HydroClim Minnesota for early March 2019

HydroClim Minnesota for Early March 2019

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: March 7, 2019

What happened in February 2019:

• February monthly precipitation totals were well above historical averages at nearly all of Minnesota's reporting stations. The wettest locations were in east central, southeast and south central parts of the state, where precipitation totals were three inches or more. In some southeastern locations, precipitation totals for February 2019 were 300% of normal.
  [see: February 2019 Precipitation Total Map  | February 2019 Precipitation Departure Map  | February 2019 Climate Summary Table  |  February 2019 Percent of Normal Precipitation Map]
• There were a number of snow events during the very active weather pattern of February 2019.


• Heavy snow fell in northwestern Minnesota from Sunday to Monday, February 3-4, along with icy conditions over southern and eastern parts of the state.[see: Snow and Ice, February 3-4, 2019]
• Heavy snow spread over much of southern Minnesota on Tuesday February 5, creating major traffic problems for the second day in a row.[see: Heavy Snow in Southern Minnesota, February 5, 2019]
• An extremely active mid-winter pattern dealt another blow to Minnesota with a blizzard on February 6-7, with heavy snow, gusty winds, whiteout conditions in open country, falling temperatures, and dangerous wind chills.[see: Blizzard, February 6-7, 2019]
• Snow blanketed southern Minnesota once again on Sunday February 10, 2019.[see: More Snow, February 10, 2019]
• Moderate to heavy snow associated with a strengthening storm system to our east affected Minnesota yet again on Monday evening and Tuesday, February 11-12, 2019.[see: More Snow, Again! February 11-12, 2019]
• After a brief respite, the snowy February resumed, as the sixth heavy snow of February 2019 broke a slew of weather records across the state on February 20.[see: Another Heavy Snowfall, February 20, 2019]
• During an already historically-snowy month, a winter storm began on February 22nd, 2019, and turned into a massive and crippling blizzard in southern Minnesota by February 23rd and 24th. The storm produced 10-14 inches of snow and 50 mph wind gusts, shutting down multiple hundreds of miles of Interstate, US, and state highways, stranding hundreds of motorists, and whipping up snow drifts the size of houses.[see: Winter "Bomb" Cyclone, February 22-24, 2019]


• Statewide temperatures in February were well below normal, with a preliminary average of 5.4 degrees or 9.9 degrees below normal. February 2019 ranked as the 17th coldest out of 125 years. February 2018 was also below normal with 8.4 degrees for the average temperature.
  [see: Minnesota Climate Trends  |  February 2019 Climate Summary Table  |  2019 February Departure from Normal Temperature Map]

Where we stand now:

• From late February to early March, a very deep snowpack covered the state with many locations ranging from 18 to 24 inches. Snow depths of 30 to 40 inches can be found in the Lake Superior Highlands. Much of the state has a snow depth ranking in the 95% to nearly the deepest snow depth for the date (March 7).
  [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 March 7 shows that Minnesota is free of drought. The last time Minnesota was drought-free was in May 2017. 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 flow measurements (where winter measurements are possible) are near normal to much above normal when compared to historical medians for the date.
  [see: USGS Stream Flow Conditions]
• In their final report of the 2018 growing season (November 25), the Agricultural Statistics Service reported that topsoil moisture across Minnesota was 0 percent Very Short, 1 percent Short, 75 percent Adequate, and 25 percent Surplus. History has shown that soil moisture conditions observed in the late autumn are indicative of conditions to be expected when the soil thaws. Soil moisture readings at Waseca and at Lamberton finished above the historical median for the final report for 2018 back on November 1.
  [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]
• Many locations have frost depths of two to four feet. Typically the maximum frost depth occurs near the end of February. Thawing has not begun yet.
  [see: National Weather Service Frost Depth Data  |  MnDOT Road Frost Depths  |  University of Minnesota - St. Paul Campus Soil Temperatures Under Sod]
• Minnesota lakes, rivers, and wetland complexes continue to be ice covered. In general lakes first froze over in the middle of November. Some lakes had one of their earlier lake freeze over dates in recent years. Lake and river ice is never completely safe. On March 6, Lake Superior was 93.5% covered by ice, a much higher percentage for this date than the last two years. The last time there was this much ice on Lake Superior was in late February 2015, with 95.7% ice coverage. The 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 March precipitation outlook has equal chances for below normal and above normal precipitation. Historically, average March precipitation totals range from near three-quarters of an inch in northwestern Minnesota to around two inches in southern sections of the state. March is a transition month when cold, dry continental air masses are gradually replaced by warmer, moister air on a more frequent basis. This is demonstrated by the fact that March's normal precipitation is 50 percent higher than February's normal precipitation, the greatest percentage increase between any two successive months.
  [see: Climate Prediction Center 30-day Outlook  | March Precipitation Normal Map]
• The March temperature outlook has a strong tendency for below normal temperatures, especially in western Minnesota. Normal March high temperatures climb from near 30 degrees early in the month to the low to mid-40s by month's end. Normal March lows begin the month in the single digits above zero in the far north and mid-teens in the south. By late March, normal lows are in the low 20s in the north, near 30 in the south.
  [see: Climate Prediction Center 30-day Outlook  | March Temperature Normal Map]
• The 90-day precipitation outlook for March through May indicates equal chances for below, normal and above normal precipitation. The March through May temperature projection also indicates equal chances for below, normal and 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 normal to much above normal relative to historical flows for the date
  • soil profiles are moist due to above normal precipitation in 2018, especially in southern Minnesota.
  • frost depths range from two to four feet and have not begun to thaw.
  • snow depths are much above the historical median for the date in Minnesota, with snow water equivalent also well above normal.
  [see: National Weather Service - North Central River Forecast Center]

From the author:

• Many places in Minnesota set records for the snowiest February on record, including the Twin Cities with 39 inches, which also made February 2019 the 4th snowiest month on record.

Upcoming dates of note:

• March 21: National Weather Service releases 30/90 day temperature and precipitation outlooks

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Pete Boulay, DNR Climatologist