1 hail, as filed by the National Weather Service.
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 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 Chicago, IL wrote its last area forecast discussion before the first event at May 18, 5:00 AM CST, 6 hours 48 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 600 AM CDT THU MAY 18 2006 .DISCUSSION FOR MORNING ZONES/GRIDS... 330 AM CDT A QUIET NIGHT AFTER THE EVENING FIREWORKS. THE STRONG SHORTWAVE THAT TRIGGERED THE CONVECTION HAS MOVED WELL EAST OF THE REGION. UNDER SUBSIDENCE FOLLOWING THE EXITING SHORTWAVE...ALLOWING SKIES TO BECM MOSTLY CLEAR. RADIATIVE COOLING AND WET GROUND HAS LED TO PATCHY FOG FORMING. EVEN THOUGH SOME WEAK UVV IS MOVING DOWN FROM WISCONSIN TOWARD THE CWA...PER SCT CU SEEN ON LATEST SATELLITE IMAGERY AND MODEL OMEGA FIELDS...BUT WEAK SUBSIDENCE IS EXPECTED FOR LATER TODAY. WITH AMBLE SUNSHINE AND RESIDUAL LOW LEVEL MOISTURE FROM THE RECENT RAIN...PERHAPS SOME ISOL INSTABILITY SHRS ARE POSSIBLE THIS AFTERNOON. CHANCES VERY LOW SO WILL KEEP OUT OF THE ZONES FOR NOW. FOR THE REMAINDER OF THE SHORT TERM FORECAST...ONLY HAVE DONE SOME MINOR TWEAKING. THE MODEL GUIDANCE HAS BEEN CONSISTENT ON HANDLING THE HIGH AMPLITUDE...SHORT WAVELENGTH PATTERN OVER THE CONUS. THE TRENDS HAVE BEEN FOR ONLY VERY SLOW PROGRESSION WITH A LITTLE DECREASE IN AMPLITUDE OVER THE NEXT FEW DAYS. NEXT CHANCE OF RAIN WILL BE SATURDAY NIGHT AS A WEAK WARM FRONT SETS UP OVER CNTRL IL/IN WITH A WEAK SHORTWAVE SLIDING ACROSS THE BNDRY. NOT A LOT OF FORCING WITH THIS SYSTEM...SO NOT EXPECTING MORE THAN SHOWERS AT THIS TIME. INTO THE LONGER TERM...NO CHANGES MADE TO THE EXTENDED PERIOD BEYOND THE WEEKEND...GIVEN THE DECENT RUN-TO-RUN MODEL CONSISTENCY. AS THE SYNOPTIC PATTERN BECOMES MORE PROGRESSIVE WITH DECREASING AMPLITUDE NEXT WEEK...EXPECTING RIDGING TO BUILD OVER THE CENTRAL PLAINS AND UPPER MIDWEST. THIS COULD LEAD TO SGFNT WARMING FOR THE LOCAL AREA WITH TEMPS REACHING INTO THE 80S FOR THE FIRST TIME THIS SPRING. HOWEVER...AS IS USUALLY THE CASE WITH THE LONGER RANGE...WILL HAVE TO SEE HOW THE SMALLER SCALE FEATURES INTERACT WITH THE LARGER SCALE...AND NOT GET TOO EXCITED JUST YET...SINCE THE PATTERN OVER THE CONUS IS SO HIGH AMPLITUDE...IT WILL TAKE SGFNT ENERGY TO BREAK DOWN THE PATTERN. KREIN && .AVIATION DISCUSSION REGARDING 12Z TAFS... HAVE MADE SOME CHGS TO NR TERM OF FCST. SATLT LOOPS SHOW AREA OF HI BASED SHWRS DVLPG/MOVG SSEWD ACROSS ERN-SRN WI. CLOUD MOTION AND ORIENTATION SUGGEST MID LVL IMPULSE IS DIGGING SSEWD ACROSS THIS AREA IN SUPPORT OF DEEPENING CLOSED LOW OVR LWR MICH ATTM. UPWARD MOTION WITH ASSD MID LVL WIND MAX PUNCHING SWD ACRS WI...AND REINFORCEMENT OF COLD AIR ALF SUGGEST THIS RGN OF MID LVL INSTABILITY WILL BE MOVG ACRS TERMINAL AREA THIS MRNG BRINGING A PERIOD OF LGT SHWRS. NOT A LOT OF LWRING IN VIS ASSD WITH THIS...BUT ENUF TO WET RUNWAYS FOR A TIME. THIS FEATURE TO ROTATE THROUGH RGN BY 15-16Z. IN ITS WAKE...FCST SOUNDINGS SUGGEST PROXIMITY TO COLD UPR LOW TO E WILL ALLOW FOR BKN CU DVLPMT BY AFTN DUE TO DIURNAL HEATING/MIXING. PASSAGE OF THIS DISTURBANCE LATER THIS MRNG WILL ALSO BRING INCRS IN WIND SPEED DOWN TO SFC WITH SOME GUSTS APCHG 25 KTS DURG AFTN. CONDS TO IMPROVE THIS EVENING AS WIND GUSTS DMNSH AND DIURNAL CU FIELD LIFTS AND SCATTERS OUT...EVENTUALLY GOING TO CLR SKIES AND LGT NWLY SFC FLOW BY 06Z. MERZLOCK && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 430 AM CDT THU MAY 18 2006 ILZ003>006-008-010>014-019>022-023-032-033-039-INZ001-002-010-011- 019-190930- WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DU PAGE-COOK- LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-IROQUOIS-FORD- LAKE IN-PORTER-NEWTON-JASPER-BENTON- 430 AM CDT THU MAY 18 2006 THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND NORTHEAST ILLINOIS...AND NORTHWEST INDIANA. .DAY ONE... TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN... FRIDAY THROUGH WEDNESDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NECESSARY. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO (LOWER CASE) LMZ740>745-766-190930- WINTHROP HARBOR IL TO MICHIGAN CITY IN- LAKE MICHIGAN- 430 AM CDT THU MAY 18 2006 THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS AND INDIANA WATERS OF LAKE MICHIGAN. .DAY ONE... TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN... FRIDAY THROUGH WEDNESDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO (LOWER CASE)
The Chicago radar (KLOT), 95 km away, was scanning. The volume nearest the first event began at 17:48 UTC.
1 hail. Local standard time, as filed.
Quarter size hail was reported between Onarga and Gilman on Interstate 57, near mile marker 282.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2006Every state in 2006This day in weather historyWarnings in Illinois, May 2006
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: 5510169.