A slow-moving frontal boundary triggered a couple bands of showers and thunderstorms across southeast Illinois from late morning through mid-afternoon of August 3rd. 65.
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 ILX wrote it up.
A slow-moving frontal boundary triggered a couple bands of showers and thunderstorms across southeast Illinois from late morning through mid-afternoon of August 3rd. The heaviest rainfall of 2 to 5 inches occurred from near Flora in Clay County northeastward to Robinson in Crawford County...with an observer in Robinson measuring 4.65. Due to excessive rainfall rates, flash flooding developed in both communities.
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 3, 9:33 AM CST, 1 hour 27 minutes earlier.
Area Forecast Discussion National Weather Service Lincoln IL 1033 AM CDT Mon Aug 3 2020 .SYNOPSIS... Issued at 309 AM CDT Mon Aug 3 2020 Cooler temperatures return today, as a weak boundary lingers across southern Illinois. This boundary will allow for the chance of showers and isolated thunderstorms, mainly near and south of the I-70 corridor...although a few showers could reach the I-72 corridor. Dry conditions arrive tonight, and continue through mid-week, as temperatures remain below average through Thursday. && .UPDATE... Issued at 1032 AM CDT Mon Aug 3 2020 Lots of clouds remains across most of the CWA, with some sunshine across eastern and southeastern IL. The upper level wave is still progressing across the area, so isolated showers will remain possible this afternoon with isolated thunderstorms possible in the east and southeast where sunshine will allow some instability to develop. Current forecast has a good handle on all this at this time, so no update is planned at this time. && .SHORT TERM...(Today and tonight) ISSUED AT 309 AM CDT Mon Aug 3 2020 Clear skies have once again overspread throughout much of central Illinois tonight, and even filtered into portions of southeast Illinois. Some light fog is being reported early this morning, mainly along where rainfall occurred yesterday, and just north of the boundary. The weak frontal boundary is located almost along the I-70 corridor currently, and is expected to linger there throughout today, before slowly moving east and dissipating. With this boundary remaining across portions of southeast Illinois today, should see some redevelopment of shower activity late through the morning into the afternoon. A weak vort wave will slide across the boundary producing the opportunity for wet weather. Northwest of the I-72 corridor is forecast to remain dry, however some light showers could reach as far north as I-72. This is all driven by the same Low pressure system that has been impacting the ne quadrant of the CONUS for the past few days. With northerly winds today, increasing through the afternoon, temperatures will remain below average with highs ranging from the low 70s nw of the IL River Valley, to near 80 se of I-70. Precipitation exits the area overnight, setting up a few days of dry conditions...and more comfortable temperatures. .LONG TERM...(Tuesday through Sunday) ISSUED AT 309 AM CDT Mon Aug 3 2020 A quiet stretch of weather will arrive Tuesday, and continue through mid-week into the second half of the week. Temperatures will remain slightly below average with a mix of sun and clouds each day. Models have the next chance of wet weather arriving at the end of the week, however discrepancy exists with each model as to how strong the Low pressure system will be. Went ahead and tapered off some of the PoPs, due to the uncertain nature of model trends. One thing to note though, will be the signs pointing to an increase in temperatures next weekend. Looks like High pressure will once again build across the desert sw into the southern Plains Friday into Saturday, which will usher warmer temperatures back into the Midwest. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) Issued at 552 AM CDT Mon Aug 3 2020 Starting out the period with a stratus layer slipping into the area from the north. This will create IFR to LIFR conditions at all terminals for the first part of the morning, before ceilings lift back to MVFR category around 14-15z. Heading into midday and early afternoon, should see a slow increase of ceilings to hopefully VFR, although might be later as these events take longer than projected to clear out. Expecting to remain cloudy overnight as the northerly winds continue. Winds today will remain out of the north, increasing through the day, then decreasing again overnight. Could see some shower activity this afternoon as a weak wave slides along the stalled out boundary near to the I-70 corridor. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && UPDATE...Auten SYNOPSIS...Baker SHORT TERM...Baker LONG TERM...Baker AVIATION...Baker
Hazardous Weather Outlook National Weather Service Lincoln IL 1102 AM CDT Mon Aug 3 2020 ILZ027>031-036-037-040-041-047-049-050-041100- Cass-Fulton-Knox-Marshall-Mason-Morgan-Peoria-Schuyler-Scott- Stark-Tazewell-Woodford- 1102 AM CDT Mon Aug 3 2020 This Hazardous Weather Outlook is for portions of central Illinois and west central Illinois. .DAY ONE...THIS AFTERNOON AND TONIGHT... No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY... Occasional thunderstorms are possible Thursday night through Sunday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated through tonight. ILZ038-042>046-048-051>057-061>063-066>068-041100- Champaign-Christian-Clark-Coles-Crawford-Cumberland-De Witt- Douglas-Edgar-Effingham-Jasper-Logan-Macon-McLean-Menard-Moultrie- Piatt-Sangamon-Shelby-Vermilion- 1102 AM CDT Mon Aug 3 2020 This Hazardous Weather Outlook is for portions of central Illinois, east central Illinois and southeast Illinois. .DAY ONE...THIS AFTERNOON AND TONIGHT... A few thunderstorms are possible, mainly this afternoon and early evening. Severe weather is not anticipated, although brief heavy rain is possible. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY... Occasional thunderstorms are possible Friday through Sunday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated through tonight. ILZ071>073-041100- Clay-Lawrence-Richland- 1102 AM CDT Mon Aug 3 2020 This Hazardous Weather Outlook is for portions of southeast Illinois. .DAY ONE...THIS AFTERNOON AND TONIGHT... Scattered thunderstorms are possible, mainly this afternoon and evening. Severe weather is not anticipated, although locally heavy rain is possible. Minor flooding will continue on the Little Wabash River at Clay City and the Embarras River at Lawrenceville. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY... Occasional thunderstorms are possible Friday night through Sunday. Minor flooding will continue on the Little Wabash River at Clay City and the Embarras River at Lawrenceville the next few days. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated through tonight. Auten
The Evansville,IN radar (KVWX), 80 km away, was scanning. The volume nearest the first event began at 17:00 UTC.
2 flash flood. Local standard time, as filed.
Water was flowing across Blue Mound Road from surrounding fields, prompting the road to be barricaded. Flooding also occurred on Hanging Rock Road southwest of Flora.
Several roads were flooded in Robinson. In addition, the Tempco Products building flooded due to rising water from a nearby creek.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2020Every state in 2020This day in weather historyWarnings in Illinois, August 2020
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: 914864, 914865.