Alert archive / Illinois / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 127, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Jul 23, 2011, 9:18 PM CDT for Iroquois County, Illinois; Benton County, Indiana. It was in force for 57 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jul 23, 2011, 9:18 PM CDT (02:18 UTC)
- Expired
- Jul 23, 2011, 10:15 PM CDT
- In force
- 57 min
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Hail
- 0.5 in
- Wind
- 60.0 mph
Counties Iroquois County, IL, Benton County, IN
The radar
The Chicago radar (KLOT), 112 km from the middle of the area, began a volume at 02:19 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 2.3 hours before the alert went out and 105 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 2467 J/kg
- Mixed-layer CIN
- -38 J/kg
- Mixed-layer LCL
- 1436 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 47 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.7
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Chicago, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 23, 7:05 PM CDT, 2 hours 13 minutes earlier.
Area forecast discussion, Jul 23, 7:05 PM CDT, 2 hours 13 minutes before
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</html>Hazardous weather outlook, Jul 23, 5:03 PM CDT, 4 hours 15 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 503 PM CDT SAT JUL 23 2011 ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019- 242215- WINNEBAGO-BOONE-MCHENRY-LAKE ILLINOIS-OGLE-LEE-DE KALB-KANE- DUPAGE-COOK-LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON- IROQUOIS-FORD-LAKE INDIANA-PORTER-NEWTON-JASPER-BENTON- 503 PM CDT SAT JUL 23 2011 /603 PM EDT SAT JUL 23 2011/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS... NORTHEAST ILLINOIS AND NORTHWEST INDIANA. .DAY ONE...TONIGHT. WEATHER HAZARDS EXPECTED: THUNDERSTORMS...SOME MAY PRODUCE: HEAVY RAINFALL WITH FLASH FLOODING. FREQUENT LIGHTNING. DAMAGING WINDS IN EXCESS OF 60 MPH. OPPRESSIVE HEAT AND HUMIDITY. AREAS AFFECTED AND TIMING: SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS EVENING ACROSS PORTIONS OF NORTHWESTERN INDIANA. ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS PORTIONS OF NORTHERN ILLINOIS FROM EASTERN IOWA THIS EVENING. A SECOND AREA OF THUNDERSTORMS MAY DEVELOP LATER THIS EVENING ACROSS NORTHERN IOWA. SHOULD THESE THUNDERSTORMS DEVELOP...THE COMPLEX OF THUNDERSTORMS COULD TRACK ACROSS NORTHERN ILLINOIS AND NORTHWESTERN INDIANA LATER TONIGHT. IT APPEARS THAT THE BEST AREAS THAT MAY BE IMPACTED BY THESE THUNDERSTORMS WILL BE SOME OF THE SAME AREAS ALREADY HIT BY HEAVY RAINFALL OVER THE PAST FEW DAYS. THE DANGEROUS HEAT AND HUMIDITY WILL CONTINUE...ESPECIALLY SOUTH OF INTERSTATE 80. DISCUSSION: DUE TO THE HEAVY RAINFALL PRODUCED THIS MORNING ACROSS NORTHERN ILLINOIS AND THE FACT THAT ADDITIONAL HEAVY RAINFALL IS POSSIBLE LATER TONIGHT INTO SUNDAY ACROSS THE SAME AREAS...THERE IS A HIGH THREAT FOR ADDITIONAL FLASH FLOODING. MUCH IF NOT ALL OF ANY RAINFALL THAT FALLS ACROSS NORTHERN ILLINOIS WILL BE CONVERTED TO RUNOFF DUE TO THE SATURATED GROUND. THIS RUNOFF COULD EASILY OVERWHELM SMALL STREAMS AND DRAINAGE BASINS. ALSO DUE TO THE HEAVY RAINFALL OVER THE PAST 48 HOURS LOCATIONS ON THE DES PLAINES RIVER HAVE RAPIDLY REACHED FLOOD STAGE AND WILL CONTINUE TO RISE THROUGH THIS EVENING. LOCATIONS ALONG AND SOUTH OF INTERSTATE 80 SHOULD SEE VERY WARM TEMPERATURES TONIGHT...WITH LOWS ONLY DROPPING INTO THE MID TO UPPER 70S. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. LOCATIONS SOUTH OF INTERSTATE 80 WILL SEE HEAT INDEX VALUES OF 110 TO 115 DEGREES ON SUNDAY. LOCATIONS ALONG THE INTERSTATE 80 CORRIDOR WILL SEE HEAT INDEX VALUES OF AROUND 105 TO 110 DEGREES ON SUNDAY. THERE WILL BE PERIODIC CHANCES FOR THUNDERSTORMS SUNDAY AND AGAIN WEDNESDAY THROUGH FRIDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NECESSARY THROUGH TONIGHT...ESPECIALLY FOR FLASH FLOODING. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO LMZ740>745-242215- WINTHROP HARBOR TO WILMETTE HARBOR- WILMETTE HARBOR TO NORTHERLY ISLAND- NORTHERLY ISLAND TO CALUMET HARBOR-CALUMET HARBOR TO GARY- GARY TO BURNS HARBOR-BURNS HARBOR TO MICHIGAN CITY- 503 PM CDT SAT JUL 23 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS NEARSHORE WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE MICHIGAN. .DAY ONE...TONIGHT. THERE IS A CHANCE OF STORMS CAUSING WIND GUSTS IN EXCESS OF 35 KNOTS AND FREQUENT LIGHTNING. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. THERE WILL BE PERIODIC CHANCES FOR THUNDERSTORMS SUNDAY AND AGAIN WEDNESDAY THROUGH FRIDAY. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868- 870-872-874-876-878-242215- LAKE MICHIGAN FROM MICHIGAN CITY IN TO ST. JOSEPH MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM SEUL CHOIX POINT TO ROCK ISLAND PASSAGE 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN SOUTH OF A LINE FROM SEUL CHOIX POINT TO THE MACKINAC BRIDGE AND NORTH OF A LINE FROM CHARLEVOIX MI TO SOUTH FOX ISLAND 5 NM OFFSHORE- LAKE MICHIGAN FROM CHARLEVOIX TO POINT BETSIE MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM POINT BETSIE TO MANISTEE MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM ROCK ISLAND PASSAGE TO STURGEON BAY WI- LAKE MICHIGAN FROM STURGEON BAY TO TWO RIVERS WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM TWO RIVERS TO SHEBOYGAN WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM SHEBOYGAN TO PORT WASHINGTON WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM PORT WASHINGTON TO NORTH POINT LIGHT WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM NORTH POINT LIGHT TO WIND POINT WI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM WIND POINT WI TO WINTHROP HARBOR IL 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM WINTHROP HARBOR TO WILMETTE HARBOR IL 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM WILMETTE HARBOR IL TO MICHIGAN CITY IN 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM PENTWATER TO MANISTEE MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM WHITEHALL TO PENTWATER MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM GRAND HAVEN TO WHITEHALL MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM HOLLAND TO GRAND HAVEN MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM SOUTH HAVEN TO HOLLAND MI 5 NM OFFSHORE TO MID LAKE- LAKE MICHIGAN FROM ST. JOSEPH TO SOUTH HAVEN MI 5 NM OFFSHORE TO MID LAKE- 503 PM CDT SAT JUL 23 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE OPEN WATERS OF LAKE MICHIGAN. .DAY ONE...TONIGHT. THERE IS A CHANCE OF STORMS CAUSING WIND GUSTS IN EXCESS OF 35 KNOTS AND FREQUENT LIGHTNING. THE STRONGEST STORMS ARE LIKELY OVER THE SOUTHERN PORTIONS OF THE LAKE. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. THERE WILL BE PERIODIC CHANCES FOR THUNDERSTORMS SUNDAY AND AGAIN TUESDAY NIGHT THROUGH FRIDAY. && COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO KJB
In the hours before
Special weather statement, Jul 23, 5:27 PM CDT, 3 hours 51 minutes before
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</html>Local storm report, Jul 23, 5:33 PM CDT, 3 hours 45 minutes before
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</html>The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 23, 8:57 PM CDT | Areal Flood Advisory | LOT | Iroquois | 4 hr |
| Jul 23, 11:27 PM CDT | Special Weather Statement | LOT | Cook, DeKalb, DuPage, Kane | 63 min |
| Jul 23, 11:43 PM CDT | Flash Flood Warning | LOT | Cook, DeKalb, DuPage, Grundy, Kane, Kendall and 2 more | 6 hr |
| Jul 24, 5:51 AM CDT | Special Weather Statement | LOT | Lee, Ogle, Winnebago | 24 min |
| Jul 24, 6:19 AM CDT | Severe Thunderstorm Warning | LOT | Boone, DeKalb, Kane, Kendall, Lee, McHenry and 2 more | 56 min |
| Jul 24, 6:44 AM CDT | Severe Thunderstorm Warning | LOT | DeKalb, Grundy, Kendall, LaSalle, Lee, Livingston | 47 min |
| Jul 24, 8:16 AM CDT | Severe Thunderstorm Warning | LOT | Ford, Iroquois, Kankakee, Livingston, Will | 59 min |
| Jul 24, 8:26 AM CDT | Flash Flood Warning | LOT | Cook, Kane, Kendall, Will | 106 min |
| Jul 24, 8:31 AM CDT | Special Weather Statement | LOT | DuPage | 29 min |
| Jul 24, 8:54 AM CDT | River Flood Advisory | LOT | Kane, Kendall | 11 hr |
| Jul 24, 10:07 AM CDT | Areal Flood Warning | LOT | Cook, Kane, Kendall, Will | 6 hr |
| Jul 24, 9:19 AM CDT | Special Weather Statement | LOT | Benton, Jasper, Newton | 41 min |
| Jul 24, 9:47 AM CDT | Special Weather Statement | LOT | Benton, Jasper | 13 min |
| Jul 24, 5:43 PM CDT | Rip Current Statement | LOT | Lake, Porter | 13 hr |
Nearby
Severe Thunderstorm Warnings in Illinois, 2011Severe Thunderstorm Warnings in Indiana, 2011Every severe thunderstorm warning in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.