On the afternoon of July 3, an upper-level system moving northeastward from the St. Louis, MO area, across Illinois, into southern Wisconsin.
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 LOT wrote it up.
On the afternoon of July 3, an upper-level system moving northeastward from the St. Louis, MO area, across Illinois, into southern Wisconsin. This system produced several bands of showers and thunderstorms, which moved northeastward across the region. One band moved through the Chicago metro area and southern Lake Michigan, producing isolated large hail and strong wind gusts.
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 Jul 3, 2:25 PM CST, 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 325 PM CDT SAT JUL 3 2004 .DISCUSSION... ...UPDATE 325 PM...WILL BE DROPPING TOR WATCH FOR ALL WFO LOT COUNTIES WITH ZFP ISSUANCE. HAVE ISSUED URBAN/SMALL STRM ADVISORY FOR NERN IL AND LAKE/PORTER IND. FOCUS OF FORECAST ON SHORTER TERM WITH UPPER SYSTEM AND HOLIDAY FESTIVITIES THROUGH MONDAY. CLOSED UPPER LOW HIGHLY EVIDENT IN GOES VAPOR IMAGERY OVER XTRM NERN MO THIS AFTN...WITH VORT MAX NOTED MOVING OUT OF BASE OF TROUGH AND LIFTING NORTHEAST INTO CNTRL IL. WIDESPREAD INCRS IN DIUNAL CONVECTION OCCURRING AS IS TYPICAL WITH THESE FEATURES IN WARM SEASON. NWP CONSISTENT IN MOVG UPPER CIRCULATION NORTHEAST ACROSS NRN IL TONIGHT...WITH ETA PREFERRED IN SLIGHTLY SLOWER PROGRESS TYPICAL OF CLOSED UPPER SYSTEMS. THUS WILL CONTINUE CATEGORICAL POPS THROUGH EVENING THEN TAPER TO CHANCE POPS ACROSS SOUTHWESTERN CWA AFTER MIDNIGHT AS TROUGH AXIS MOVES NORTHEAST AND DIURNAL LULL IN CONVECTION DEVELOPS. WITH SLOWER SOLUTION OF ETA PREFERRED HAVE KEPT LOW CHC POPS INTO SUNDAY MORNING AS UPPER TROUGH SLOWLY PULLS OUT. HAVE ELECTED TO KEEP LOW CHC POPS CWA WIDE INTO AFTN AS WELL...AS ALL GUIDANCE BRINGING SECONDARY S/WV INTO MID/UPPER MS VLY BY AFTN. THIS APPEARS TO HAVE CONTINUITY WITH S/WV CURRENTLY EVIDENT IN VAPOR IMAGERY OVER WY...THOUGH GFS APPEARS TO OVERDO STRENGTH OF THIS FEATURE THRU 24-36 HOURS AS RESULT OF CONVECTIVE FEEDBACK. ETA/META INDICATE LLVL MOISTURE REMAINING IN PLACE ACROSS FCST AREA SUN AFTN WITH SFC DEWPOINTS IN UPPER 60S. META FCST SOUNDINGS SHOWING MODERATE INSTALBILITY DVLPG SBCAPE OF 2000 J/KG BY AFTN ESPECIALLY SRN CWA...WITH UNIDIRECTIONAL WESTERLY SHEAR PROFILES. SPC HAS INCLUDED SERN HALF OF CWA IN DAY 2 SLGT RISK. APPEARS FCST AREA TO DRY OUT SUN NGT AS COLD FRONT SLIPS IN FROM THE NORTH AND WEAK S/WV RIDGING DVLPS BY MONDAY MORNING. FRONT SAGS INTO/JUST SOUTH OF FCST AREA MON MORNING...BEFORE NEXT S/WV MOVES ACROSS CNTRL PLAINS AND LIFTS FRONT BACK NORTH LATE MON AND MON NGT. NXT CHC POPS IN PLACE WITH NORTHWARD MOVEMENT OF THE FRONT FAR SOUTHWEST SECTIONS MON AFTN AND ENTIRE CWA MON NGT. TEMP WISE...HAVE RAISED MIN TEMPS A BIT TNGT WITH DEWPOINTS HANGING IN UPPER 60S. OTHER SIG CHANGE WAS TO ACCOUNT FOR COOLER MAXES ON MON N/NERN COUNTIES WITH NE FLOW OF LAKE MICH. RATZER && .AVIATION... FOR 18Z TAFS...CURRENT EXPANSION OF TSRA WILL MOVE INTO THE TERMINALS LATER THIS AFTERNOON. MFVR TO IFR CIGS/VIS IS ANTICIPATED ASSOCIATED WITH THE STRONGEST CELLS. TSRA WILL TRANSITION OVER TO SHRA BY 00Z AND PERSIST UNTIL NEAR 06Z. OVC CIGS ANTICPATED TO LOWER AFTER THE PRECIP ENDS TO NEAR 1000 FT AGL OVERNIGHT GIVEN HIGH MOISTURE FIELDS. SHORTLY AFTER SUNRISE CIGS SHOULD BECOME BKN AOA 3000 FT AGL. SFC WINDS TONIGHT WILL PERSIST OUT OF TEH SE THEN VEER AFTER MINIGHT TO THE SW...WESTERLY FLOW TOMORROW. && .LOT...WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LK MI...NONE.
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE CHICAGO IL 300 PM CDT SAT JUL 3 2004 ILZ003>006-008-010>014-019>022-023-032-033-039-INZ001-002-010-011-019 -041100- 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- 300 PM CDT SAT JUL 3 2004 THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND NORTHEAST ILLINOIS...AND NORTHWEST INDIANA. .DAY ONE...THIS AFTERNOON AND TONIGHT RAIN SHOWERS AND OCCASIONAL THUNDERSTORMS WILL BECOME NUMEROUS ACROSS THE REGION THIS AFTERNOON AND INTO TONIGHT. THE MAIN CONCERN FROM THE ACTIVITY WILL BE LOCALLY BRIEF HEAVY RAIN ASSOCIATED WITH THE STRONGER STORMS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE MORNING ON SUNDAY. THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE LATE MONDAY NIGHT THROUGH EARLY WEDNESDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WWW.CRH.NOAA.GOV/LOT (LOWER CASE) LMZ740>746-766-041100- WINTHROP HARBOR IL TO NEW BUFFALO MI- LAKE MICHIGAN- 300 PM CDT SAT JUL 3 2004 THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS AND INDIANA WATERS OF LAKE MICHIGAN. .DAY ONE...THIS AFTERNOON AND TONIGHT RAIN SHOWERS AND OCCASIONAL THUNDERSTORMS ARE EXPECTED THROUGH TONIGHT. SOME OF THE SHOWERS AND THUNDERSTORMS MAY PRODUCE PERIODS OF HEAVY RAIN. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE MORNING ON SUNDAY. THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE LATE MONDAY NIGHT THROUGH EARLY WEDNESDAY MORNING. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WWW.CRH.NOAA.GOV/LOT (LOWER CASE) 05
ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039-INZ010-INZ011-INZ019- 040000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHICAGO IL 324 PM CDT SAT JUL 3 2004 ILZ019-021-023-032-033-039-INZ010-011-019-040000- THE NATIONAL WEATHER SERVICE IN CHICAGO HAS CLEARED ALL COUNTIES IN TORNADO WATCH 540. COUNTIES CLEARED INCLUDE: IN ILLINOIS: FORD...GRUNDY...IROQUOIS...KANKAKEE...LA SALLE...LIVINGSTON... IN INDIANA: BENTON...JASPER...NEWTON... THIS INCLUDES THE CITIES OF...FOWLER...GIBSON CITY...KANKAKEE... LA SALLE...MOROCCO...MORRIS...PONTIAC...RENSSELAER...WATSEKA... AEP
The Chicago radar (KLOT), 71 km away, was scanning. The volume nearest the first event began at 20:47 UTC.
2 thunderstorm wind. Local standard time, as filed.
Power lines were torn down. Large tree limbs and moderate sized trees were broken off and on top of houses.
Power lines and large tree branches were down across the city.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Indiana in 2004Every state in 2004This day in weather historyWarnings in Indiana, July 2004
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: 5412816, 5412817.