Clusters of thunderstorms developed along and just south of a warm front draped across south-central Illinois during the late morning and afternoon of May 27th. to Robinson line.
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.
Clusters of thunderstorms developed along and just south of a warm front draped across south-central Illinois during the late morning and afternoon of May 27th. The storms primarily impacted locations along and south of a Jacksonville...to Shelbyville...to Robinson line. Two brief tornadoes touched down in Clay County, with only minor damage reported. Elsewhere, scattered wind gusts of around 60mph downed a few trees and powerlines.
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 27, 4:38 AM CST, 4 hours 37 minutes earlier.
Area Forecast Discussion National Weather Service Lincoln IL 538 AM CDT Thu May 27 2021 .SYNOPSIS... Issued at 250 AM CDT Thu May 27 2021 A couple rounds of showers and thunderstorms are possible across central Illinois today. Some of these storms could be strong to severe. Temperatures will warm into the 70s north of I-72 and 80s to the south. Additional rain is possible Friday along with much cooler temperatures. Dry and mild weather conditions are expected over the weekend. && .SHORT TERM...(Today and tonight) ISSUED AT 250 AM CDT Thu May 27 2021 The possibility of severe storms is the main forecast challenge for today with big boom or bust potential. Early this morning, convection is ongoing across Nebraska and Kansas where a low level jet is helping to sustain storms overnight. This cluster of storms is expected to move ESE/SE along the instability gradient, possibly evolving more linearly and driving into portions of southern and central Illinois through the late morning and early afternoon hours. If this were to occur, the overall severe threat would be lower with this initial line of storms owing to lack of strong instability early in the day but some damaging wind gusts will still be possible. In addition, 00/06Z HRRR indicate that the outflow boundary will surge well to our south and greatly hamper mid/late afternoon destabilization as new storms form in response to low pressure moving across the state. The amount of afternoon recovery and destabilization is the main wild card that will drive the severe chances for a possible second round of storms this afternoon and evening. There are large differences in the global/regional models which are not carrying morning convection into central Illinois and are much slower with arrival of storms, versus the CAMs which remain more aggressive bringing early day storms east. Latest NAM, for example, which does not carry the initial line of storms across the state, paints a more ominous picture with strong afternoon destabilization of 2000-3000 J/kg that extends northward to roughly the I-72 corridor. Meanwhile, a narrow ribbon of stronger shear (0-6km of 40-50kt) superimposed on the far northern end of the instability supports organized convection including a supercell threat this afternoon. Will need to monitor upstream trends closely through the morning to see if more organized upscale growth into an MCS occurs and where it tracks. Should a picture paint out similar to the NAM solution, then all severe hazards would be in play later this afternoon, including a tornado threat depending on the eventual placement of warm frontal boundary progged to be draped across Illinois. Confidence in this is low at this time given how poorly the NAM and other regional/global models are handling conditions out the gate. Would tend to err on the side of the CAMs which paint an earlier, lower end, but still non-zero severe threat with a bowing lines of storms moving across the state midday. .LONG TERM...(Friday through Wednesday) ISSUED AT 250 AM CDT Thu May 27 2021 By Friday morning, surface low and the greatest thunderstorm chances will shift to our east, but trailing low level cyclonic flow and the mid level vort max will still have to pass through the are bringing additional chances for rain. Soundings show fairly shallow moisture profiles trapped under a strong 800mb inversion. This should lead to some lighter rain Friday with the highest PoPs focused north of I-72. Breezy northeast winds will contribute to much cooler conditions across central Illinois. Highs are expected to top out in the mid 50s near Galesburg to lower/mid 70s near Lawrenceville. High pressure will build into the Upper Midwest and Great Lakes over the weekend and continue to dominate the local weather pattern into at least Monday of next week. This will result in a dry period of weather Saturday through Monday. Temperatures will remain on the cool side with continued NE flow Saturday and Sunday, but temperatures will at least moderate as the air mass modifies. Expect highs in the mid 60s Saturday and then lower to mid 70s Sunday. More seasonable conditions are expected through the first half of next week. Upper flow turns more zonal next week with lower amplitude waves that will bring at least daily chances for precip, especially Tuesday and Wednesday. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 532 AM CDT Thu May 27 2021 Thunderstorms west of the terminals this morning are expected to spread across central Illinois this afternoon and evening. Southeast winds and VFR conditions will prevail ahead of the storms. Winds will become a little more uncertain as storms impacts the region, but should eventually set up out of the SW then NW this evening and overnight. MVFR and eventually IFR ceilings are also expected to overspread the region overnight. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...Deubelbeiss SHORT TERM...Deubelbeiss LONG TERM...Deubelbeiss AVIATION...Deubelbeiss
Hazardous Weather Outlook National Weather Service Lincoln IL 502 AM CDT Thu May 27 2021 ILZ036-040-041-047-281015- Cass-Fulton-Mason-Schuyler- 502 AM CDT Thu May 27 2021 This Hazardous Weather Outlook is for portions of central Illinois and west central Illinois. .DAY ONE...TODAY AND TONIGHT... Severe thunderstorms and locally heavy rain are possible from early this afternoon into early evening. Damaging winds, large hail and isolated tornadoes are possible. Minor flooding will continue along the Illinois River near Havana and Beardstown downstream. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY... Minor flooding will continue along the Illinois River at Havana and Beardstown, though subsiding Friday at Havana, and Monday at Beardstown. Thunderstorms are possible Tuesday night. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed between noon and 9 pm. Please relay any information about observed severe weather to the National Weather Service while following all local, state and CDC guidelines. ILZ027>031-037-038-042>046-048>057-061>063-066>068-071>073-281015- Champaign-Christian-Clark-Clay-Coles-Crawford-Cumberland-De Witt- Douglas-Edgar-Effingham-Jasper-Knox-Lawrence-Logan-Macon-Marshall- McLean-Menard-Morgan-Moultrie-Peoria-Piatt-Richland-Sangamon- Scott-Shelby-Stark-Tazewell-Vermilion-Woodford- 502 AM CDT Thu May 27 2021 This Hazardous Weather Outlook is for portions of central Illinois, east central Illinois, southeast Illinois and west central Illinois. .DAY ONE...TODAY AND TONIGHT... Severe thunderstorms and locally heavy rain are possible from early this afternoon into early evening. Damaging winds, large hail and isolated tornadoes are possible. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY... Thunderstorms are possible Tuesday night. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed between noon and 9 pm. Please relay any information about observed severe weather to the National Weather Service while following all local, state and CDC guidelines. 25
Special Weather Statement National Weather Service Lincoln IL 1013 AM CDT Thu May 27 2021 ILZ047-048-050-051-271545- Sangamon-Morgan-Menard-Cass- 1013 AM CDT Thu May 27 2021 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN MENARD... NORTHWESTERN SANGAMON...SOUTHEASTERN CASS AND NORTHEASTERN MORGAN COUNTIES UNTIL 1045 AM CDT... At 1012 AM CDT, Doppler radar was tracking a strong thunderstorm near Alexander, or near Jacksonville, moving northeast at 50 mph. Pea size hail and wind gusts of 50 to 55 mph will be possible with this storm. Locations impacted include... Springfield, Jacksonville, Alexander, Petersburg, Athens, New Berlin, Ashland, Pleasant Plains, Woodson, Tallula, Literberry, South Jacksonville, Jerome, Southern View, Leland Grove, Philadelphia, Curran, Berlin, Newmansville and Sinclair. This includes the following highways... Interstate 55 near mile marker 95. Interstate 72 between mile markers 62 and 96, and near mile marker 101. LAT...LON 3960 9025 3983 9035 4009 8984 3976 8959 TIME...MOT...LOC 1512Z 240DEG 43KT 3978 9013 37
The Lincoln radar (KILX), 89 km away, was scanning. The volume nearest the first event began at 15:14 UTC.
7 thunderstorm wind, 2 tornado. Local standard time, as filed.
A few trees and power lines were blown down.
Trees and power lines were blown onto a roadway near Southern View.
Numerous tree limbs were blown down.
A few trees were damaged near Riverton.
A power pole was leaning due to strong thunderstorm wind gusts.
A power line was blown down.
A tornado touched down in an open field about 2.9 miles east-southeast of Louisville at 3:29 PM CDT before quickly dissipating at 3:31 PM CDT. No damage was observed.
A tree was blown onto a car.
A tornado touched down 1.8 miles southeast of Sailor Springs at 3:43 PM CDT. The tornado tracked southeastward and knocked down a few trees and did minor damage to a barn before dissipating at 3:49 PM CDT about 4.6 miles southeast of Sailor Springs.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2021Every state in 2021This day in weather historyThe tornado archive for Illinois, 2021Warnings in Illinois, May 2021
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: 958053, 958054, 958055, 958056, 958057, 958058, 958051, 958059, 958052.