the two day period. [see: Soaking Rain, May 16-17, 2020]
- The first tornadoes to touch down in the state happened on May 26. The National Weather Service confirmed that two of the storms produced small tornadoes. One was reported in residential Rosemount in Dakota County, where a small area of light damage occurred. Another tornado traveled for a half-mile in Freeborn County, producing scattered tree damage.[see: Storms, May 26, 2020]
- The preliminary statewide average temperature was 1.5 degrees below the 1991-2010 normal. The first half of the month was much colder than the second half. May 1-15 was 5.8 degrees below normal, with some well below freezing temperatures statewide on the 9th. Rochester had a low temperature of 27 degrees on the 9th. May 16-31 was 2.3 degrees above normal statewide. The warmest temperature found in the state for May was 89 degrees at Granite Falls on May 1st and at Sebeka on May 28. The coldest temperature found was 14 degrees at Brimson.
[see: Minnesota Climate Trends Tool | May 2020 Climate Summary Table | 2020 May Departure from Normal Temperature Map]
Where we stand now:
- Seasonal precipitation so far (April 1 through June 2) shows that the majority of the state has below to much below average precipitation. The only exception is the southeast where there are pockets of above normal precipitation in the southeast.
[see: Weekly Precipitation Maps]
- The U. S. Drought Monitor map released on June 4, shows Abnormally Dry conditions over 56% of the state. The driest locations are in west central and north central Minnesota with areas of Moderate drought. The last time there were widespread areas in the Moderate drought category was May 2015, and the last time there was substantial coverage (80% or greater) of the Severe drought category was in 2013. The U.S. Drought Monitor index is a blend of science and subjectivity where drought categories (Moderate, Severe etc.) are based on several indicators.
[see: Drought Conditions Overview]
- In general, stream flows in the central and north were normal to below normal. There were a few pockets, especially in the north central part of the state with low flow conditions. In the southeast there are normal to above normal streamflow conditions with some much above normal stream flows in the far southeast.
[see: USGS Stream Flow Conditions]
- Water levels on most Minnesota lakes vary depending on lake and location in the state. Mille Lacs lake level for early June was about a half-foot higher than the median. The level of Mille Lacs has been falling over the past month, during the time it has historically been on the rise. The level on Lake Minnetonka on June 5 was at 929.39 feet with 150 cfs flowing through Gray's Bay Dam. White Bear Lake was 925.22 feet on June 5, about a tenth of a foot lower than this time last year. Water has been flowing out of White Bear Lake at the outlet continuously since late April 2019. Lake of the Woods fell below the median band by the end of May. Rainy Lake is on the lower end of the median band. Lake Superior was forecast to be 602.62 feet for June 5, six inches lower than a year ago and two inches above the monthly average for early June.
[see: Mille Lacs Lake Water Level | Lake Minnetonka Water Level | White Bear Lake Water Level | Lake of the Woods Control Board Basin Data | Corps of Engineers Great Lakes Water Levels]
- The Agricultural Statistics Service on June 1 reported that topsoil moisture across Minnesota is 2 percent Very Short, 10 percent Short, 79 percent Adequate, and 9 percent Surplus. Soil moisture readings at Lamberton on June 1 shows the moisture profile below historical averages.
[see: Agricultural Statistics Service Crop Progress and Condition | U. of M. Southwest Research & Outreach Center (Lamberton)]
- The potential for wildfires is currently rated by DNR Forestry as Low across central and southern Minnesota, with Moderate and High fire danger rating in the north. There are also some pockets of Very High fire danger in west central and parts of northeast Minnesota. Historically, 80 percent of all wildfires in Minnesota occur during April and May.
[see: Fire Danger Rating Map]
- It took two months for lake ice out to progress across Minnesota in 2020. Lake Ice out began about a week ahead of the median in the central and south and wound up about a week or so late in the north. The first lake to lose its ice in 2020 was Lake Zumbro on March 14. The last lake ice out was Greenwood Lake in Cook County on May 17. The fishing opener was on May 9 and nearly all lakes were free of ice in the state except a handful in northern Cook County.
[see: Lake Ice Out: 2020]
- The precipitation outlook for June 2020 has equal chances for above normal and below normal precipitation across Minnesota. June precipitation normals range from just over three inches in northwest Minnesota to about five inches in southeastern counties.
[see: Climate Prediction Center 30-day Outlook | June Precipitation Normal Map]
- There is a tendency for above normal temperatures across the entire state in June, with the highest chance in southern parts of the state. Normal June high temperatures are in the low to mid 70s early in the month, rising to around 80 by month's end. Normal June low temperatures are in the low 50s to start the month, and rise to around 60 as the month ends.
[see: Climate Prediction Center 30-day Outlook | June Temperature Normal Map]
- The 90-day precipitation outlook for June through August indicates a slight tilt toward above normal precipitation totals over the state, with the best chance in the south. The June through August temperature projection shows equal chances for below, above and normal temperatures.
[see: Climate Prediction Center 90-day Outlook]
From the author:
Upcoming dates of note:
- June 18: National Weather Service releases 30/90-day temperature and precipitation outlooks