Roller Coaster Temperature Pattern Continues:
Over a dozen climate stations reported a low temperature of -20 degrees F or colder on December 11th, with -30 degrees F reported at Isabella (Lake County). Furthermore on the 10th a number of places never saw the thermometer rise above zero, including Otter Tail which observed a high temperature that day of -4 degrees F. All but a handful of climate stations have recorded subzero low temperatures this week, in sharp contrast to the relatively mild temperatures that prevailed earlier in the month. A return to a milder temperature pattern is seen for much of the rest of December, so much so that the month may end up being warmer than normal overall, rather than the 9th cooler than normal month for the year 2019.Some areas up north have accumulated over 20 inches of snowfall this month, but the outlooks for the remainder of the month suggest less than normal snowfall. This outlook suggests that little more precipitation will be added by the end of the month to the very high annual precipitation being reported around the state for the year 2019. Over 50 climate stations have reported at least 45 inches of precipitation for the year, and at least 10 climate stations have reported over 50 inches. It is a foregone conclusion that 2019 will probably be the wettest year in history on a statewide basis, surpassing 1977 and 2016.
Weekly Weather Potpourri:
This week AGU-EOS reports on a recent study coordinated through the Max Planck Institute that reveals soil erosion acceleration began as a result of human activity over 4000 years ago. Many samples of lake sediments show this to be the case, primarily as a result of deforestation to make room for agriculture. Such acceleration continues today as agriculture develops in forested landscapes.Jonathan Erdman with the WeatherUnderground provides a wonderful perspective on the pitfalls of snow forecasting this week in an article on their web site. Snow is the most difficult meteorological element to forecast precisely, and Mr. Erdman delineates all the reasons that this is true, even with the modern technology we deploy.
MPR listener question
What is the difference between freezing rain and freezing drizzle?Answer:
Good question. The distinction between freezing rain and freezing drizzle is technically the droplet size. Drizzle consists of droplets which are 0.2 to 0.5 millimeters (.01 to .02 inches) in diameter. Rain droplets are larger diameters. Another important characteristic difference is that being of such a small size drizzle tends to be more uniformly dispersed and often appears to float around among air currents before it finally lands on the surface. It is most often very light and of little significance, generally recorded as only a trace in a rain gage for example. On the other hand, the larger rain droplets tend to fall in shafts of varying density. In the freezing form, both kinds of precipitation fall as liquid, but freeze on contact with subfreezing surfaces. December can be a month with a higher incidence of freezing drizzle and freezing rain.Twin Cities Almanac for December 13th:
The average MSP high temperature for this date is 27 degrees F (plus or minus 14 degrees F standard deviation), while the average low is 13 degrees F (plus or minus 15 degrees F standard deviation).MSP Local Records for December 13th:
MSP records for this date include: highest daily maximum temperature of 53 degrees F in 1891; lowest daily maximum temperature of -5 degree F in 1917; lowest daily minimum temperature of -21 degrees F in 1917; highest daily minimum temperature of 38 degrees F in 2015; record precipitation of 0.48 inches in 1975. Record snowfall is 6.3 inches in 1983.
Average dew point for December 13th is 10°F; the maximum dew point on this date is 44°F in 2014; and the minimum dew point on this date is -26°F in 1961
All-time state records for December 13th:
The state record high temperature for this date is 62 degrees F at Rochester (Olmsted County) in 1908 and at Lynd (Lyon County) in 1921. The state record low temperature for this date is -42 degrees F at Ada (Norman County) in 1901. The state record precipitation for this date is 1.92 inches at Hinckley (Pine County) in 1968. Record snowfall for this date is 12.8 inches at Hibbing (St Louis County) also in 1995.Past Weather Features:
Perhaps the coldest December 13th in state history was in 1901. Most areas of the state saw morning low temperatures of -20 degrees F or colder. Many areas in northern Minnesota were -30 degrees F or colder, while the high temperature at Ada only reached -25 degrees F.A slow moving winter storm brought heavy snowfall to the state over December 13-15, 1983. Many areas of the state reported 8 to 15 inches of snowfall, with over 17 inches reported at Two Harbors.
Outlook:
Cloudy to start the weekend, then becoming sunnier, but temperatures will continue cooler than normal for this time of year well into next week. It looks like it will be relatively dry as well until near the end of next week.
Comments