A shortwave trough and closed low reached the Quad State from the northwest during the morning of the 4th. The arrival of the shortwave preceded peak heating by several hours, limiting convective potential.
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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 PAH wrote it up.
A shortwave trough and closed low reached the Quad State from the northwest during the morning of the 4th. The arrival of the shortwave preceded peak heating by several hours, limiting convective potential. Shear was very weak and instability limited. Slow-moving storms did produce torrential rainfall, with flooding issues reported in Hamilton County.
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 Paducah, KY wrote its last area forecast discussion before the first event at Aug 4, 12:55 PM CST, 1 hour 20 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Paducah KY 155 PM CDT Mon Aug 4 2025 .KEY MESSAGES... - Daily shower and thunderstorm chances will continue through Tuesday before trending drier during the latter half of the week. More rain chances return over the weekend. - Temperatures will trend warmer to near normal by Wednesday along with an increase in humidity levels. Heat Index values are forecast to remain below 100 into the weekend. && .DISCUSSION... Issued at 155 PM CDT Mon Aug 4 2025 A 500 mb shortwave trough over the region is proving enough lift to support scattered showers and thunderstorms this afternoon mainly east of the Mississippi. The greatest coverage is currently across southern Illinois along an instability axis of 1000 to 1500 J/kg of MLCAPE. Pcpn will pivot southeast this evening before diminishing with the loss of diurnal heating. Stronger storms are unlikely due to only 10-15 kts of sfc-6km shear. While conditions turn tranquil tonight, patchy fog will be possible across the entire FA as the crossover temperature is likely exceeded with dewpoints in the upper 60s to near 70 this afternoon. Another round of showers and thunderstorms will be possible on Tuesday, especially across southwest Indiana and the Kentucky Pennyrile as the aformentioned shortwave trough remains in the vicinity. Coverage looks to be more isolated compared to today with a 25 to 35% probability of pcpn. Conditions then trend drier through the latter half of the week as a H5 597 dam ridge builds east into Texas, causing the trough to lift more east out of the FA. The NBM does have slight PoPs returning over the weekend, but the LREF supports a higher probability in the 30-50% range of light QPF amounts. The greatest risk looks to be on Sunday due to an influx of tropical moisture. Unseasonably cool temperatures trend warmer to near normal by Wednesday with high temperatures back in the upper 80s to near 90. Low temperatures in the 60s trend upward into the lower 70s by the weekend. Despite an increase in humidity, heat index values are progged to remain mainly below 100. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1154 AM CDT Mon Aug 4 2025 Scattered showers and embedded thunderstorms will continue through this afternoon before diminishing this evening. KEVV/KOWB have the highest probability of MVFR conditions from storms. The other concern is low MVFR stratus and patchy fog Tuesday morning across the entire region, with MVFR to LIFR vsby reductions. Light northeast winds turn calm tonight. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && DISCUSSION...DW AVIATION...DW
Hazardous Weather Outlook National Weather Service Paducah KY 200 PM CDT Mon Aug 4 2025 ILZ075>078-080>094-INZ081-082-085>088-KYZ001>022-MOZ076-086-087- 100-107>112-114-051900- Jefferson-Wayne IL-Edwards-Wabash-Perry IL-Franklin-Hamilton- White-Jackson-Williamson-Saline-Gallatin-Union-Johnson-Pope- Hardin-Alexander-Pulaski-Massac-Gibson-Pike-Posey-Vanderburgh- Warrick-Spencer-Fulton-Hickman-Carlisle-Ballard-McCracken-Graves- Livingston-Marshall-Calloway-Crittenden-Lyon-Trigg-Caldwell- Union KY-Webster-Hopkins-Christian-Henderson-Daviess-McLean- Muhlenberg-Todd-Perry MO-Bollinger-Cape Girardeau-Wayne MO-Carter- Ripley-Butler-Stoddard-Scott-Mississippi-New Madrid- 200 PM CDT Mon Aug 4 2025 /300 PM EDT Mon Aug 4 2025/ This Hazardous Weather Outlook is for portions of southern Illinois, southwest Indiana, western Kentucky, and southeast Missouri. .DAY ONE...This Afternoon and Tonight Isolated thunderstorms are possible this afternoon, mainly east of the Mississippi River. Cloud to ground lightning and locally heavy rain is the primary hazard. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Additional showers and thunderstorms are possible on Tuesday with the greatest chances east of the Mississippi River. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. DW
The Evansville,IN radar (KVWX), 78 km away, was scanning. The volume nearest the first event began at 20:15 UTC.
1 flash flood, 1 flood. Local standard time, as filed.
A vehicle was stuck in water on IL-14 at Ten Mile Rd around the time rainfall rates peaked at around 0.75'' in 15 minutes.
Floodwaters resulted in the closure of part of IL-142 near County Rd 975N. One hour rainfall rates peaked at around 2'' (radar estimated) in that area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2025Every state in 2025This day in weather historyWarnings in Illinois, August 2025
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: 1289942, 1289943.