March 10th Record Warmth

March 10th Record Warmth:

Monday, March 10 was one for the record books in Minnesota, as over 50 long term climate stations (mostly western counties) reported setting new high daily maximum temperatures. Duluth set a record of 62°F and St Cloud set a record of 69°F. MSP just missed tying the record high for the date (66°F) reaching 65°F in the late afternoon. Several readings of 70°F or greater were reported from western Minnesota, where snow cover was sparse or nonexistent. Redwood Falls set a new all-time statewide record high for the date with a reading of 75°F. Milan, Marshall, and Lamberton all reached 73°F. A few locations in western Minnesota also set new daily records for warm minimum temperatures. For example, the low at Canby (Yellow Medicine County) was a record warm 38°F.

In addition, there were unusually low afternoon relative humidity readings ranging from just 15 to 19 percent for a few hours, and winds were gusting to 30 mph or greater for a time. This was cause for the National Weather Service to issue many Red Flag warnings for several counties.

So far this month temperatures are averaging 8°F to 10°F above normal around the state, and near-record to record-setting high temperatures are forecast for Friday, March 14th before a cold front moves across the state Friday night and Saturday. Despite a cool weekend, I still expect mostly warmer than normal temperatures to prevail the remainder of the month.

Insect Mortality Assessment for This Winter:

Sometimes in winters with plentiful subzero temperature readings, overwintering or egg laying insect pests in Minnesota suffer from higher mortality rates, and their spring and summer populations can be set back a bit. Dr. Anthony Hanson of the University of Minnesota Extension posted a very interesting blog this week discussing the mortality inflicted on insect pests in Minnesota this winter by the many subzero nighttime temperatures recorded around the state. Many areas of the state saw temperatures fall to -25°F during the winter months, and some reached -30°F or colder. There were even a few readings of -40°F. Such temperatures can be lethal to various insect pests. Dr. Hanson estimates that for portions of north-central Minnesota soybean aphid (a monitored pest during the crop season) mortality may reach 25 percent or greater. For Emerald Ash Borer (one of the lethal pests for ash trees), he estimates 10 percent or less mortality in southern counties, but 25 percent mortality or more in northern areas of the state. If you want to read more of his assessments, I encourage you to read his blog on the Extension web site.

Weekly Weather Potpourri:

Many areas of the United Kingdom have been experiencing wild swings in temperature during March, similar to what has been happening in Minnesota. After temperatures reached near-record highs last Sunday (low to mid 60s F), this week brought a cold front the pushed temperatures well below freezing and brought daily highs only in the 30s and 40s F, according to the BBC Weather Center.

Time magazine had a feature story this week describing the proposed cuts to NOAA by the Trump administration. In terms of value for money, NOAA is second to none in providing public service using knowledge and information from a team of scientists and engineers, along with up-to-date technologies 24/7 to advise and alert industry and infrastructure operations, as well as provide the public with sound forecasts of the weather, including threats from severe weather. This article highlights how detrimental the proposed cuts would be in terms of public safety and stifling the improved public understanding of climate change and its consequences. I hope it provokes a public backlash against these cuts.

MPR listener question:

In recent years we have seen less snowfall in southern and central Minnesota, with frequent warmer than normal temperature. Is this going to be the new normal for these parts of the state? If so, people who like to ski, skate, snowshoe or ice fish will be sad.

Answer:

New climate normals will be calculated for all climate stations after the year 2030. They will represent average values for the period from 2001 to 2030. If we look at the trend in snow seasons for places like the Twin Cities and Saint Cloud since the winter of 2000-2001, there is little movement in the average total snowfall across the years (up through 2024). The moving 30 year average may vary by 5 to 8 inches. More importantly is the steep upward trend in winter temperatures. Some areas of the state have seen increasing of 6°F to 8°F in average winter season temperatures, and much more frequent freeze-thaw cycles, as well as prolonged thaw periods. These characteristics are definitely a new normal for us in southern and central Minnesota and are leading to a highly erratic snow cover season (lack of consistency) as well as a shrinking lake ice season.

Twin Cities Almanac for March 14th:

The average MSP high temperature for this date is 41 degrees F (plus or minus 12 degrees F standard deviation), while the average low is 24 degrees F (plus or minus 12 degrees F standard deviation).

MSP Local Records for March 14th:

MSP records for this date: highest daily maximum temperature of 73 degrees F in 2012; lowest daily maximum temperature of 8 degrees F in 1906; lowest daily minimum temperature of -10 degrees F in 1897; highest daily minimum temperature of 48 degrees F in 2016, and record precipitation of 0.81 inches in 1989. Record snowfall is 7.2 inches also in 1989.

Average dew point for March 14th is 21°F; the maximum dew point on this date is 57°F in 1990 and the minimum dew point on this date is -16 degrees F in 1960.

All-time state records for March 14th:

The state record high temperature for this date is 74 degrees F at Rochester (Olmsted County) in 2012. The state record low temperature for this date is -35 degrees F at Leech Lake (Cass County) in 1896 and at Beardsley (Big Stone County) in 1897. The state record precipitation for this date is 1.90 inches at Rochester (Olmsted County) in 1918. The statewide snowfall record for this date is 18.0 inches at Grand Marais (Cook County) in 1917.

Past Weather:

The coldest March 14th in history was in 1897. Over 50 Minnesota climate stations set record cold minimum temperatures on that date, many of -30°F or colder. With 20 to 30 inches of snow still on the ground, the daytime high temperatures did not warm up too much. The afternoon high temperature at Bemidji only reached -13°F.

A late winter storm brought heavy snows to many parts of Minnesota over March 13-14 of 1997. Many areas of the state reported 6-12 inches of snowfall from the storm and a few southeastern communities reported 15 to 21 inches. Many schools were closed on Friday, March 14 giving children a 3-day weekend.

March 14 of 2012 was the warmest in state history with over 120 long term climate stations reporting new daily high temperatures, many in the 70s F. Many areas also reported record warm overnight low temperatures as well. La Crescent saw a morning low of 55°F and Chanhassen 50°F. It was not surprising, as March of 2012 was the warmest in state history.

Outlook:

Mixed precipitation Friday night and into Saturday as a large low pressure system moves through the Midwest. Some southern areas will see thunderstorms and significant rainfall, and others may get a few inches of snow. Wind gusts will be strong, exceeding 30 mph and even 40 mph in some areas, bringing blizzard conditions early on Saturday to parts of western Minnesota. Cooler temperatures will prevail over the weekend, then moderate to warmer than normal temperatures for Monday and Tuesday, before another threat of rain and snow comes on Wednesday of next week.