A cold front triggered a broken line of thunderstorms across Iowa and Missouri during the afternoon of May 21st: however, these cells dissipated as they crossed the Mississippi River into a much drier environment across central Illinois. Additional scattered showers and thunderstorms developed further east during the evening and were able to transport higher momentum air aloft down to the surface.
Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 cold front triggered a broken line of thunderstorms across Iowa and Missouri during the afternoon of May 21st: however, these cells dissipated as they crossed the Mississippi River into a much drier environment across central Illinois. Additional scattered showers and thunderstorms developed further east during the evening and were able to transport higher momentum air aloft down to the surface. Gradient wind gusts were generally 40-50mph, but sporadic gusts as high as 55-65mph were reported in and near the developing showers and storms. As a result, scattered wind damage was reported across the area.
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 May 21, 5:42 PM CST, 25 minutes earlier. Its key messages:
Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 642 PM CDT Tue May 21 2024 .KEY MESSAGES... - Strong south winds will gust up to 40 mph into early this evening. This will create blowing dust in spots where fields have recently been plowed. - There is a level 4 of 5 (moderate) risk for severe weather this evening west of the Illinois River, with gradually lower chances further east. While all severe hazards are in play, the greatest risks will be damaging wind gusts and brief tornadoes. A level 1 of 5 (marginal) risk will linger south of I-70 tomorrow afternoon. - An active pattern continues into this weekend with another risk of severe storms on Sunday. && .DISCUSSION... Issued at 211 PM CDT Tue May 21 2024 18z surface map placed 996 mb low pressure over extreme southeast Nebraska, which is forecast to deepen as it tracks northeast into northern WI tonight. Well within the warm sector this afternoon, central IL is being bathed in summertime heat and humidity with temperatures in the upper 80s and dewpoints in the mid 60s as of 1 pm. A tight MSLP gradient will promote 30-40 mph southerly winds gusts into early this evening. Dry top layers of soil and active farming activity will lead to blowing dust in spots through late afternoon. A warm layer aloft centered near 775 mb should keep convection suppressed in the warm sector this afternoon, and our attention is focused on the cold front trailing south of the low, which is forecast to fill in with convection over the next few hours. With the better kinematic fields lifting northeast along with the surface low, mesoanalysis suggests the more significant severe weather potential (long track tornadoes, very large hail, widespread wind damage) affecting areas to our northwest across IA, far northwest IL, and southern WI into this evening. We do maintain a risk of severe storms this evening locally, particularly west of I-55 in a 7 to 11 pm window. As the line of storms moves into this area, strong deep layer shear and moderate instability will favor damaging straight line wind gusts in the more intense line segments. While instability will decrease with time and eastward extent, a 925-850 mb jet will strengthen overhead, which may keep the severe threat going toward midnight or a little later than the CAMs have been trending. The tornado risk will mainly be tied to QLCS tornadoes, based on favorable 0-3km shear vectors northwest of the IL River. Behind the front, a more typical May airmass will filter into most of central later tonight and Wednesday with cooler highs in the 70s and lower humidity. The exception will be south of I-70 where the front is slower to clear, leading to another warm day and a few afternoon storms. The severe weather risk is much reduced in this area from previous forecasts with higher instability (CAPEs 1000+ J/kg) suppressed near and south of the Ohio River based on the 12z HREF. Still a couple strong afternoon storms can't be ruled out given 30 kt deep layer shear and SPC has a Marginal risk (level 1/5) near/south of I-70. For Thursday through early next week an active pattern will remain in place across the region, with shortwaves shown crossing the Midwest every 36-48 hours. Significant uncertainty in the forecast details exist given differences in timing and placement of these features, however Friday and Sunday look to be the favored periods for more widespread showers and storms and this is where higher PoPs have been placed. For severe weather prospects, Sunday is currently the most concerning, especially if the 21/12z ECMWF verifies with low pressure deepening just to our northwest. Again, widely varying solutions are noted in the ensemble envelope, so keep updated on later forecasts as the pattern evolves. 25 && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 641 PM CDT Tue May 21 2024 South winds will gust 30-40 kt into this evening ahead of a cold front. A broken line of TSRA is expected to cross the central IL terminals this evening, and have a 3-hr tempo for IFR conditions and gusty winds associated with the storms. Winds veer west behind the frontal passage and lose gustiness. Patchy MVFR ceilings could develop behind the front, primarily at KBMI-KDEC-KCMI and have added a scattered cloud group there for the overnight hours. Shimon && .ILX WATCHES/WARNINGS/ADVISORIES... None. &&
Hazardous Weather Outlook National Weather Service Lincoln IL 308 PM CDT Tue May 21 2024 ILZ027>031-036-037-040-041-047>050-222015- Knox-Stark-Peoria-Marshall-Woodford-Fulton-Tazewell-Schuyler-Mason- Cass-Menard-Scott-Morgan- 308 PM CDT Tue May 21 2024 This Hazardous Weather Outlook is for central Illinois and west central Illinois. .DAY ONE...Tonight. Severe thunderstorms are likely across the area this evening. Wind gusts over 70 mph, large hail, and tornadoes are all possible. Ahead of the storms, south winds will gust up to 40 mph, creating blowing dust into early this evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Chances for thunderstorms return Thursday night, and persist through the holiday weekend. The severe weather threat is uncertain at this time. Minor flooding will linger on the Illinois River near Havana and Beardstown for several days. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed between 7 pm and 10 pm. Expected storm motion is toward the northeast around 45 mph. ILZ038-042-043-051>053-222015- McLean-Logan-De Witt-Sangamon-Christian-Macon- 308 PM CDT Tue May 21 2024 This Hazardous Weather Outlook is for central Illinois. .DAY ONE...Tonight. Severe thunderstorms are likely to move across the area this evening. Wind gusts of 60 to 70 mph and hail are possible, along with a tornado or two. Ahead of the storms, south winds will gust up to 40 mph, creating blowing dust into early this evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Chances for thunderstorms return Thursday night, and persist through the holiday weekend. The severe weather threat is uncertain at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed between 8 pm and 11 pm. Expected storm motion is toward the east around 45 mph. ILZ044>046-054>057-061>063-066-067-071-222015- Piatt-Champaign-Vermilion-Moultrie-Douglas-Coles-Edgar-Shelby- Cumberland-Clark-Effingham-Jasper-Clay- 308 PM CDT Tue May 21 2024 This Hazardous Weather Outlook is for central Illinois, east central Illinois and southeast Illinois. .DAY ONE...Tonight. Thunderstorms are expected to move into the area late this evening. Some may be severe, with damaging winds around 60 mph the main concern. Ahead of the storms, south winds will gust up to 40 mph, creating blowing dust into early this evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Thunderstorm chances remain in the forecast much of this period. The severe weather threat is uncertain at this time, but would be more favored on Sunday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed between 10 pm and 1 am. Expected storm motion is toward the east around 45 mph. ILZ068-072-073-222015- Crawford-Richland-Lawrence- 308 PM CDT Tue May 21 2024 This Hazardous Weather Outlook is for southeast Illinois. .DAY ONE...Tonight. Scattered thunderstorms will begin moving into the area late this evening, with better chances after midnight. A few may be strong to locally severe, though this is more likely north of I-70. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Thunderstorms are possible again on Wednesday, and a few of them may contain strong winds. However, the greater severe weather threat will be further south. Chances for storms will continue into the holiday weekend. The best chance for severe weather currently appears to be on Sunday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed after midnight. 25
Special Weather Statement National Weather Service Lincoln IL 220 PM CDT Tue May 21 2024 ILZ027>031-036>038-040>057-061-212200- 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- Including the cities of Galesburg, Toulon, Peoria, Lacon, Eureka, Canton, Pekin, Bloomington, Normal, Rushville, Havana, Lincoln, Clinton, Monticello, Champaign, Urbana, Danville, Beardstown, Petersburg, Winchester, Jacksonville, Springfield, Taylorville, Decatur, Sullivan, Tuscola, Charleston, Mattoon, Paris, and Shelbyville 220 PM CDT Tue May 21 2024 ...Gusty South Winds And Blowing Dust This Afternoon... South winds will gust up to 40 mph this afternoon. This will create difficult travel for high profile, lightweight vehicles, especially on east west roads. In addition, dry topsoil and recently plowed fields will lead to areas of blowing dust. This can create sharply reduced visibility over short distances in rural areas. 25
The Lincoln radar (KILX), 97 km away, was scanning. The volume nearest the first event began at 00:57 UTC.
13 thunderstorm wind, 4 strong wind. Local standard time, as filed.
Several 2-inch diameter tree branches were blown down due to non-thunderstorm wind gusts 1 mile west-northwest of Savoy.
A trained spotter estimated a wind gust of 65mph.
A power line was brought down by a large tree that fell in Creve Coeur due to a non-thunderstorm wind gust.
Large seed boxes were toppled and several tree branches were blown down on a farm south of Moweaqua.
A large tree was blown down onto a house in Washington due to a non-thunderstorm wind gust.
A tree was blown down across Highway 19 and 1600 East just west of Findlay.
A light pole was snapped.
A 1-foot diameter tree limb was blown down.
Several tree limbs were blown down and some siding was torn off a house.
A member of the media estimated a wind gust of 60mph.
Several large tree branches were blown down, including a large section of a maple tree leaning on an 80-foot sycamore tree.
A few trees and power lines were blown down.
A few trees were blown down.
A 58mph wind gust was measured at AWOS station KTIP.
A 60mph wind gust was measured at ASOS station KCMI.
A 62mph wind gust was measured at mesonet station FW0668.
A large tree limb was blown down in Danville due to a non-thunderstorm wind gust.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2024Every state in 2024This day in weather historyWarnings in Illinois, May 2024
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: 1171576, 1171569, 1171577, 1171558, 1171580, 1171559, 1171560, 1171561, 1171563, 1171570, 1171565, 1171566, 1171567, 1171571, 1171572, 1171573, 1171579.