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: February 12, 2021
What happened in January 2021:
- January 2021 was a month of normal to below normal precipitation in the northern and central portions of the state, with normal to above normal precipitation in the south. One of the wetter locations was Jordan in Scott County with 1.03 inches, .30 inches above normal. One of the drier locations was Grand Portage with .30 inches or 1.13 inches below normal. The preliminary statewide precipitation average for January 2021 was .68 inches or 0.11 inches below normal. In comparison, statewide precipitation for January 2020 was a little above normal.
[see: January 2021 Precipitation Map | January 2021 Precipitation Departure Map | January 2021 Climate Summary Table | January 2021 Percent of Normal Precipitation Map ] - The main precipitation event of January 2021 was a sloppy winter storm of January 14-15. An unusually warm winter storm produced an expansive mass of rain and wet snow, mucking up roads and leaving behind treacherous ruts and mats of crusted slush across much of Minnesota. Snowfall totals reported in Minnesota included 8.3 inches near Ellendale, measured by a CoCoRaHS observer; 7.5 inches near the Worthington airport; 6.5 inches measured by the Cooperative National Weather Service observer in Owatonna; and 4.6 inches in Rochester. The Twin Cities recorded 2.9 inches officially, with the long-term stations at Duluth, St. Cloud, and International Falls all reporting around an inch-and-a-half.
[see: Sloppy Winter Storm, January 14-15, 2021] - Temperatures for January 2021 were a continuation of the balmy December 2020. There were multiple days that were above freezing in the state, including northern locals like International Falls, which saw a high temperature of 40 degrees on January 3. The Twin Cities did not see a minimum of zero or colder in January 2021, a feat only accomplished in two other years, 1990 and 2006. The preliminary statewide average temperature for January 2021 was 19.0 degrees or 7.5 degrees above normal. The warmest temperature of January 2021 was 52 degrees at Lamberton, Marshall and Windom on the 14th and the coldest temperature of the month was -37 degrees at Norris Camp on the 27th.
[see: January 2021 Climate Summary Table | January 2021 Departure from Normal Temperature Map
Where we stand now:
- As of February 11, snow depth readings are a little bit deeper than the historical median across most of southern Minnesota, near the median across central Minnesota and below the median in the north. The snow is especially scarce in the far western part of the state, where there is little to any snow cover in Traverse and Big Stone Counties. The deepest snow is in its typical location, in the highlands of Lake Superior where snow depths are approaching two feet in some locations. However, even along the North Shore, snow depth is falling a bit below the median.
[see: Weekly Snow Depth and Ranking Maps | NWS Snow Depth Estimation Map | Midwest Regional Climate Center Snow Depth Map ] - The U. S. Drought Monitor map released on February 11, 2021 depicts the entire state with some level of drought designation. Last year at this time the state was free of any drought. About 75% of the state was Abnormally Dry, and 24% of the state in Moderate Drought conditions. A small area in Rock County in southwest Minnesota had Severe Drought conditions. 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 values (where winter measurements are possible) range from below the historical median for the date in the northeast, to normal and above the historical median for the date in the central and south. Few Minnesota rivers have stream flow data. Most rivers and streams are now impacted by ice.
[see: USGS Stream Flow Conditions] - In their final report of the 2020 growing season (November 30), the Agricultural Statistics Service reported that topsoil moisture across Minnesota was 2 percent Very Short, 11 percent Short, 83 percent Adequate, and 4 percent Surplus.
[see: Agricultural Statistics Service Crop Progress and Condition | U. of M. Southwest Research & Outreach Center (Lamberton) | U. of M. Southern Research & Outreach Center (Waseca)] - The potential for wildfires is currently rated by DNR Forestry as Low across Minnesota.
[see: Fire Danger Rating Map] - Soil frost depths under sod are very shallow for early February, depending on snow cover. Frost depths are generally a foot or less in the central and south and one to two feet in northwest Minnesota. Soil temperatures at the U of M St. Paul Campus Climate Observatory have stayed near 32 degrees at the four inch depth throughout much of the winter.
[see: National Weather Service Frost Depth Data | MnDOT Road Frost Depths | University of Minnesota - St. Paul Campus Soil Temperatures Under Sod] - Lake ice in started early due to the cold conditions in mid-November, but mild conditions that followed caused some lakes to thaw and to refreeze again. Some lakes stayed frozen, others had multiple freeze-thaw dates. In general lakes first froze over for good during the last week of November to first half of December, a few days later than historical averages. Mille Lacs froze over around December 3, one day later than its median date. Lake and river ice is never completely safe. On February 12, Lake Superior had nearly 14% ice cover, and increase of about ten percent over the past week. Maximum ice coverage for Lake Superior typically happens in late February.
[see: DNR Conservation Officer Reports | Median Lake Ice-In Dates | Great Lakes Ice Cover]
Future prospects:
- The February precipitation outlook has a tendency for above normal precipitation, for not only Minnesota, but the entire upper Midwest. February is typically the driest month of the year. Precipitation normals range from near one-half inch of liquid equivalent in western Minnesota to just over three-quarter of an inch of precipitation in eastern sections of the state. The median snow depth at the end of February ranges from under five inches in southwest Minnesota to over 18 inches on the ground in northeastern Minnesota (greater than 30 inches in the Lake Superior highlands).
[see: Climate Prediction Center 30-day Outlook | February Precipitation Normal Map] - The February temperature outlook has a strong tendency for below normal temperatures. As of February 11, the preliminary average temperature for February in Minnesota is 10 degrees below normal, so indeed the month will likely finish well below normal. There are signs for some above normal temperatures for the last week of the month. Normal February high temperatures range from the low teens in the north to near 20 in the south early in the month, climbing to the mid-20s to low 30s by month's end. Normal February low temperatures range from near minus 10 degrees in the far north to the single digits above zero in southern Minnesota early in the month; ascending to the low single digits in the north, mid-teens in the south by the end of February.
[see: Climate Prediction Center 30-day Outlook | February Temperature Normal Map] - The 90-day precipitation outlook for February through April indicates a tendency for above normal precipitation in northern and central Minnesota with equal chances for above and below normal precipitation in the south. . The February through April temperature projection indicates a tilt towards above normal temperatures.
[see: Climate Prediction Center 90-day Outlook] - The National Weather Service produces long-range probabilistic river stage and discharge outlooks for the Red River, Minnesota River, and Mississippi River basins. These products address both high flow and low flow probabilities. Here are the current weather conditions impacting prospects for spring snow melt flooding:
- present stream flows are near average to somewhat above average to historical flows for the date
- soil moisture profiles are near the historical medians in the south.
- frost depths are relatively shallow.
- snow depths are slightly above the historical median in the south, near historical medians over central, and below historical medians in the north.
From the author:
- So far February has been very cold in the state. While the cold does not have the intensity of some of the past cold spells, this one happens to be long-lived. At International Falls through February 12, the mercury has stayed at or below zero for seven straight days. The record below zero streak for International Falls is 14 days in January, 1912. If this current streak reaches ten days, it would be the longest since a ten day stretch in 1971.
Upcoming dates of note:
- February 18: National Weather Service releases 30/90 day temperature and precipitation outlooks
- Late-February: National Weather Service releases updated spring flood probabilistic outlooks
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