Late Season Snowfall in Chicago and Rockford

Gino Izzi of the NWS office in Romeoville rounded up these statistics for late season snowfall in Chicago and Rockford…

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
1128 AM CDT FRI MAR 25 2011 /1228 PM EDT FRI MAR 25 2011/

...LATE SEASON SNOWFALLS...

NOTHING SAYS SPRING TIME IN ILLINOIS MORE THAN TEMPERATURES IN THE
20S AND GRAY CLOUDY SKIES...BUT HISTORICALLY SPEAKING IT MAY BE A
BIT TOO SOON TO STOW AWAY THOSE SHOVELS. IN FACT...PORTIONS OF
MISSOURI AND DOWNSTATE ILLINOIS ARE SEEING SNOW THIS MORNING. SO
HOW COMMON IS IT TO SEE SHOVEL-ABLE SNOW IN OUR AREA THIS TIME OF
YEAR?

IN CHICAGO...54 OF THE PAST 139 YEARS (OR ABOUT 39%) HAVE HAD AT
LEAST ONE DAY WITH AN INCH OR MORE OF SNOWFALL ON OR AFTER MARCH
25TH. IN FACT...17 OF THOSE YEARS HAD MULTIPLE DAYS WITH OVER AN
INCH OF SNOWFALL INCLUDING 6 DAYS WITH OVER AN INCH OF SNOW BACK IN
1926! HERE ARE SOME OF THE RECENT LATE SEASON (AFTER MARCH 25TH)
CHICAGO SNOWFALLS...

SNOWFALL    DATE
 3.0     4/11/2007
 3.0     4/ 7/2003
 2.1     4/ 5/2009
 1.9     3/27/2008
 1.6     4/ 7/2000
 1.2     3/29/2009

HERE ARE THE TOP 10 BIGGEST LATE SEASON SINGLE DAY SNOWFALL TOTALS
FOR CHICAGO...

RANK   SNOW      DATE
 1    13.6    3/25/1930
 2     9.4    4/ 5/1982
 9.4    4/ 2/1975
 4     9.0    4/ 6/1938
 5     8.9    3/26/1970
 6     8.2    4/ 1/1970
 7     7.8    3/30/1926
 8     7.7    3/29/1954
 9     7.1    3/29/1964
10     6.6    3/26/1934

IN ROCKFORD...47 OF THE PAST 118 YEARS (OR ABOUT 40%) HAVE HAD DAYS
WITH AN INCH OR MORE OF SNOWFALL ON OR AFTER MARCH 25TH. OF THOSE
YEARS...10 HAVE HAD MULTIPLE DAYS WITH OVER AN INCH OF SNOW
INCLUDING 4 DAYS IN 1970 AND 1926. HERE ARE SOME RECENT LATE SEASON
ROCKFORD SNOWFALLS...

SNOWFALL    DATE
 1.9     4/11/2007
 1.8     3/29/2009
 1.2     4/ 7/2000
 1.1     4/ 1/2002
 1.0     4/12/2007

HERE ARE THE TOP 10 BIGGEST LATE SEASON SINGLE DAY SNOWFALL TOTALS
FOR ROCKFORD...

RANK   SNOW      DATE
 1    13.5    3/31/1926
 2    10.4    3/29/1972
 3     7.0    4/18/1912
 4     6.3    4/ 5/1982
 5     6.0    4/ 6/1938,  6.0    3/25/1933
 7     5.0    3/29/1954
 8     4.8    3/29/1964
 9     4.6    4/ 2/1975
10     4.5    4/ 2/1936,  4.5    3/28/1894

WHILE NO BIG SNOWS ARE CURRENTLY IN THE FORECAST FOR THE REGION...IT
IS WORTH NOTING THAT LATE SEASON SNOWS ARE NOTORIOUSLY DIFFICULT TO
PREDICT MUCH IN ADVANCE. CURRENT INDICATIONS ARE THAT THE COLD AIR
OVER THE AREA NOW WILL REMAIN IN PLACE THROUGH THE WEEKEND INTO
EARLY NEXT WEEK.

$$

IZZI

A Cold and Snowy Winter in Illinois

For anyone who lives in Illinois, it will come as no surprise that we were colder and snowier than normal this winter. The statewide average temperature for December-February was 24.9 degrees. That is 3.3 degrees below normal and the 17th coldest December-February since statewide record began in 1895. The coldest December-February in Illinois was 1977-78 with 19.6 degrees.

Snowfall for December-February ranged from 15 inches in southern Illinois to over 45 inches in northern Illinois (see maps below). According to the Lincoln NWS office, Peoria reported its snowiest December-February on record with 52.5 inches while Springfield reported its fifth snowiest December-February with 34.2 inches. According to the Chicago NWS office, Rockford reported its third snowiest December-February with 51.2 inches and Chicago reported its fifth snowiest December-February with 56.3 inches.

Precipitation (both rainfall and the water content of any snow) was near-normal. The statewide average precipitation was 6.90 inches, only 0.14 inches below normal.

Climatologists define winter as the months of December, January, and February because it lines up better with the kinds of weather we expect to see in winter. It’s better than the December 22 to March 22 definition, which is based on the winter solstice and the vernal equinox. In many cases in Illinois, we have already had several doses of winter weather by December 22 and winter weather is fading away once March arrives.

 

December 2010 to February 2011 snowfall.
December 2010 to February 2011 snowfall departure from normal.

Tenth Wettest February for Illinois

The statewide average precipitation in Illinois for February was 3.39 inches, 1.46 inches above normal and the tenth wettest February since statewide records began in 1895. Precipitation includes rainfall and the water content of any snow (and freezing rain, sleet, snow pellets as was the case in February). See maps below (click to enlarge). The highest monthly precipitation total in Illinois was 7.05 inches in Paris.

Snowfall was above normal in February across much of Illinois thanks to the February 1-2 winter storm.  Snowfall totals for the month ranged from just under 4.5 inches in southeastern Illinois to over 20 inches across much of northern Illinois. The highest monthly snowfall total in Illinois was 30.5 inches in Spring Grove.

Some outstanding monthly snowfall totals include Chicago with their snowiest February on record with 29.0 inches; Rockford with their fifth snowiest February on record with 20.2 inches, Peoria with their second snowiest February on record with 20.9 inches, and Springfield with their fourth snowiest February on record with 16.5 inches.

The statewide average temperature in Illinois for February was 29.5 degrees, 0.7 degrees below normal. The highest temperature for February in Illinois was 78 degrees in Waterloo on February 21. The lowest temperature for February was -22 degrees in Elizabeth on February 10.

February 2011 precipitation.
February 2011 precipitation departure.
February 2011 snowfall.
February 2011 snowfall departure.