If you are looking for fresh snow by Christmas morning or are curious about potential travel disruptions, the best chances for at least 1" of new snowfall early this week exist across the mountainous West, Great Lakes, and Northeast. Otherwise, temperatures this last full week of December will average above normal for much of the lower 48 states. Read More >
| Cold air had moved into the region during the night of February 4 and warmed little on February 5, with many temperatures at or below freezing as rain moved in late on the 5th. Rain intensity increased into the evening with a switch over to sleet occurring generally north of I-88, especially in the Rockford area. Roads were reported as very poor with a combination of ice and sleet on them. Further south through the I-80 corridor, freezing rain accumulation occurred throughout the evening. Ice accumulation between one tenth to a little over one quarter inch were reported with slick conditions on untreated surfaces. Rainfall amounts were heavier with liquid and liquid equivalent totals of 0.30" to 0.80". There were even embedded thunderstorms with the radar resembling a spring look to it! Due to some of the heavier rates limiting immediate ice accretion, true ice accumulations exceeding one quarter inch were patchy. |
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Photos
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| Photo courtesy of Larry in McHenry, IL. | Photo courtesy of Twitter follower Daltonize13 in Paw Paw, IL |
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| Photo courtesy of Twitter follower @MidwestStormChaser in Elgin, IL. | Photo courtesy of Twitter follower @MidwestStormChaser in Elgin, IL. | Photo courtesy of John Willis in DeKalb, IL. |
Ice & Sleet Totals
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| Ice Accumulations | Sleet Accumulations |
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE CHICAGO IL
448 PM CST WED FEB 6 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0849 AM FREEZING RAIN OHARE AIRPORT 41.98N 87.90W
02/06/2019 M0.03 INCH COOK IL ASOS
0848 AM FREEZING RAIN WHEELING 42.13N 87.92W
02/06/2019 M0.04 INCH COOK IL ASOS
0847 AM FREEZING RAIN DUPAGE AIRPORT 41.91N 88.25W
02/06/2019 M0.14 INCH DUPAGE IL ASOS
0847 AM FREEZING RAIN WAUKEGAN 42.36N 87.84W
02/06/2019 M0.28 INCH LAKE IL ASOS
0846 AM FREEZING RAIN ROCKFORD AIRPORT 42.20N 89.10W
02/06/2019 M0.13 INCH WINNEBAGO IL ASOS
SNOW FALL 0.8 INCHES.
0844 AM FREEZING RAIN SUGAR GROVE 41.76N 88.44W
02/06/2019 M0.19 INCH KANE IL ASOS
0800 AM FREEZING RAIN ELGIN 42.04N 88.28W
02/06/2019 E0.20 INCH KANE IL TRAINED SPOTTER
0800 AM FREEZING RAIN ELGIN 42.04N 88.28W
02/06/2019 E0.25 INCH KANE IL PUBLIC
0800 AM FREEZING RAIN MCHENRY 42.34N 88.27W
02/06/2019 M0.25 INCH MCHENRY IL PUBLIC
1200 AM SLEET ROCKFORD AIRPORT 42.20N 89.10W
02/06/2019 M0.8 INCH WINNEBAGO IL OFFICIAL NWS OBS
1100 PM FREEZING RAIN DEKALB 41.93N 88.75W
02/05/2019 E0.25 INCH DE KALB IL PUBLIC
ESTIMATED FROM ICE ACCUMULATION ON TREE
BRANCHES.
1040 PM FREEZING RAIN ROCKFORD AIRPORT 42.20N 89.10W
02/05/2019 M0.12 INCH WINNEBAGO IL ASOS
1039 PM FREEZING RAIN AURORA 41.76N 88.31W
02/05/2019 M0.13 INCH KANE IL ASOS
1037 PM FREEZING RAIN WHEELING 42.13N 87.92W
02/05/2019 M0.04 INCH COOK IL ASOS
1035 PM FREEZING RAIN DUPAGE AIRPORT 41.91N 88.25W
02/05/2019 M0.11 INCH DUPAGE IL ASOS
1034 PM FREEZING RAIN OHARE AIRPORT 41.98N 87.90W
02/05/2019 M0.03 INCH COOK IL ASOS
1032 PM FREEZING RAIN 1 WSW BEACH PARK 42.42N 87.87W
02/05/2019 M0.25 INCH LAKE IL ASOS
MEASURED BY THE WAUKEGAN ASOS.
0855 PM SLEET 4 NW CRYSTAL LAKE 42.28N 88.37W
02/05/2019 M0.4 INCH MCHENRY IL CO-OP OBSERVER
0830 PM FREEZING RAIN ROUND LAKE 42.35N 88.09W
02/05/2019 M0.15 INCH LAKE IL PUBLIC
Science
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| A simple breakdown of precipitation types. Freezing rain and sleet require warm air atop cold air. This allows for full melting of snow and then the cold air allowing re-freezing either in contact with the surface (freezing rain) or before reaching the ground into ice pellets (sleet). | NWS Quad Cities 12 pm weather balloon launch data. This depicts the atmosphere before the precipitation had moved in and is why still a dry layer is present. Note the warm nose aloft and the strong south winds which are key to keep the layer warm as it begins to moisten. | NWS Quad Cities 6 pm weather balloon launch data. Here the moistened atmosphere is seen with a very high precipitable water for February of 0.87". The warm air aloft (6°C) is still present, sustained by over 50 kt winds in what is referred to as a low-level jet. The cold layer near the surface in this sounding is too shallow to support sleet so freezing rain was occurring in the Quad Cities and points east. Further to the north, such as near Rockford, this near-surface cold layer was deep enough for sleet. Also note some steepened lapse rates that helped support updrafts strong enough for charge separation and lightning. |
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Media use of NWS Web News Stories is encouraged! Additional recaps can be found on the NWS Chicago Science & Past Events Page. |
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