<%@LANGUAGE="JAVASCRIPT" CODEPAGE="1252"%> December 2009 Saint Cloud Weather Summary
Saint Cloud State University logo Earth and Atmospheric Sciences Department
Saint Cloud Forecasts
National Weather Service logoNWS SCSU Big C logo SCSU/Weisman
SCSU Home
SCSU NWA Chapter
Weisman Home
Climate
Weather
Making a Forecast
Alumni
Research
Courses
Handbook
Eighth Northern Plains Winter Storm Conference: Coming October 28-29, 2013 in Saint Cloud!

Return to Daily Statistics by Month Table

St. Cloud 2009 Year at a Glance


Top of Page
(December 2009 Summary)

Precipitation

Temperature

Snowfall

Saint Cloud Weather Summary for December 2009 and Annual Weather Summary for 2009

Roller Coaster Second Half of 2009 Ends With Notable Snowstorm

Major Christmas Storm Produces 7th Snowiest December

Since the end of summer, St. Cloud's weather has been on a roller coaster with each month's weather notably different than the month before. In December, however, there were multiple pattern changes, producing a cold first half of the month, then a warm period through Christmas, including the biggest snowstorm in 18 years. The net result was the 7th snowiest December in St. Cloud records with a total of 18.3 inches. The normal December snowfall is 8.6 inches.

More than two-thirds of the snowfell came during an odd December 23-26 snowstorm. This storm set several records for daily snowfall in Minnesota, mainly because there haven't been many large snowstorms in late December, and produced several snowfalls in the 12-16 inch category. However, the impact of the storm was eased by the spreading out of the snowfall over a four-day period. The worst impacts of the storm were in the Dakotas, Nebraska, Iowa, and Kansas where wind blown snow closed many roads and in Oklahoma City, where 14 inches had a great impact. In Minnesota, Duluth got the most snow with 24.4 inches.

In St. Cloud, this snowstorm did set a daily snowfall record on December 24, but there were no more than 4.8 inches falling on any day. Still, the 12.7 inches ended being only the 16th storm producing at least a foot in St. Cloud, and the first since the Halloween blizzard of 1991. A survey of the last 11 days of December also showed that this was arguably the heaviest late December single storm in St. Cloud history. The total of 12.7 inches falling during the last 11 days of December was the fourth highest amount of late December snow since St. Cloud snowfall records began in 1893. This amount was within half an inch of second place, but the most fell in during three storms last December. The 14.0 inches in late December 2009 were just part of St. Cloud's fourth snowiest December (23.0 inches).

In early December, there were 5 small snowfalls in the first 9 days of the month, producing a snow cover by December 9. This was later than the first day of persistent snow cover of 2007 (December 2) or 2008 (December 6). Both of the last two years have had long periods of continuous snow cover that lasted well into March (119 days in 2007-2008; 102 days in 2008-2009).

Cold Weather Only Lasts Half Of December, Producing Normal December Temperatures

Temperature-wise, December began with one last lingering day of lingering November warmth, but normally cold air moved in on the 2nd, followed by temperatures typical of January that dominated most of the first two-thirds of the month. During December 4-18, thirteen of the fifteen days were colder than normal with six days more than 10 degrees colder than normal. The average December 4-18 temperature was 8.9°F (high 16.5°F; low 1.3°F), more typical of January than December. However, the snowier late December weather came with a series of mild nights and a couple of days with the temperature near freezing during the snowstorm. On December 25, the high temperature climbed to 35°F and the low was only 30°F. This warmth produced an average December 25 temperature within a degree of the record average temperature of 34 degrees. The average temperature for the rest of December was 19.7°F (high 25.6°F; low 13.7°F), a high temperature typical of December, but a low temperature typical of late November. Overall, the December average temperature was 14.4°F, exactly normal for the month.

Liquid Precipitation Above Normal, Thanks to Late December Snow

All of the precipitation during December in St. Cloud took the form of snow, but the water contained in that snow was 1.31 inches, 0.62 inches higher than normal. Most of that liquid fell during the December 23-26 snowstorm as 0.91 inches were recorded at the St. Cloud Airport and 1.27 inches at St. Cloud State University.

Cold Weather Pattern for the New Year

Behind the late December storm, very cold air pushed into Minnesota. The combination of clear sky and deep snow cover is very effective at making conditions cold because:

  1. The sun is low in the sky (20 degrees above the horizon at best), so the atmosphere has a better chance to dilute the sun's energy. (Compute sun angle from the US Naval Observatory).
  2. There isn't much solar energy coming in. We have less than 9 hours of daylight, so the loss of energy by the ground to space on a clear night dwarfs the amount of solar energy available to absorb by the ground. (Get sunrise and sunset times from the US Naval Observatory).
  3. Snow cover reflects nearly all of the energy reaching the ground back to space. (see the latest snow cover maps from NOHRSC)

One cold high pressure is over Minnesota this morning, producing St. Cloud's first -20 low of the 2009-2010 winter and possibly producing the first -40 temperatures of the year in northeastern Minnesota, as you can see on the UCAR Minnesota surface chart loop. However, there's another cold high parked in the Yukon and Nunavut. With our flow expected to remain from the northwest during the next week, the cold air over us now will probably be reinforced to some degree.



Return to top of page
All climate data provided courtesy of NOAA/NWS
National Weather Service logoNOAA logo
and Minnesota Climatology Working Group, including the Minnesota State Climatologist's Office, University of Minnesota-Saint Paul Campus.

Interested in an undergraduate degree in meteorology?


Send comments to: raweisman@stcloudstate.edu
Last updated: Saturday, January 2, 2010 12:40 PM
Background courtesy of aaa-backgrounds.com