HydroClim Minnesota for Early June 2021
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 4, 2021
What happened in May 2021:
- Precipitation for May was generally below normal across the state, with some notable exceptions. The driest area was generally in a wide swath from west central to north central Minnesota, over the same areas that saw above normal precipitation in April. Some of the wettest areas in May 2021, were in the southeast which had below normal precipitation in April. The highest preliminary monthly total found so far was 6.75 inches at a location 1.8 miles southeast of Owatonna in Steele County. One of the lowest precipitation totals found was .24 inches or 3.19 inches below normal at Ottertail in west central Minnesota. The statewide preliminary total was 2.51 inches or 1.34 inches below normal.
[see: May 2021 Precipitation Total Map | May 2021 Precipitation Departure Map | May 2021 Climate Summary Table | May 2021 Percent of Normal Precipitation Map]
- There was one significant weather event in an otherwise quiet month for severe storms. Muggy air arrived in Minnesota on May 19, with a swarm of small evening tornadoes and the first intense rainfall of the year. Preliminary reports indicate that seven tornadoes touched down in southern Minnesota. All were small and caused little or no damage. While the outbreak of mini-tornadoes was plaguing southern Minnesota, parts of far northwestern Minnesota received the state's first intense rainfall event of the year. In this area, thunderstorms, some with very heavy rain, lined up along the leading edge of the moist air mass, with the storms "training" along that boundary for much of the night. By the morning of May 20, western Marshall County had received an estimated 2-5 inches of rain, with estimates of an inch or more reaching into adjacent portions of Polk, Kittson, and Roseau Counties. A DNR automated tipping bucket along the Tamarac River near Florian Park measured 24-hour rainfall totals of 4.18 inches as of 8 AM the 20th, and had reached 6.15 inches in 24 hours by 2 PM.
[see: Small Tornadoes and Heavy Rainfall, May 19-20, 2021]
- May began warm, had a series of cold and warm spells and ended up being close to normal. The preliminary statewide average temperature was .2 degrees above the 1991-2010 normal. The final frosty morning was on May 11 with a low temperature of 28 degrees at Waseca and 18 degrees at Embarrass. The warmest temperature of the month was 95 degrees at Granite Falls on May 1 and Sherburn on May 2nd.
[see: Minnesota Climate Trends Tool | May 2021 Climate Summary Table | 2021 May Departure from Normal Temperature Map]
Where we stand now:
- Seasonal precipitation so far (April 1 through June 1) shows that central and southern Minnesota has generally normal to below normal precipiation, with parts of northwest Minnesota having much below normal precipitation. An exception is a pocket of above normal precipitation in western Marshall County and a small area in west central Minnesota.
[see: Weekly Precipitation Maps]
- The U. S. Drought Monitor map released on June 3, shows Abnormally Dry conditions over 60% of the state. The driest locations are in southern and northwest MN with areas of Moderate drought. In far northwest Minnesota there is a sliver of Severe drought. 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]
- The U.S. Geological Survey reports that stream discharge stream flows in the central and north were below normal to much below normal. Stream flows were generally near normal in the south.
[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 May and early June has fallen below the median for the first time since 2018. The level on Lake Minnetonka on June 4 was at 929.29 feet with 20 cfs flowing through Gray's Bay Dam. White Bear Lake was 924.55 feet on June 4, about eight inches lower than this time last year. Lake of the Woods was at the lower end of the median band in early June. Rainy Lake is also on the lower end of the median band. Lake Superior was forecast to be 602.10 feet for June 4, six inches lower than a year ago and threee 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 4 percent Very Short, 20 percent Short, 71 percent Adequate, and 2 percent Surplus. Soil moisture readings at Lamberton on May 15 shows the moisture profile close to historical averages.
[see: Agricultural Statistics Service Crop Progress and Condition | U. of M. Southwest Research & Outreach Center (Lamberton)]
- Spring 2021 has been an active season for wildfires in Minnesota and fire danger is currently elevated. The potential for wildfires is currently rated by DNR Forestry as High across eastern Minnesota, including the Twin Cities, with Very High fire danger rating in the southwest and parts of the north central. There is a large area in central, northwest and north central Minnesota with Extreme fire danger. Historically, 80 percent of all wildfires in Minnesota occur during April and May.
[see: Fire Danger Rating Map]
- The precipitation outlook for June 2021 has a tendency for above normal precipitation in the north, with equal chances for above normal and below normal precipitation across the central and southern 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 fairly strong tendency for above normal temperatures across the entire state in June, with the highest chance in central and northern 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 equal chances for above, normal and below normal precipitation. The June through August temperature projection shows equal chances for below, above and normal temperatures, except across western Minnesota, where there is a tilt for higher temperatures.
[see: Climate Prediction Center 90-day Outlook]
From the author:
- The current heat wave is noteworthy for how early it is in the season. Looking at Early Season Heat Waves The run of 90 degree days in June 2021 in the Twin Cities might be memorable.
Upcoming dates of note:
- June 17: National Weather Service releases 30/90-day temperature and precipitation outlooks