How February and This Winter Stacked Up in Illinois

Here are the time series plots of the statewide average temperature for February and winter (December-January-February) from 1895 to present (source: NOAA NCDC).

February

In the first plot, I have a red box around the temperature for 2014 and 2015. The only other time that we had a pair of extremely cold Februarys was 1978 and 1979. All the other cold Februarys were one-off events. According to NCDC, the statewide average temperature for February 2015 in Illinois was 19.5 degrees and the 9th coldest on record. Last February was nearly identical at 19.4 degrees.

plot1Winter

Continue reading “How February and This Winter Stacked Up in Illinois”

Last Below Zero Weather of the Season? I Hope.

Here are the lows this morning, courtesy of the National Weather Service office in Lincoln. Areas in blue were below zero. Champaign-Urbana reached -9 degrees, breaking the old record of 4 degrees set in 1899.

min_temp_small

Of course, widespread snow cover (map below), clear skies, and calm winds were contributing factors in the hopefully last round of below-zero weather this season. nsm_depth_2015030605_Midwest

24 HOUR MINIMUM TEMPERATURE DATA IN DEGREES FAHRENHEIT,
FOR ILLINOIS AND THE SURROUNDING STATES, INCLUDING
24-HR DATA THROUGH 7 AM, FRIDAY MARCH 6, 2015.

 
  ILLINOIS 

    DANVILLE AIRPORT                      -10
    ELIZABETH                             -10
    FREEPORT                              -10
    MCHENRY                               -10
    ROCHELLE AIRPORT                      -10
    CHAMPAIGN WILLARD AIRPORT              -9
    DECATUR AIRPORT                        -9
    SIDELL 5NW                             -9
    STERLING AIRPORT                       -9
    PAW PAW 2NW                            -7
    WATSEKA                                -7
    MATTOON AIRPORT                        -6
    OGDEN                                  -6
    PANA SEWAGE PLANT                      -6
    PAXTON 2WSW                            -6
    ALTONA                                 -5
    AURORA AIRPORT                         -5
    DIXON                                  -5
    DWIGHT                                 -5
    LINCOLN NWS                            -5
    NEOGA 4NW                              -5
    ROBINSON WTYE                          -5
    ROCHELLE                               -5
    ROCKFORD AIRPORT                       -5
    ROSICLARE                              -5
    WAUKEGAN AIRPORT                       -5
    BARRINGTON 3SW                         -4
    EFFINGHAM 3SW                          -4
    KEWANEE                                -4
    PARIS SEWAGE PLANT                     -4
    RAMSEY                                 -4
    SULLIVAN 3S                            -4
    MONMOUTH                               -3
    MUNDELEIN 4WSW                         -3
    TUSCOLA                                -3
    BROOKPORT DAM                          -2
    CARBONDALE AIRPORT                     -2
    CHICAGO DUPAGE AIRPORT                 -2
    COAL CITY 4NNW                         -2
    KANKAKEE                               -2
    LACON AIRPORT                          -2
    PRAIRIE CITY 2S                        -2
    GRAND CHAIN DAM                        -1
    MINONK                                 -1
    MORRIS                                 -1
    MT VERNON                              -1
    OLNEY 2S                               -1
    BLOOMINGTON 5W                          0
    CHICAGO OHARE AIRPORT                   0
    GALESBURG                               0
    MOLINE AIRPORT                          0
    OTTAWA 5SW                              0
    SMITHLAND LOCK AND DAM                  0
    SPRINGFIELD CAPITAL AIRPORT             0
    WINDSOR SEWAGE PLANT                    0
    ELGIN                                   1
    JOLIET LOCK AND DAM                     1
    LAWRENCEVILLE-VINCENNES AIRPORT         1
    MACOMB AIRPORT                          1
    PERRY                                   1
    SPRINGFIELD NE                          1
    AURORA                                  2
    CASEY                                   2
    CHICAGO BOTANIC GARDENS                 2
    GLADSTONE LOCK AND DAM 18               2
    JACKSONVILLE                            2
    NEW BOSTON LOCK AND DAM 17              2
    NORMAL 4NE                              2
    PARK FOREST                             2
    WINCHESTER                              2
    GRIGGSVILLE                             3
    PEORIA INTERNATIONAL AIRPORT            3
    RUSHVILLE 4NE                           3
    WHEATON                                 3
    CHICAGO WHEELING AIRPORT                4
    JERSEYVILLE 2SW                         4
    PITTSFIELD                              5
    BENTLEY                                 6
    CHICAGO MIDWAY AIRPORT                  6
    NASHVILLE                               7
    QUINCY AIRPORT                          7
    QUINCY LOCK AND DAM 21                  8
    KASKASKIA LOCKS                        10
    CAHOKIA AIRPORT                        14

A Weak El Nino Has Arrived, Another Winter Storm for Southern Illinois

1680v1_20150305-ElNino_arrives_1200
El Niño Arrives in 2015. This image shows the average sea surface temperature for February 2015 as measured by NOAA satellites. The large area of red (warmer than average) can be seen extending through the equatorial Pacific. (Credit: NOAA)

Today the National Weather Service reported that the long-awaited El Niño has arrived in the Pacific Ocean. El Niño occurs when we have above-average temperatures in the Pacific Ocean along the equator. It alters the Pacific weather pattern, which in turn alters our weather patterns over the US. The NWS forecasters say “it is likely (50 to 60 percent chance) that El Niño conditions will continue through summer. ” Due to the weak nature of this event, they are not expecting widespread or strong impacts from this event.

In other news, far southern Illinois was hit this week with another winter storm that passed through Arkansas; southeastern Missouri;  southern Illinois, Indiana, and Ohio; as well as most of Kentucky and points beyond. Some of the largest snowfall totals from this event include Grand Chain Dam with 10.0 inches and Brookport Dam with 9.0 inches.

snow-south

Winter Finishes Cold and Snowy in Illinois

The statewide average temperature for the three winter months of December, January, and February in Illinois was 26.1 degrees, 7.5 degrees below average. While cold, it was not nearly as cold as last winter’s 21.7 degrees. This winter ranks as the 30th coldest on record.

winterThis winter started off mild with an average December temperature of 33.9 degrees, 4 degrees above average.  The average temperature in January was 25.7 degrees, only 0.7 degrees below average, and the average in February was 18.6 degrees, 12.3 degrees below average. See figure to the left, click to enlarge. Last winter, all three months were well below average.

Snowfall

Snowfall was above average for the winter from December through February. Most of that fell in February. December was snow-free for most of the state except in the far west. Snowfall was common in January but below average except for a band across northern Illinois. Major snows occurred in February to bring up the winter snowfall totals across the state. Above-average snowfall occurred across northern and western Illinois as well as far southern Illinois. The maps below show the observed amounts and departure from average.

map2map3

Precipitation

map1The average precipitation for December-February was 4.97 inches, 1.85 inches below average. In fact, most of the Midwest received below-average precipitation this winter (figure left). Precipitation is a measure of both rainfall and the water content of any snow. While we received above-average snowfall, the water content of that snow was not always great. In a typical year we can get rain in winter, but not so much this winter. This kind of precipitation deficit would be a concern during the growing season. However, in winter the water demand is low.