Warm/Wet Trends in December

Warm/Wet Trends in December:

Since 2004 wetter than normal Decembers have been a Minnesota climate signature. Thirteen of the 17 years have brought abundant precipitation to the state in December. Over the same period of time (17 years) eleven have brought warmer than normal temperatures during December, with the warmest December in state history in 2015.

This week’s weather clearly reminded me of these trends as temperatures have been averaging 10 to 15°F about normal and abundant precipitation, both rain and snow has been persistent around the state. With daily temperatures reaching into the mid 30s F to low 40s F across the state, much of the precipitation this week has been measured as rainfall, especially in southern counties. Over Tuesday through Thursday, many climate stations have reported precipitation totals ranging from 0.50 inches to 1.25 inches. Brimson in St Louis County has reported well over 2 inches.

In central and northern areas of the state observers commonly reported 4 to 8 inches of snowfall. Many climate stations set new daily snowfall records this week, including:

For December 14th:
6.8 inches at Long Prairie (Todd County)
5.0 inches at Milaca (Mille Lacs County)
5.8 inches at Brainerd (Crow Wind County)
8.0 inches at Georgetown (Clay County)

In northeastern Minnesota snowfall quantities were record-setting too, with many climate stations reporting 10 inches for more on a daily basis. Some of the new daily snowfall records reported for For December 15th included:
10.0 inches at Ely and Floodwood
10.8 inches at Duluth National Weather Service
12.0 inches at Tower
12.2 inches at Embarrass
15.0 inches at Silver Bay
15.4 inches at Brimson

The 15.4 inches on December 15th at Brimson (St Louis County) set a new all-time state record snowfall total for that date, replacing 14.6 inches at Rockford (Wright County) in 1996. Many areas from Duluth north to Grand Portage reported storm total snowfall amounts ranging from 20 to 29 inches (at Finland). The Minnesota State Climatology Office provide a good storm summary on their web site.

Dramatic Moisture Rebound in Northern MN:

In the late autumn of 2021 north-central and northeastern Minnesota counties were in the grip of Extreme Drought. But the year 2022 has brought a remarkable turn-around to this situation as abundant precipitation has bee the year-long trend in that region of the state (in contrast to the south and west where Drought took a foothold this year). Some of the following climate stations are reporting one of their wettest years in history, and we still have half a month to go.
International Falls reports 34.87 inches (wettest in history)
Grand Marais reports 39.42 inches (2nd wettest in history)
Wolf Ridge ELC reports 40.74 inches (2nd wettest in history)
Gunflint Lake reports 34.15 inches (2nd wettest in history)
Grand Portage reports 39.00 inches (3rd wettest in history)
Tower reports 37.59 inches (3rd wettest in history)

Weather Potpourri:

This week’s AGU-EOS Bulletin features an article about increasing precipitation in the Arctic region of the Northern Hemisphere. Of interest to many atmospheric scientists is the finding that rainfall is increasing, as well as snowfall. All climate trends for temperature and moisture are upward since the 1950s.


The BBC Weather Center produced an interesting video this week about how the winter season in the United Kingdom has been altered in recent decades because of climate change. The number of frosty days has declined significantly as have the days with snowfall.


A new article in the Proceedings of the National Academy of Science describes the most plausible explanation for the differences in storminess between the Northern Hemisphere and the Southern Hemisphere. Lead author is Dr. Tiffany Shaw of the University of Chicago. The primary drivers of increased storminess in the Southern Hemisphere are the lack of numerous mountain ranges and of the stronger imbalance of surface energy flux due to ocean circulation.

MPR listener question:

Well, with the snowfall still ongoing after three days here in Two Harbors we are wondering what the record snowfall is for the month of December in Minnesota? Thought that you would know.

Answer:

Indeed, it has been very abundant this week in your area! The all-time state record total snowfall for the month of December is 58.7 inches in 2021. Observers near Two Harbors reported 55-56 inches for the month in December of 2013. So these extreme snowy Decembers are of recent vintage.

Twin Cities Almanac for December 16th:

The average MSP high temperature for this date is 28 degrees F (plus or minus 13 degrees F standard deviation), while the average low is 15 degrees F (plus or minus 13 degrees F standard deviation).

MSP Local Records for December 16th:

MSP records for this date: highest daily maximum temperature of 58 degrees F in 1939; lowest daily maximum temperature of -5 degrees F in 1876; lowest daily minimum temperature of -22 degrees F in 1876; highest daily minimum temperature of 35 degrees F in 1889; record precipitation of 0.93 inches in 1894. Record snowfall is 7.0 inches in 2000.

Average dew point for December 16th is 9°F; the maximum dew point on this date is 43°F in 2001; and the minimum dew point on this date is -25 degrees F in 1963.

All-time state records for December 16th:

The state record high temperature for this date is 65 degrees F at St Peter (Nicollet County) in 1939. The state record low temperature for this date is -39 degrees F at Pokegama Dam (Itasca County) in 1903. The state record precipitation for this date is 2.57 inches at Gunflint Lake (Cook County) in 1984. Record snowfall is 14.0 inches at Farmington (Dakota County) in 1940.

Past Weather:

The warmest December 16th came in 1939 when 20 climate stations reported afternoon temperatures of 60° or greater. It was as warm as 55°F at Moorhead in the Red River Valley, a record high temperature for them.

A strong winter storm brought heavy snowfall to central and northern Minnesota over December 15-16 of 1940. Many climate stations reported over 10 inches of snow. In southern Minnesota where 12 to 17 inches of snow fell and winds whipped the snow into huge drifts schools were closed on Monday the 16th.

An Arctic cold air mass brought record-setting low temperatures to Minnesota on December 16, 1963. Subzero temperatures prevailed in every corner of the state. Many northern communities reported morning lows of -30°F or colder. The afternoon high temperature at Campbell (Wilkin County) only reached -10°F.

Outlook:

Lingering chance of snow flurries in northern Minnesota for Saturday, mostly cloudy elsewhere. Clearing skies for Sunday but much colder. Temperatures will be well below normal in many areas starting on Sunday and lasting all of next week. There will be another chance for snow on Wednesday. Many nights of subzero temperature readings are ahead of us.