Preliminary November climate summaryCold and dry describe the climate for November this year. Most observers report average monthly temperatures that range from 1 to 3 degrees F colder than normal. Extreme temperatures for the month ranged from 66 degrees F at Wheaton on the 14th to -11 degrees F at Roseau, Thief River Falls, and Orr on the 24th. General absence of full, sunny days, abundant cloud cover, and a high frequency of fog prevented daytime maximum temperatures from getting very high.
Most observers reported a drier than normal month as well, with less than a half inch being a common amount. In the western part of the state places like Milan and Madison reported less than a tenth of an inch. Northeastern and southeastern counties reported some above normal monthly precipitation with amounts ranging from 1 to 2 inches. Some wet spots in the state included Caledonia with 2.19 inches, Cannon Falls with 2.65 inches, La Crescent with 2.09 inches, and Preston with 1.90 inches. Most observers reported some snowfall as well, though usually just small amounts. Some of the larger monthly snowfall amounts were 9.0 inches at Marshall and Pipestone, 7.4 inches at International Falls, 7.9 inches at Kabetogama, 7.6 inches at Cook, 6.4 inches at Lamberton, and 6.0 inches at Hutchinson.
By the end of the month most areas soils were frozen to a depth of 4 inches, and many area lakes were showing thin ice on the surface.
Testing the 20/20 rule for December in the Twin CitiesSome older Minnesota citizens have told me about something they call the 20/20 rule. It goes like this, whenever you get 20 inches of snow during a winter month (Dec-Feb) you will likely also see a reading of at least -20 degrees F. I tested this idea with the Twin Cities climate record for the month of December, and sure enough it works pretty well. For the period from 1820 to 2012, I examined all Decembers when at least 20 inches of snowfall was measured or estimated. This has happened 14 times over the past 193 years (some of these are estimated in the Pioneer records).
|Year||December snowfall total (inches)||Lowest temperature
in degrees F
|1830||20.0(15 days with snow)||-26 F on the 21st|
|1849||30.0||-22 F on the 29th|
|1865||26.1||-26 F on the 21st|
|1879||20.0||-39 F on the 25th|
|1880||22.0||-27 F on the 28th|
|1902||24.0||-20 F on the 26th|
|1927||22.8||-15 F on the 31st|
-20 F on the 27th
-19 F on the 31st
(Stillwater reported -28 F and Forest Lake -31 F in Dec 1968)
0 F on the 27th
(-10 F at Stillwater, Farmington and Forest Lake, but otherwise a cloudy month)
-29 F on the 19th
-27 F on the 26th
-24 F on the 25th*
-8 F on the 13th
(Stillwater reported -17 F on Dec 14th)
*data taken from NWS headquarters at Chanhassen
With two exceptions, 1969 and 2010, the 20/20 rule appears to hold up pretty well. In the modern era the urban heat island of the Twin Cities is probably disrupting this rule.
Weekly Weather potpourriA strong winter storm with high winds and mixed precipitation disrupted Thanksgiving travel plans for many Americas along the East Coast on Wednesday this week. There were many airport cancellations and delays, along with snarled traffic patterns. With the additional rainfall from this storm, Asheville, NC set a new annual precipitation record with 65.66 inches in 2013.
Tropical Cyclone Lehar was bringing heavy seas and rains the eastern coastal regions of Indian this week. It was expected to dissipate over the weekend.
The weekly USA drought update from Brad Rippey of the USDA World Agricultural Outlook Board included these highlights:
-Well-placed storm systems continued to reduce the coverage of U.S. drought, with just 30.57% of the Lower 48 States in drought on November 26. This is a decline of 1.88 percentage points from a week ago and represents the smallest U.S. drought coverage since December 27, 2011.
-Based on the definitions of drought employed in the production the U.S. Drought Monitor, historical U.S. drought coverage should average near 20%. The last time contiguous U.S. drought coverage was below 20% was December 14, 2010.
MPR listener questionWhat are the all-time records for extreme temperature in Minnesota during the month of December?
Answer: The warmest ever in December was 73 degrees F at Beardsley and Milan on December 6, 1939. The last time 70 degrees F was reported in the state during December was December 1, 1998 when Chaska reported a 70 F reading. The coldest temperature ever reported in December was -57 degrees F at Pokegama Dam on New year's Eve, 1898. The most recent bitterly cold December temperatures were in 1993 (-50 F at Tower).
Twin Cities Almanac for November 29thThe average MSP high temperature for this date is 31 degrees F (plus or minus 11 degrees F standard deviation), while the average low is 17 degrees F (plus or minus 12 degrees F standard deviation).
MSP Local Records for November 29thMSP weather records for this date include: highest daily maximum temperature of 62 degrees F in 1998; lowest daily maximum temperature of -4 degrees F in 1875; lowest daily minimum temperature is -25 degrees F in 1875; highest daily minimum temperature of 50 F in 1998; record precipitation of 1.38 inches in 1991; and a record 12.6 inches of snow fell on this date in 1991.
Average dew point for November 29th is 18 degrees F, with a maximum of 57 degrees F in 1998 and a minimum of -24 degrees F in 1958.
All-time state records for November 29th
The state record high temperature for this date is 68 degrees F at Albert Lea (Freeborn County) in 1999. The state record low temperature for this date is -39 degrees F at Tower (St Louis County) in 1896. State record precipitation for this date is 2.85 inches at Farmington (Dakota County) in 1934; and state record snowfall for this date is 16.0 inches at Cambridge (Isanti County) in 1991.