After midnight on March 18, an upper level low moving into northeast Illinois helped produce severe thunderstorms with up to one inch diameter hail in Mc Donough and Warren Counties. Early morning low temperatures ranged from 51 degrees at Maquoketa to 61 degrees at Independence, Muscatine, and Vinton.
Every event with a place to put it. 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.
After midnight on March 18, an upper level low moving into northeast Illinois helped produce severe thunderstorms with up to one inch diameter hail in Mc Donough and Warren Counties. Early morning low temperatures ranged from 51 degrees at Maquoketa to 61 degrees at Independence, Muscatine, and Vinton.
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 Mar 17, 11:26 PM CST, 17 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1226 AM CDT SUN MAR 18 2012 .AVIATION... VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. LOW CLOUDS THAT WERE ANTICIPATED TO DEVELOP AND SPREAD ACROSS EASTERN IOWA BY EARLY THIS MORNING HAVE NOT YET MATERIALIZED. THEREFORE HAVE REMOVED THE MVFR CEILINGS AND WENT WITH VFR CLOUDS DURING THE MORNING. MORE VFR CUMULUS CLOUD DEVELOPMENT IS EXPECTED DURING THE DAYTIME HEATING HOURS SUNDAY. SOME OF THE MODELS HAVE INDICATED THERE COULD BE SOME PATCHY FOG DEVELOPMENT THIS MORNING...BUT HAVE KEPT ANY FOG OUT OF THE FORECAST FOR NOW AS WINDS MAY REMAIN STRONG ENOUGH. SOUTHERLY WINDS WILL CONTINUE THROUGHOUT THE DAY SUNDAY...WITH WINDS INCREASING TO AROUND 15KTS WITH GUSTS OF 20-25KTS DURING THE AFTERNOON. ..STOFLET.. && .PREV DISCUSSION... /ISSUED 305 PM CDT SAT MAR 17 2012/ SYNOPSIS... RECORD WARMTH MORE TYPICAL OF LATE MAY INTO EARLY JUNE CONTINUES. SURFACE ANALYSIS DEPICTS WEAK DISTURBANCE IN MISSOURI TO PASS TO OUR SOUTH NEXT 6 HOURS. SOUTH FLOW TO CONTINUE WITH LITTLE FORCING TO IMPACT AREA NEXT 36 PLUS HOURS. DIGGING TROUGH JUST ARRIVING IN THE PACIFIC COAST THAT SHOULD BE ONSHORE SUNDAY MORNING FOR BETTER SAMPLING. TRENDS SUGGEST A CONTINUED SOUTH SHIFT OF THIS SYSTEM NEXT 5 DAYS KEEPING STRONGER STORMS AND HEAVIEST RAINS SOUTH OF THE AREA. NEAR TERM TOOLS SUPPORT MORE RECORD WARMTH AT LEAST NEXT 24 HOURS AND LIKELY FOR ANOTHER 48 HOURS BEFORE CLOUDS AND COOLER TEMPERATURES ARRIVE. SHORT TERM...TONIGHT AND SUNDAY... TONIGHT...PERSISTENCE AGAIN KEY FOR MINS TONIGHT WITH AREAS OF LOW CLOUDS TO MOVE AND/OR DEVELOP AFTER MIDNIGHT. THIS SHOULD KEEP MINS IN THE 58-63 DEGREE RANGE WITH SOUTH WINDS OF 5-10 MPH. THIS WOULD AGAIN SHATTER WARM LOW RECORDS BY 8 TO 12 DEGREES. ISOLATED STORMS POSSIBLE THIS EVENING BUT TRENDS SUGGEST THIS RISK WILL END BY MID TO LATE EVENING AS MISSOURI SYSTEM SLIDES EAST. MAY BE ABLE TO REMOVE POPS NEXT 3 TO 4 HOURS IF THIS TREND CONTINUES. SUNDAY...ALMOST A CARBON COPY OF SATURDAY WITH HIGHS 78-83F SUGGESTED AND SOUTH WINDS INCREASING TO 15 TO 25 MPH IN THE AFTERNOON. LOW CLOUDS SHOULD DISPERSE BY MID TO LATE MORNING ENSURING ANOTHER RECORD BREAKING WARM DAY. GRASSLAND FIRE DANGER INDEX MAY APPROACH VERY HIGH LEVELS FOR A FEW HOURS IN THE EARLY AFTERNOON BUT RH VALUES OF 50+ PERCENT OR HIGHER ALONG WITH MODERATE WINDS ARE NOT FAVORABLE FOR WIDESPREAD FIRE DANGER ATTM. ..NICHOLS.. LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY... QUIET CONDITIONS WILL BE SEEN SUNDAY EVENING AS THERE IS NO FORCING MECHANISM TO GET PRECIP GOING. AFTER MIDNIGHT...A LLJ IS ACROSS THE AREA WITH THE STRONGEST WINDS JUST WEST OF THE CWFA. MCS AND LIFT TOOLS SUGGEST CONVECTION SHOULD DEVELOP WEST/SOUTHWEST OF THE CWFA SUNDAY EVENING WITH A VORT MAX. THAT CONVECTION SHOULD PROPAGATE INTO THE WESTERN HALF OF THE CWFA AFTER MIDNIGHT. THUS WILL GO WITH SCHC/CHC POPS WEST OF THE MISSISSIPPI WITH THE BETTER CHC ACROSS THE WESTERN THIRD OF THE CWFA. NOCTURNAL CONVECTION SHOULD LINGER OVER ROUGHLY THE WESTERN HALF OF THE CWFA DURING THE FIRST PART OF THE MORNING. DIFFERENTIAL HEATING MAY ALLOW NEW CONVECTION TO DEVELOP PRIOR TO MID DAY OVER THE REMAINDER OF THE CWFA. CONVECTION SHOULD BECOME MORE NUMEROUS MONDAY AFTERNOON ONCE CONVECTIVE TEMPERATURE IS REACHED. MONDAY NIGHT/TUESDAY A STRONG LLJ AND MOISTURE FEED IS SET UP ACROSS THE CWFA ON THE WARM SIDE OF THE APPROACHING SYSTEM. MCS AND LIFT TOOLS SUGGEST THE BEST CHANCES FOR RAIN WILL BE ACROSS THE WESTERN THIRD TO HALF OF THE CWFA. SINCE THE MODELS PROG THE MAIN ENERGY OF THE SYSTEM TO PASS SOUTH OF THE AREA...THE STRONGER CONVECTION AND THUS HEAVIER RAIN WILL BE SOUTH OF THE CWFA. TUESDAY NIGHT ON... MODEL CONSENSUS GIVES CHC TO LIKELY POPS FOR TUES NIGHT/WED WHICH WILL PROBABLY NEED TO BE RAISED WITH TIME. DPROG/DT OF THE MODELS CONTINUE TO SHOW THE MAIN ENERGY BEING A BIT FURTHER SOUTH/EAST AND THIS TREND WILL LIKELY CONTINUE UNTIL THE ENERGY COMES ON SHORE AND IS FULLY SAMPLED BY THE UA NETWORK. IF THIS FURTHER SOUTH/EAST TREND CONTINUES THEN WEDNESDAY WILL PROBABLY BE THE LAST DAY FOR ANY TSRA. WED NIGHT/THURS THE CONSENSUS GIVE CHC POPS WHICH LOOKS REASONABLE ATTM. THE PASSAGE OF THE MAIN ENERGY SOUTH OF THE AREA CONCEPTUALLY WILL PUT THE AREA IN THE COLD CONVEYOR BELT AND A HIGHER PROBABILITY OF THE PRECIPITATION BEING MORE STRATIFORM THAN CONVECTIVE. LINGERING PRECIP WITH SCHC TO LOW CHC POPS SHOULD BE SEEN THURS NIGHT/FRIDAY. HOWEVER...THE POPS FOR FRIDAY WILL BE DEPENDENT UPON HOW FAST THE UPPER LOW MOVES EAST OF THE AREA. THE POSSIBILITY DOES EXIST THAT FRIDAY COULD BE DRY. FRIDAY NIGHT THROUGH SATURDAY NIGHT GENERALLY DRY CONDITIONS SHOULD BE SEEN ACROSS THE AREA. TEMPERATURES WILL CONTINUE TO BE WELL ABOVE NORMAL BUT WILL BE CLOSER TO NORMAL BY NEXT WEEKEND. ..08.. && .CLIMATE... RECORD HIGHS FOR MARCH 18TH BURLINGTON........80 IN 1918 CEDAR RAPIDS......79 IN 1918 DUBUQUE...........77 IN 1918 MOLINE............76 IN 1918 RECORD HIGHS FOR MARCH 19TH BURLINGTON........79 IN 1921 CEDAR RAPIDS......80 IN 1921 DUBUQUE...........77 IN 1921 MOLINE............78 IN 1921+ RECORD HIGHS FOR MARCH 20TH BURLINGTON........78 IN 1921 CEDAR RAPIDS......76 IN 1938 DUBUQUE...........77 IN 1921 MOLINE............77 IN 1921 RECORD WARM LOW TEMPERATURES FOR MARCH 18TH... MOLINE.........52 IN 1894 DUBUQUE........49 IN 1894 RECORD WARM LOW TEMPERATURES FOR MARCH 19TH... MOLINE.........63 IN 1921 DUBUQUE........49 IN 1910 RECORD WARM LOW TEMPERATURES FOR MARCH 20TH... MOLINE.........48 IN 1918 DUBUQUE........42 IN 1910 RECORD WARM LOW TEMPERATURES FOR MARCH 21ST... MOLINE.........54 IN 1894 DUBUQUE........52 IN 1938 RECORD WARM LOW TEMPERATURES FOR MARCH 22ND... MOLINE.........56 IN 1907 DUBUQUE........49 IN 1907 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && WDN/08/STOFLET
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE QUAD CITIES IA IL 500 AM CDT SAT MAR 17 2012 IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007- 009-015>018-024>026-034-035-MOZ009-010-181000- BENTON IA-BUCHANAN IA-BUREAU IL-CARROLL IL-CEDAR IA-CLARK MO- CLINTON IA-DELAWARE IA-DES MOINES IA-DUBUQUE IA-HANCOCK IL- HENDERSON IL-HENRY IA-HENRY IL-IOWA IA-JACKSON IA-JEFFERSON IA- JO DAVIESS IL-JOHNSON IA-JONES IA-KEOKUK IA-LEE IA-LINN IA-LOUISA IA- MCDONOUGH IL-MERCER IL-MUSCATINE IA-PUTNAM IL-ROCK ISLAND IL- SCOTLAND MO-SCOTT IA-STEPHENSON IL-VAN BUREN IA-WARREN IL- WASHINGTON IA-WHITESIDE IL- 500 AM CDT SAT MAR 17 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...TODAY AND TONIGHT THERE IS A CHANCE FOR AN ISOLATED THUNDERSTORM IN NORTHWESTERN ILLINOIS THROUGH 730 AM CDT THIS MORNING. OTHERWISE...ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON MAINLY ALONG AND SOUTH OF INTERSTATE 80. THEN THERE WILL BE A CHANCE FOR A FEW MORE STORMS TONIGHT ALONG AND EAST OF THE MISSISSIPPI RIVER. SEVERE STORMS ARE NOT EXPECTED TODAY OR TONIGHT...BUT A STRONGER STORM MAY BE ABLE TO PRODUCE HAIL UP TO A HALF INCH IN DIAMETER AND LOCALLY HEAVY DOWNPOURS. WARM TEMPERATURES...BRISK WINDS...AND DRIED VEGETATION WILL COMBINE TO RESULT IN A VERY HIGH THREAT OF GRASS FIRES TODAY. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A SLOW MOVING UPPER LEVEL SYSTEM COMBINED WITH WARM TEMPERATURES AND A MOIST ATMOSPHERE WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS MONDAY THROUGH THURSDAY. IT IS TOO EARLY TO DETERMINE THE THREAT FOR ANY SEVERE STORMS. THERE ARE SOME INDICATIONS OF HEAVY RAINFALL ON MONDAY AND TUESDAY...WITH RAINFALL AMOUNTS OF 1 TO 2 INCHES POSSIBLE MONDAY THROUGH TUESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT. 12/LE
The Lincoln radar (KILX), 118 km away, was scanning. The volume nearest the first event began at 05:41 UTC.
6 hail. Local standard time, as filed.
At 1243 am CDT March 18, half dollar sized hail fell 2 miles south southeast of Macomb, IL.
At 1243 am CDT March 18, ping pong ball sized hail fell 1 mile south of Macomb, IL.
At 1244 am CDT March 18, quarter sized hail fell 1 mile south of Macomb, IL.
At 1244 am CDT March 18, quarter to half dollar sized hail fell in Macomb, IL.
At 1245 am CDT March 18, quarter sized hail fell 1 mile southeast of Macomb, IL.
At 130 am CDT March 18, quarter to half dollar sized hail fell 1 mile west of Greenbush, IL. This report was relayed by the Lincoln, IL NWS office.
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, March 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: 373010, 373012, 373018, 373020, 373022, 373026.