A weak trough of low pressure triggered a few clusters of thunderstorms across central and southeast Illinois during the afternoon and evening of August 4th. 44 of rain in a short amount of time at the Lawrenceville Airport and caused flash flooding along Illinois Route 1 on the north side of Lawrenceville.
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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 ILX wrote it up.
A weak trough of low pressure triggered a few clusters of thunderstorms across central and southeast Illinois during the afternoon and evening of August 4th. One of the most prominent clusters dropped 2.44 of rain in a short amount of time at the Lawrenceville Airport and caused flash flooding along Illinois Route 1 on the north side of Lawrenceville.
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 Lincoln, IL wrote its last area forecast discussion before the first event at Aug 4, 4:56 PM CST, 4 minutes earlier. Its key messages:
Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 556 PM CDT Mon Aug 4 2025 .KEY MESSAGES... - There is a (20-40%) chance for showers and thunderstorms this afternoon and early evening as scattered storms affect the area. Severe weather is not anticipated, but there could be a few innocuous funnel clouds and isolated heavy rainfall amounts. - Another round of scattered showers and thunderstorms is expected Tuesday afternoon and evening, with 20 to 30 percent coverage of rainfall. - A warming trend will push afternoon temperatures into the upper 80s by the end of the week. && .DISCUSSION... Issued at 223 PM CDT Mon Aug 4 2025 Scattered showers continue to develop this afternoon as expected with the return of seasonably moist humidity and dewpoints of 65 to 70 observed this afternoon as a weak, broad trough and departing high pressure have allowed a southeasterly flow to develop. With 500-100 J/kg MLCAPE developing during afternoon heating and weak shear, storms are fairly weak but slow moving, with potential for local 1-2 inch accumulations, although generally much less, with many areas remaining dry. These showers should fade away shortly after sunset, with tonight being mainly dry. Enough easterly wind, around 5 mph, and some lingering low and mid level cloud cover should be enough to keep any significant coverage of fog from developing overnight. Tuesday could be a near repeat of diurnally modulated shower/thunderstorm activity with little change in the air mass and remnants of the weak upper trough remaining. High res models indicate perhaps just slightly less coverage, so have PoPs Tuesday afternoon ranging from 20 percent in western to 30 percent in eastern IL. A high pressure ridge building out of the southwest and southern Plains will begin to dominate the weather pattern starting Wednesday, for dry conditions likely Wednesday through Saturday. A stronger trough looks to suppress the ridge late in the weekend, bringing chances for rain Saturday night into Monday. Temperatures will feature a warming trend into the weekend, with highs from lower 80s Tuesday, to upper 80s to around 90 Friday and Saturday. With the troughing and northwesterly flow nudging into the region Sunday into next week, as well as potential for rain, temperatures are likely to nudge down a few degrees. 37 && .AVIATION... (For the 00z TAFs through 00z Tuesday Evening) Issued at 556 PM CDT Mon Aug 4 2025 Isolated SHRA/-TSRA will diminish across central IL early this evening. VFR for most sites overnight, however short range guidance develops low clouds over southern IL, shifting north towards the central IL terminals late. For now have TEMPO'd in MVFR ceilings at KSPI/KDEC from 09-13z and will monitor trends this evening for coverage and category. Otherwise a few SHRA/-TSRA will again be around Tuesday afternoon. Coverage looks to be lower than today so kept mention out of TAFs. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... None. &&
Hazardous Weather Outlook National Weather Service Lincoln IL 207 PM CDT Mon Aug 4 2025 ILZ027>031-036>038-040>057-061>063-066>068-071>073-051100- Knox-Stark-Peoria-Marshall-Woodford-Fulton-Tazewell-McLean-Schuyler- Mason-Logan-De Witt-Piatt-Champaign-Vermilion-Cass-Menard-Scott- Morgan-Sangamon-Christian-Macon-Moultrie-Douglas-Coles-Edgar-Shelby- Cumberland-Clark-Effingham-Jasper-Crawford-Clay-Richland-Lawrence- 207 PM CDT Mon Aug 4 2025 This Hazardous Weather Outlook is for central Illinois, east central Illinois, southeast Illinois and west central Illinois. .DAY ONE...This Afternoon and Tonight. Isolated to scattered thunderstorms are possible through mid evening, especially from I-55 southeast. The severe threat is low, but locally heavy rain cannot be ruled out especially from I-70 southeast. Cloud to ground lightning strikes are also risks. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Isolated to scattered thunderstorms are possible Tuesday afternoon and early evening. Localized downpours and cloud to ground lightning will be the main threats. A chance of thunderstorms returns to the IL river valley overnight Saturday night, and across central and southeast IL on Sunday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated tonight. 07
The Evansville,IN radar (KVWX), 56 km away, was scanning. The volume nearest the first event began at 22:59 UTC.
1 flash flood. Local standard time, as filed.
Water was reported up to 3 feet deep along Illinois Route 1 on the north side of Lawrenceville.
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: 1289039.