A strong storm system moved from the Southern Plains into northern Ohio from Thursday February 23rd into Friday February 24th. Precipitation started falling as rain during the late morning on the 23rd across northwest Illinois and began mixing with snow in the early afternoon before finally changing over to snow from west to east by mid afternoon and by late evening to the south.
Every event with a place to put it; 7 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 DVN wrote it up.
A strong storm system moved from the Southern Plains into northern Ohio from Thursday February 23rd into Friday February 24th. Precipitation started falling as rain during the late morning on the 23rd across northwest Illinois and began mixing with snow in the early afternoon before finally changing over to snow from west to east by mid afternoon and by late evening to the south. Snow continued, heavy at times overnight Thursday into Friday morning before exiting to the east. Snowfall totals ranged from one to two inches south of Interstate 80 to 6 or more inches north of Highway 30.
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 Quad Cities, IA wrote its last area forecast discussion before the first event at Feb 23, 10:26 AM CST, 2 hours 34 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1026 AM CST THU FEB 23 2012 .UPDATE... PRECIPITATION MOSTLY IN THE FORM OF RAIN HAS SPREAD NORTHWARD TO THE I-80 CORRIDOR AT MID MORNING. TEMPERATURES CONTINUE TO SLOWLY RISE BEFORE THE PRECIPITATION ARRIVES AS THE BOUNDARY LAYER WARMS JUST ENOUGH. HOWEVER JUST ABOVE THE BOUNDARY LAYER TEMPERATURES ARE BELOW FREEZING FROM I-80 NORTHWARD AND REMAINS THAT WAY ALL DAY. WE COULD BE ALTERNATING BETWEEN RAIN AND SNOW IN OUR NORTH DEPENDING ON THE INTENSITY OF THE PRECIPITATION. AS THE SURFACE LOW IN MO ORGANIZES AND MOVES INTO NORTHERN OHIO LATER TONIGHT A DEFORMATION BAND OF PRECIPITATION...MOSTLY AS SNOW... DEVELOPS ACROSS THE DVN CWA. ONCE SUNSET ARRIVES THE BOUNDARY LAYER SHOULD COOL JUST ENOUGH TO TURN EVERYTHING OVER TO ALL SNOW WHICH WILL LAST THROUGH THE NIGHT. POTENTIAL FOR 2 TO 5 INCHES OF ACCUMULATION TONIGHT ESPECIALLY FROM ABOUT I-80 NORTHWARD SO HEADLINES FOR AN ADVISORY MAY BE NEEDED TO BE ISSUED THIS AFTERNOON. WILL CONTINUE TO MONITOR. ..HAASE.. && .AVIATION... /ISSUED 606 AM CST THU FEB 23 2012/ VFR CONDITIONS TO DETERIORATE TO IFR CONDITIONS ALL TERMINALS BETWEEN 12-16Z. PERIODS OF LIGHT RAIN TO OVERSPREAD ALL TERMINALS BY 17Z WITH MOSTLY IFR CONDITIONS AND LOW MVFR POSSIBLE. AFTER 20Z...RAIN TO MIX WITH AND CHANGE TO SNOW BETWEEN 20-23Z AT CID/DBQ AND 00-03Z AT MLI/BRL. IFR SOME LIFR CONDITIONS WITH LIGHT SNOW TO PERSIST UNTIL 09Z WITH SNOW ENDING CIRCA 09-12Z WITH MOSTLY MVFR CONDITIONS. ..NICHOLS.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && HAASE
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1201 PM CST THU FEB 23 2012 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-241815- BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON- CEDAR-CLINTON-MUSCATINE-SCOTT-KEOKUK-WASHINGTON-LOUISA-JEFFERSON- HENRY IA-DES MOINES-VAN BUREN-LEE-JO DAVIESS-STEPHENSON-CARROLL- WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM-MERCER-HENDERSON- WARREN-HANCOCK-MCDONOUGH-SCOTLAND-CLARK- 1201 PM CST THU FEB 23 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL ILLINOIS...NORTHWEST ILLINOIS...WEST CENTRAL ILLINOIS...EAST CENTRAL IOWA...NORTHEAST IOWA...SOUTHEAST IOWA AND NORTHEAST MISSOURI. .DAY ONE...THIS AFTERNOON AND TONIGHT WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO 6 AM FRIDAY FOR AREAS FROM NEAR INTERSTATE 80 NORTH TO HIGHWAY 20. RAIN OR RAIN MIXED WITH SNOW THIS AFTERNOON WILL CHANGE TO LIGHT TO MODERATE WET SNOW THIS EVENING FROM INTERSTATE 80 NORTHWARD TO HIGHWAY 20. ACCUMULATIONS OF 2 TO 5 INCHES CAN BE EXPECTED TONIGHT. LOCATIONS SOUTH OF I-80 WILL HAVE RAIN THIS EVENING GRADUALLY CHANGING TO LIGHT SNOW AFTER MIDNIGHT WITH ACCUMULATIONS LESS THAN 2 INCHES. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY A STRONG STORM SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST LATE SUNDAY INTO MONDAY. THERE MAY BE A BRIEF PERIOD OF RAIN OR SNOW IN PORTIONS OF THE OUTLOOK AREA SUNDAY NIGHT BUT THE BULK OF THE PRECIPITATION SHOULD REMAIN OVER MINNESOTA AND WISCONSIN. THE MAIN IMPACT FROM THIS SYSTEM WILL BE STRONG GUSTY WINDS OF 30 TO 40 MPH SUNDAY AND AGAIN ON MONDAY. FURTHER OUT...THERE ARE SIGNS THAT ANOTHER POTENTIALLY STRONG STORM SYSTEM MAY BRING RAIN OR SNOW TO THE AREA FROM TUESDAY NIGHT INTO WEDNESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED THIS AFTERNOON OR TONIGHT. HOWEVER...SNOWFALL REPORTS OF ONE INCH OR MORE WOULD BE APPRECIATED TONIGHT. HAASE
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE QUAD CITIES IA IL 747 AM CST THU FEB 23 2012 IAZ042-054-066-068-ILZ001-002-007-009-015>018-231500- DUBUQUE-JACKSON-CLINTON-SCOTT-JO DAVIESS-STEPHENSON-CARROLL- WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM- INCLUDING THE CITIES OF...DUBUQUE...MAQUOKETA...CLINTON... BETTENDORF...DAVENPORT...GALENA...FREEPORT...MOUNT CARROLL... STERLING...ROCK FALLS...MOLINE...ROCK ISLAND...KEWANEE... PRINCETON...HENNEPIN 747 AM CST THU FEB 23 2012 ...AREAS OF DENSE FOG EARLY THIS MORNING ACROSS PORTIONS OF FAR EASTERN IOWA AND NORTHWEST ILLINOIS... AREAS OF DENSE FOG REDUCING VISIBILITIES DOWN TO A QUARTER MILE OR LESS...WILL CONTINUE THROUGH 9 AM CST THIS MORNING ACROSS PORTIONS OF FAR EASTERN IOWA AND NORTHWESTERN ILLINOIS. THESE LOCALIZED AREAS OF DENSE FOG WILL CONTINUE UNTIL NORTHEAST WINDS INCREASE ENOUGH TO HELP IMPROVE VISIBILITIES. IN ADDITION...MANY LOCATIONS REMAIN BELOW FREEZING...SO ANY FOG MAY RESULT IN A GLAZE FORMING ON SOME ROADS...ESPECIALLY ELEVATED SURFACES. ANYONE TRAVELING EARLY THIS MORNING SHOULD BE AWARE OF POSSIBLE SLIPPERY ROAD CONDITIONS...ESPECIALLY ON ELEVATED SURFACES SUCH AS BRIDGES AND OVERPASSES. ALSO BE AWARE OF SHARPLY REDUCED VISIBILITIES OCCURRING IN A SHORT DISTANCE. NICHOLS
The national radar mosaic for the moment the first event began.
7 winter weather. Local standard time, as filed.
The heaviest snowfall reported by trained spotters ranged from 4.5 inches 1 mile south southwest of Coleta to 4.5 inches 3 miles east of Morrison.
Trained COOP Observers reported snowfall totals that ranged from 5.5 inches of snow 3 miles southeast of Galena to 5.8 inches 1 miles west of Elizabeth.
Storm total snowfall reports from trained spotters ranged from 5.1 inches 1 mile south southeast of Shannon to 6.8 inches west northwest of Mount Carroll.
Snowfall totals reported by trained spotters ranged from 6.5 inches at 2 miles northwest of Organeville to 7.5 inches in Freeport.
Trained spotters reported total snowfall ranging from 3.1 inches 2 miles south southeast of Rock island to 4.5 inches 1 mile south southwest of Cordova.
A trained spotter reported 3.5 inches 2 miles northwest of Kewanee.
A trained spotter reported 2.2 inches of snow east of Tiskilwa.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2012Every state in 2012This day in weather historyWarnings in Illinois, February 2012
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: 368242, 368240, 368253, 368241, 368257, 368258, 368259.