Reversal of January Temperatures:
The proverbial "January Thaw" (two or more consecutive days with daily high temperatures greater than freezing) for the Twin Cities has historically about an 80 percent probability of occurrence (about a 91 percent probability since 1980 with a pronounced urban heat island effect). This January it is happening to us with an exclamation mark! We may have up to 10 consecutive days with daily high temperatures above freezing if the forecast through January 26th verifies. In this context it would be the 5th longest such streak in the Twin Cities climate records surpassed only by 18 days in January 1944, 15 days in January 1942, 13 days in January 1919, and 11 days in January 1880 and 1909. (thanks to NOAA's Michelle Margraf and DNR-SCO's Pete Boulay for pointing this out).
Over 50 Minnesota climate stations have already reported daytime highs in the 40s F this week, including 48°F at both Grand Rapids and Forest Lake on the 18th. Some record high maximum and minimum temperatures may be reported in the coming days as well. Some nights will remain above the freezing mark, as for example Friday, January 20 when many lows ranged between 33°F and 35°F. BTW probably the warmest January night in Minnesota history was January 25, 1944 when the low temperature never fell below 40°F at Rochester, the Twin Cities, Fairmont, and Winona.
The end result of this long "January Thaw" period will likely place mean month January temperatures above normal, marking the 17th consecutive month with above normal temperature values around the state.
Soil Frost Depth:
According to measurements compiled by the DNR-State Climatology Office soil frost depths around the state currently range from 9 to 27 inches depending on snow cover and soil type. This is not unusual. Maximum frost depths are usually attained by late February, but the recent spell of mild weather should keep frost depths fairly stable through the end of this month. More details about soil frost depths can be found at the State Climatology Office web site.
New Seasonal Climate Outlooks:
The NOAA-Climate Prediction Center issued new seasonal climate outlooks this week. For the period from February through April they call for generally cooler than normal temperatures across most of Minnesota and the high plains states (North Dakota, Montana). This is based on dynamical and ensemble models and does not indicate a high level of confidence. The outlook for precipitation over this period is for above normal values from the Great Lakes Region (including Minnesota) westward to the state of Washington. This follows trend analysis.
Weekly Weather Potpourri:
Deke Arndt with NOAA-NCEI presents his analysis and interpretation of the significant weather and climate events of 2016 in a review article this week. It is well worth reading for relating the significance of these events to trends in the climate and the need for us to consider community-based resilience strategies and planning.
On one of the NOAA web sites you can now play an animation of global temperatures for the period 1880-2016 and see distinctly the areas of planet Earth that have grown warmer and peaked in the year 2016. It is worth taking a look at.
The US Climate Resilience Toolkit now features a variety of case studies of community actions which have helped to build resilience to climate change and climate variability. It contains many good ideas for consideration.
Using sediment cores scientists from the University of Arizona have reconstructed the precipitation climate of the Sahara Desert for the past 25,000 years. The data show that between 5000 and 11000 years ago the Sahara received about ten times more rainfall than it does today. This supported a different type of vegetation as well as a hunter-gatherer human culture.
A recent paper in the Earth & Space Science News documents efforts of German scientists to explain the amplified warming that has been measure in the Arctic Region of the Northern Hemisphere. It is a somewhat complicated picture as albedo (reflectivity) as well as the extent of sea ice play important roles.
MPR listener question:
I noticed on my Minnesota Weather Guide calendar that the record snowfall in the Twin Cities on January 20 and January 22 were both in 1982, with 17.1 and 17.2 inches respectively. Was that a single storm or a double whammy? Did that rank as one of the bigger snow events in Minnesota history?
Yes, I vividly remember those storms because of the huge snow drifts and snow loads imposed on thousands of roof tops around the Twin Cities. There were two distinct storms, one occurring on a Wednesday (Jan 20), the other on a Friday (Jan 22). The second storm brought blizzard conditions and dangerous wind chills besides heavy snow. Several deaths were associated with these storms and a number of roofs collapsed, some in rural areas killed livestock and poultry. Interstates I35 and I90 were both closed for a time.
Many daily snowfall records were set and snowfall totals for the two storms were astounding: Many climate stations reported over 30 inches for the two storms, while the Twin Cities reported a grand total of 37.4 inches. After the storms many climate stations also reported record snow depths. Hastings and Farmington both reported over 40 inches of snow depth. Snow plows piled the snow into such large hills at intersections that drivers could not see around corners. The Twin Cities ended up with over 46 inches of snowfall for January of 1982.
Twin Cities Almanac for January 20th:
The average MSP high temperature for this date is 24 degrees F (plus or minus 15 degrees F standard deviation), while the average low is 7 degrees F (plus or minus 15 degrees F standard deviation).
MSP Local Records for January 20th:
MSP weather records for this date include: highest daily maximum temperature of 52 degrees F in 1908; lowest daily maximum temperature of -17 degrees F in 1888; lowest daily minimum temperature is -32 degrees F in 1888; highest daily minimum temperature of 35 degrees F in 1921; record precipitation of 0.80 inches in 1982; and a record snowfall of 17.1 inches in 1982.
Average dew point for January 20th is 4 degrees F, with a maximum of 36 degrees F in 1921 and a minimum of -38 degrees F in 1985.
All-Time State Records for January 20th:
The state record high temperature for this date is 61 degrees F at Madison (Lac Qui Parle County) in 1944. The state record low temperature for this date is -57 degrees F at Embarrass (St Louis County) in 1996. State record precipitation for this date is 1.76 inches at Preston (Fillmore County) in 1988; and record snowfall is 17.1 inches at MSP in 1982.
Past Weather Features:
One of the worst winter storms from the harsh winter of 1916-1917 came over January 20-21, 1917. Rain, sleet, freezing rain, and snow fell across many parts of the state. Observers across the southern and central counties reported 10 to 24 inches of snow, with drifts as high as 6 feet.
By far the warmest January 20th in state history occurred in 1944 when nearly all areas of the state saw afternoon temperatures climb into the 40s F. Over 40 climate stations reported an afternoon high temperature of 50°F or greater, and a few spots reached 60 degrees F.
Record-setting heavy snow fell across much of the southern half of Minnesota on January 20, 1982. Many observers reported between 10 and 17 inches.....see the answer to the MPR listener question.
One of the most intense Cold Waves of the 1990s occurred on January 20, 1996. Arctic high pressure brought low temperatures down to record-setting levels across much of northern Minnesota where morning readings of -40°F or colder were common. Five climate stations were colder than -50°F and the temperature never rose above -22 degrees F at Red Lake Falls.
Warm and cloudy through the weekend and into next week. Chance for drizzle, rain or freezing drizzle on Saturday, and mostly dry on Sunday and Monday. Continued mild temperatures well into next week with a chance for mixed precipitation on Tuesday and Wednesday.