Low pressure tracked from near Kansas City during the evening of November 20th into the Ohio River Valley by the morning of November 21st. Since the atmosphere was initially warm, the precipitation started as rain across much of the area, then gradually changed to snow during the morning of the 21st as colder air arrived in the wake of the storm system.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS ILX wrote it up.
Low pressure tracked from near Kansas City during the evening of November 20th into the Ohio River Valley by the morning of November 21st. Since the atmosphere was initially warm, the precipitation started as rain across much of the area, then gradually changed to snow during the morning of the 21st as colder air arrived in the wake of the storm system. The highest accumulations occurred where rain changed to snow fastest, generally along and north of the I-74 corridor. 4 to 6 inches of snow fell along a Peoria to Watseka line...and as much as 8 to 10 inches accumulated along and northwest of a Galesburg to Bradford line.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Lincoln, IL wrote its last area forecast discussion before the first event at Nov 20, 8:41 PM CST, 19 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Lincoln IL 841 PM CST FRI NOV 20 2015 .UPDATE... ISSUED AT 830 PM CST FRI NOV 20 2015 Forecast looking on track for the rest of this evening with the rain slowly spreading into east central IL, with a changeover to snow occurring over our far northern counties. 00z ILX sounding continues to indicate a very dry air mass in place below 700 mb early this evening. Strong low and mid level warm advection pattern ahead of the main upper level wave has produced this lead band of rain with isolated convection seen over parts of east central Missouri. Forcing aloft is sufficient enough to moisten the low levels rather quickly this evening producing some significant evaporative cooling as the temp-dew point spreads were rather large this afternoon. The rain has gone over to snow in Altona in far northern Knox county with a temperature there of 32 degrees, with most other locations to the south still well in the 40s. In fact, the latest surface analysis showing the dew points over parts of west central and central Illinois were rising into the lower 30s over the past few hours. Quick look at the 00z Nam-Wrf suggests the strong forcing/lift associated with the amplified 500 mb trof will be during the morning hours of Saturday. Most of the short term model soundings were rather warm in the low levels of the atmosphere thru about 09z before the stronger forcing coincides with the deeper moisture to produce a steady precip pattern over our area. Low level flow until then will be out of a southeast to east direction, not very conducive to a quick changeover to snow. However, after 09z, the RAP soundings suggest winds back more into a northeast to north direction which would suggest a quick change to snow further east and southeast of the IL River valley. That is what is currently reflected in the ZFP, so other than some minor tweaks to precip timing and with hourly temperatures, no major changes being made to the grids. Have already sent out an update earlier this evening to address the precip timing out west this evening, so no additional ZFP update will be needed at this time. && .SHORT TERM...(Tonight) ISSUED AT 300 PM CST FRI NOV 20 2015 20z/2pm surface analysis continues to show a ridge of high pressure extending from the Upper Midwest into the Ohio River Valley, while a 1010mb low gets organized over south-central Nebraska. Light snow has developed in advance of the low as far east as central Iowa: however, it is having a hard time spreading further eastward due to a dry airmass in place beneath the ridge axis. Current surface dewpoints across the KILX CWA are only in the teens and 20s, and forecast soundings suggest the airmass will only slowly moisten from the top-down as the day progresses. 19z run of the Rapid Refresh model shows light precipitation arriving in the Illinois River Valley between 6 and 9pm, then gradually spreading eastward to the Indiana border toward dawn Saturday. If this solution pans out, much of the Wabash River Valley will remain dry through the entire night. Precipitation type will be a bit tricky, as surface temperatures will initially be warm enough to support rain. However, as evaporative cooling of the dry mid/low levels takes place, a transition from rain to snow will occur from mid evening through the overnight hours. Based on NAM/Rapid Refresh soundings, will include a mix of rain/snow as far east as a Bloomington to Springfield line by midnight...then further south/east to a Danville to Taylorville line by dawn. The mixed precip will become all snow along/north of a Rushville to Bloomington line overnight. Snowfall totals through 12z Saturday will range from around 1 inch along a Rushville to Bloomington line...to 2 to 3 inches north of the Peoria area. Since this will be the first snow of the upcoming winter season, decided to add another row of counties to the Winter Weather Advisory to include Fulton, Tazewell, and McLean. .LONG TERM...(Saturday through Friday) ISSUED AT 300 PM CST FRI NOV 20 2015 Complicated forecast continuing into tomorrow morning with the winter storm continuing the snow fall roughly north of a line from Rushville to Champaign...ending from west to east by noon. Areas in central and southeastern Illinois will see a slow end to the rain as well as colder air moves in behind the system. Whereas the bulk of the snow will fall before 6 am, some additional accumulations will fall through noon, particularly along and north of I-74 from Galesburg to Bloomington/Normal. Winds will pick up out of the northwest becoming somewhat breezy and dropping the temperatures through the afternoon. Some blowing snow will be possible, especially in open areas...but the majority of the snow will be heavy and wet early on, and affected by partial melting. Cold air moving into the region overnight with clearing skies, and by Sunday morning, temperatures will drop into the single digits and teens. Brisk winds in the morning will result in wind chills dropping to -3C to 11C range. Sundays high temperatures will struggle into the 30s, with areas in the north and nearer to any remaining snow will have a hard time reaching the freezing mark. But Sunday night the high pressure ridge axis will drift to the east and southerly flow will kick back in, ushering warmer air into the region and starting to slowly erode any remaining snow. Southwesterly flow aloft assists the warm up with the next system digging into the desert SW and amplifying the pattern across the CONUS. Big question for the first part of the week will be how much of the snow remains in the northern tier of the state. For now, temperatures start on a warming trend that will continue through the holiday. By Wednesday and Thursday, temps are above freezing through the overnight as well and the next system lays out a boundary across the region, providing a focus for plenty of rain in the Midwest in time for holiday travel. So far the models are keeping rain prolonged through Thanksgiving and into Friday. Cold air will move in again behind the system, with chilly temperatures back for next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 525 PM CST FRI NOV 20 2015 Timing of precip into the forecast area and initial affects on cigs the main challenge this evening, and then precip type and changeover late tonight as a storm system shifts south of the area. Rain has started over far western Il and expect this light rain to gradually work its way east this evening. However, forecast soundings continue to show a very dry atmosphere in place in the low levels so that will initially retard the eastward push to the rain actually reaching the ground but will include at least a VCSH across our west early this evening with the main threat for rain and snow coming in later this evening up in PIA and after midnight in BMI. RUC forecast soundings continue to suggest the changeover to snow in PIA around the midnight hour and between 08-10z at BMI with areas further south seeing mostly rain until Saturday morning. With the strongest lift moving across our area tomorrow morning there looks to be a period of IFR cigs and vsbys in snow across the north, with a changeover to light snow further south as our easterly winds tonight range from 10 to 15 kts with occasional gusts around 20 kts, shift into the north and northwest at 15 to 25 kts with a few gusts approaching 30 kts into the afternoon hours. && .ILX Watches/Warnings/Advisories... Winter Weather Advisory until noon CST Saturday for ILZ027>031- 036>038. && UPDATE...Smith SHORT TERM...Barnes LONG TERM...HJS AVIATION...Smith
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LINCOLN IL 321 PM CST FRI NOV 20 2015 ILZ027>031-036>038-211200- FULTON-KNOX-MARSHALL-MCLEAN-PEORIA-STARK-TAZEWELL-WOODFORD- 321 PM CST FRI NOV 20 2015 ...WINTER WEATHER ADVISORY IN EFFECT FROM 9 PM THIS EVENING TO NOON CST SATURDAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS...NORTH CENTRAL ILLINOIS AND WEST CENTRAL ILLINOIS. .DAY ONE...TONIGHT A MIX OF RAIN AND SNOW WILL DEVELOP ACROSS THE AREA THIS EVENING, THEN WILL TRANSITION TO ALL SNOW OVERNIGHT. MOTORISTS ARE ADVISED TO DRIVE WITH CAUTION...AS ROADS MAY BECOME SLUSHY AND SLICK LATE TONIGHT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SNOW WILL TAPER OFF BY MIDDAY SATURDAY...WITH TOTAL SNOW ACCUMULATIONS OF 1 TO 3 INCHES ALONG A CANTON TO BLOOMINGTON LINE...3 TO 4 INCHES IN THE PEORIA AREA...AND 5 TO 6 INCHES ALONG AND NORTH OF A GALESBURG TO LACON LINE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT. ILZ040>055-211200- CASS-CHAMPAIGN-CHRISTIAN-DE WITT-DOUGLAS-LOGAN-MACON-MASON-MENARD- MORGAN-MOULTRIE-PIATT-SANGAMON-SCHUYLER-SCOTT-VERMILION- 321 PM CST FRI NOV 20 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS...EAST CENTRAL ILLINOIS AND WEST CENTRAL ILLINOIS. .DAY ONE...TONIGHT LIGHT RAIN WILL DEVELOP ACROSS THE AREA THIS EVENING, THEN WILL TRANSITION TO A RAIN AND SNOW MIX OVERNIGHT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY A MIX OF RAIN AND SNOW WILL TAPER OFF AND COME TO AN END BY EARLY SATURDAY AFTERNOON. LITTLE OR NO SNOW ACCUMULATION IS EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT. ILZ056-057-061>063-066>068-071>073-211200- CLARK-CLAY-COLES-CRAWFORD-CUMBERLAND-EDGAR-EFFINGHAM-JASPER- LAWRENCE-RICHLAND-SHELBY- 321 PM CST FRI NOV 20 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL ILLINOIS...EAST CENTRAL ILLINOIS...SOUTH CENTRAL ILLINOIS AND SOUTHEAST ILLINOIS. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY MINOR FLOODING ALONG THE LITTLE WABASH RIVER NEAR CLAY CITY WILL CONTINUE THROUGH SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT. BARNES
The national radar mosaic for the moment the first event began.
3 winter storm. Local standard time, as filed.
Numerous weather observers reported 6 to 10 inches of snow across the northern half of Knox County, including 10.0 in Altona, 7.8 in Knoxville, and 7.5 1 mile north of Abingdon. The early season heavy snow caused numerous traffic accidents due to snow-covered and hazardous roadways.
Numerous weather observers reported 6 to 8 inches of snow across Marshall County, including 6.8 in Hopewell and 6.4 6 miles west of Sparland. The early season heavy snow caused numerous traffic accidents due to snow-covered and hazardous roadways.
Numerous weather observers reported 8 to 9 inches of snow across Stark County, including 8.6 in Bradford. The early season heavy snow caused numerous traffic accidents due to snow-covered and hazardous roadways.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2015Every state in 2015This day in weather historyWarnings in Illinois, November 2015
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 608377, 608378, 608379.