Champaign-Urbana set a record for their heaviest December snowfall total on record. The 20.4 inches of snow that has fallen so far in December surpassed the old record of 19.1 inches set in 1983.
The 5.0 inches of snow on Christmas Day clinched the December snowfall record. By the way, it was also the biggest snowfall on record for that date. It surpassed the old record of 3.8 inches that fell on December 25, 1944.
We have had measurable snow on the ground since December 4.
It has been persistently cold as well. The average temperature for December through the 27 is 21.3 degrees, the ninth coldest December on record. The forecast is for milder temperatures for the rest of the month so this December may slip a little in the rankings. Oddly, we only dropped below zero once, on December 9 with -1°F.
A complete listing of Champaign-Urbana observations are found here.
What happened to the rest of the 1983-84 winter? The snowfall total for January was only 5.6 inches. However, the heavy snow returned in February with 11.6 inches and 8.4 inches in March. Combined with the 0.2 inches that fell in November 1983, that winter season ended up with 44.9 inches.
As of December 21, Illinois remains 10.2 degrees below normal for the month. At 20.9 degrees, this is now the 5th coldest December since statewide records began in 1895. It could still move up or down in the ranking, depending on how the rest of December behaves.
Statewide precipitation stands at 1.06 inches of precipitation (rainfall plus the water equivalent of any snow).
Snowfall totals for the month ranges from less than 2 inches in far southern Illinois to over 14 inches in northwest Illinois (see map below). Right now the two spots with the most snowfall in the state for December are a CoCoRaHS site near Marseilles with 18.5 inches and a CoCoRaHS site near Champaign with 18.3 inches of snow.
From my web page on current conditions in Illinois, here is the breakdown by region within the state as well as the statewide numbers at the bottom for December 1-21.
12/01/2010 to 12/21/2010
Climate <------Temperature-----> <---------Precipitation--------->
Division Actual Normal Dev Actual Normal Dev Percent
Northwest 15.2 26.3 -11.0 1.44 1.45 -0.01 99
Northeast 17.0 27.9 -10.9 1.30 1.63 -0.33 80
West 21.4 29.7 -8.3 0.56 1.63 -1.07 34
Central 18.9 29.7 -10.8 1.13 1.76 -0.63 64
East 17.6 30.1 -12.4 1.53 1.75 -0.23 87
West-southwest 23.8 32.5 -8.6 0.56 1.91 -1.35 29
East-southeast 23.3 33.6 -10.2 1.23 2.04 -0.80 61
Southwest 26.2 35.7 -9.5 0.79 2.31 -1.52 34
Southeast 26.4 36.4 -10.0 0.93 2.43 -1.50 38
State 20.9 31.1 -10.2 1.06 1.86 -0.79 57
Dev means Deviation From Normal, Percent means Percent of Normal
The December 2010 snowfall in Champaign-Urbana is at 15.4 inches as of the morning of December 21. That makes it the 7th snowiest December on record.
19.1″ in 1983
18.5″ in 1981
18.1″ in 1973
18.0″ in 1909
17.4″ in 1977
15.7″ in 1950
15.4″ in 2010 (as of December 21)
14.7″ in 2000
14.0″ in 1990
13.3″ in 1915
Looking at the NWS forecast, we can still move up the ranks. Given the 6 inches of snow on the ground in C-U, the forecast for cold temperatures to persist, and the chance of snow on Christmas Eve means we have a very good chance of a white Christmas.
NOAA’s Climate Prediction Center has revised their winter forecast today. Their earlier outlook for December-February called for increased chances of above normal temperatures in the southern two-thirds of Illinois and above normal precipitation for all of Illinois.
However, December is already shaping up to be on the cold and dry side (see earlier post).
Now their outlook for January calls for equal chances of above, below, and near-normal temperature and precipitation in Illinois. It’s what I call a neutral forecast.
In their forecast for January-March, they call for an increased chance of above-normal precipitation in Illinois as well as much of the Ohio River Valley and Great Lakes region (see map below). Their temperature outlook remains neutral for Illinois for this period.
After such nice weather in October and most of November, real winter weather arrived in Illinois for December. The statewide average temperature for the first 14 days of December was 22.0 degrees, 10.6 degrees below normal.
The statewide average precipitation is 0.83 inches, 0.5 inches below normal.
Snowfall has been widespread across the state in early December. Snowfall totals range from less than an inch in far southern Illinois to over 10 inches in northwestern Illinois. See map below for snowfall totals for December 1-14, 2010.
The National Climatic Data Center has a web page that generates the snowfall climatology and extremes for any U.S. state except Hawaii (sorry).
From there you can pick a state and look at state-wide numbers like who had the greatest 1-day snowfall (24 inches at Coatsburg IL on Feb. 28, 1900) or the great snow depth (39 inches at Antioch on Jan. 16, 1979). You can also pull up more detailed station by station analysis of snowfall including averages and dates of the earliest and latest snowfall, etc.
The statewide average temperature for November 2010 was 43.4 degrees, which was 1.6 degrees above normal. That makes it the 26th warmest November since statewide records began in 1895.
By the way, the 2000’s are well represented in the list of warm Novembers. Their rank and year include: #1 (2001), #5 (2009), #10 (2004), #14 (2003), #16 (2005), and #17 (2006).
The statewide average precipitation for November was 3.2 inches, only 0.1 inches below normal. November was exceptionally dry until the long Thanksgiving weekend arrived. Rains from that period signaled the recovery of soil moisture around the state. See the earlier posts on this subject.
The highest monthly total precipitation in Illinois for November was 7.15 inches recorded at Mt Carmel. The highest daily temperature for November was 82 degrees recorded at Cairo on November 13. The lowest daily temperature for November was 12 degrees recorded at Mt Carroll on November 26.
The statewide average temperature for fall (September-November) was 55.4 degrees, 1.2 degrees above normal.
The statewide average precipitation for fall was 8.6 inches, 0.8 inches below normal. Widespread rains in early September and late November masked the long period in between with dry conditions. Note: these numbers are preliminary and subject to change as more data arrives.