National Weather Service Weather Forecast Office

   Due to unseasonably persistent cold air in place, a storm system tracking to our south on Sunday and Sunday Night will produce snow over at least a portion of the local area, with the likelihood increasing that accumulating snow of at least several inches will be seen in some communities. 

  The likelihood of accumulating snowfall during the last couple weeks of March into April does diminish fairly quickly, however, it certainly can and does happen.  In Chicago, there have been 73 calendar days after March 20th with accumulating snow of 2 inches or more in the past 126 years.  That averages to a little over one late season two inch plus event every two years.  The most recent such day was April 5, 2009, where 2.1 in. fell.

   For Rockford, there have been 50 calendar days after March 20th with accumulating snow of 2 inches or more in the past 107 years (since 1906).  That averages to a little less than one event every two years.  The most recent late season calendar day with two or more inches of snow was March 21, 2008 when 4.7 in. fell.

• Chicago Snowfall Statistics
• Rockford Snowfall Statistics

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
619 PM CDT FRI MAR 22 2013 /719 PM EDT FRI MAR 22 2013/

...JUST HOW RARE ARE SPRING SNOW STORMS IN THIS REGION...

THE POTENTIAL EXISTS FOR AREAS SOUTH OF THE KANKAKEE RIVER TO SEE
A SIGNIFICANT LATE SEASON SNOW STORM SUNDAY. WHILE THERE ARE NO
FIRST ORDER OFFICIAL CLIMATE STATIONS IN THE NATIONAL WEATHER
SERVICE CHICAGO`S AREA OF RESPONSIBILITY DOWN THERE...A COUPLE OF
LONG TERM COOPERATIVE OBSERVER SITES DO HAVE FAIRLY COMPLETE LONG
TERM RECORDS.

FIRST...RENSSELAER...INDIANA HAS FAIRLY COMPLETE DAILY SNOWFALL
RECORDS DATING BACK TO 1908...THOUGH THERE IS A PERIOD OF TIME
DURING THE 1970S THAT THERE WAS MISSING SNOW FALL DATA. FOR THE
DATA THAT IS AVAILABLE...THERE HAVE ONLY BEEN 6 SNOW STORMS THAT
HAVE PRODUCED 6 INCHES OR MORE OF SNOW IN RENSSELAER AFTER MARCH
20TH...

RANK   SNOW     DATE
1)      8.5     MARCH 27, 1934
2)      8.3     APRIL 16-17, 1961
3)      8.0     APRIL 4, 1920
4)      7.5     MARCH 25-26, 1930
5)      7.0     APRIL 8, 1957
6)      6.0     MARCH 25-26, 2002

THE COOPERATIVE OBSERVATION STATION IN PONTIAC ILLINOIS HAS
SNOWFALL RECORDS DATING BACK TO THE 1903-04 WINTER...WITH VERY
LITTLE MISSING DATA. IN PONTIAC...THERE HAVE ONLY BEEN 9 SNOW STORMS
THAT HAVE PRODUCED 6 OR MORE INCHES OF SNOW AFTER MARCH 20TH...

RANK   SNOW     DATE
1)     12.0     APRIL 11, 1997
2)     10.0     APRIL 4-5, 1920
3)      9.5     MARCH 25-26, 1930
4)      7.0     MARCH 26, 1970
5)      7.0     APRIL 2, 1926
6)      6.0     MARCH 21, 1983
        6.0     APRIL 6, 1982
        6.0     MARCH 22, 1977
        6.0     MARCH 30-31, 1926

DATA COMPILED FROM THE MIDWEST CLIMATE DATA CENTER INDICATES THAT
ON AVERAGE AREAS SOUTH OF THE KANKAKEE RIVER GENERALLY AVERAGE
LESS THAN 2 INCHES OF SNOW FALL AFTER MARCH 20TH.

FOR CHICAGO...SNOW STORMS DURING THE LATE MARCH INTO APRIL ARE
SLIGHTLY MORE COMMON...THOUGH STILL RARE. HERE ARE THE TOP 10 SNOW
STORMS FOR CHICAGO AFTER MARCH 20TH...

RANK   SNOW     PCPN    DATE
1)     19.2     1.59    MARCH 25-26, 1930
2)     14.3     1.82    MARCH 25-26, 1970
3)     12.6     1.97    MARCH 30-31, 1926
4)     10.7     1.26    APRIL 1-2, 1970
5)      9.8     1.16    APRIL 2-3, 1975
6)      9.0     1.13    APRIL 6, 1938
7)      8.8     0.96    MARCH 21-22, 1992
8)      8.5     1.09    MARCH 21-22, 1932
9)      8.1     0.58    MARCH 28-29, 1964
10)     7.9     0.70    MARCH 22-23, 1965

NOTICE THAT THE LIQUID PRECIPITATION TOTALS FOR THESE SNOW STORM
TEND TO BE VERY HIGH...MEANING THAT THE SNOW THIS TIME OF YEAR
TENDS TO BE WATER LOADED AND VERY HEAVY. NOW IT IS POSSIBLE THAT
SOME OF THE PRECIPITATION LISTED DURING SOME OF THESE EVENTS FELL
AS RAIN...BUT EVEN STILL THE AMOUNT OF PRECIPITATION THAT FALLS
WITH BIGGER SNOW STORMS THIS TIME OF YEAR TENDS TO BE VERY LARGE.

NOTE: THE SNOW FALL TOTALS LISTED ABOVE ARE THE GREATEST SNOW
FALL TOTALS FOR 2 CONSECUTIVE CALENDAR DAYS. IT IS
POSSIBLE...THOUGH NOT LIKELY...THAT THERE COULD HAVE BEEN 2
DIFFERENT STORMS THAT PRODUCED THE SNOW FALL IN THE 2 DAY PERIOD.
HOWEVER...USING THE GREATEST 2 DAY SNOW FALL TOTALS INCREASES THE
LIKELIHOOD OF CAPTURING MOST OR ALL OF THE SNOW FALL FOR STORMS
THAT CROSS CALENDAR DAYS.

$$

IZZI