Alert archive / Illinois / Severe Thunderstorm Warnings in 2013
Severe Thunderstorm Warning 3, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Apr 9, 2013, 9:26 AM CDT for Boone County, McHenry County, Winnebago County, Illinois. It was in force for 34 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
- Apr 9, 2013, 9:26 AM CDT (14:26 UTC)
- Expired
- Apr 9, 2013, 10:00 AM CDT
- In force
- 34 min
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 50.0 mph
Counties Boone County, IL, McHenry County, IL, Winnebago County, IL
The radar
The Milwaukee radar (KMKX), 74 km from the middle of the area, began a volume at 14:25 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
Davenport, (KDVN), launched 12:00Z, 2.4 hours before the alert went out and 160 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 460 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km storm-relative helicity
- 291 m²/s²
- 0-3 km storm-relative helicity
- 425 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.1
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 Apr 9, 9:13 AM CDT, 13 minutes earlier.
Area forecast discussion, Apr 9, 9:13 AM CDT, 13 minutes before
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</html>Hazardous weather outlook, Apr 9, 5:10 AM CDT, 4 hours 16 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
510 AM CDT TUE APR 9 2013
ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
101015-
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-
510 AM CDT TUE APR 9 2013 /610 AM EDT TUE APR 9 2013/
THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
.DAY ONE...TODAY AND TONIGHT.
WEATHER HAZARDS EXPECTED:
DENSE FOG.
THUNDERSTORMS...THE MOST INTENSE MAY PRODUCE:
HAIL UP TO THE SIZE OF GOLF BALLS.
DAMAGING WINDS IN EXCESS OF 60 MPH.
VERY HEAVY RAIN.
AND FREQUENT CLOUD TO GROUND LIGHTNING.
AREAS AFFECTED AND TIMING:
PATCHY DENSE FOG IS LIKELY ALONG THE ILLINOIS LAKE MICHIGAN
SHORE...MAINLY THIS MORNING. DENSE FOG IS POSSIBLE
TONIGHT...ESPECIALLY NORTH OF INTERSTATE 80.
SCATTERED THUNDERSTORMS ARE EXPECTED EARLY THIS MORNING...MAINLY
NORTH OF INTERSTATE 80.
ADDITIONAL SCATTERED THUNDERSTORMS...WITH SOME POTENTIAL FOR
SEVERE WEATHER...MAY DEVELOP THIS AFTERNOON INTO EARLY THIS
EVENING...THE GREATEST POTENTIAL IS NORTH OF A PONTIAC TO
RENSSELAER LINE.
FINALLY...THUNDERSTORM CHANCES WILL INCREASE FROM WEST TO EAST
ACROSS THE OUTLOOK AREA AFTER 1 AM TONIGHT.
DISCUSSION:
SCATTERED THUNDERSTORMS WILL AFFECT PORTIONS OF FAR NORTHERN
ILLINOIS THIS MORNING WITH THE STRONGEST STORMS CAPABLE OF
PRODUCING SOME SMALL HAIL AND HEAVY DOWNPOURS.
A STRONG WARM FRONT WILL STALL OUT OVER THE REGION THIS
AFTERNOON WITH VERY WARM AND HUMID AIR ALONG AND SOUTH OF THE
FRONT. A WEAK UPPER LEVEL DISTURBANCE WILL TRACK INTO THE REGION
LATE THIS AFTERNOON AND EVENING...LEADING TO THE POTENTIAL FOR
ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP. GIVEN THE
FORECAST INSTABILITY AND STRONG WINDS ALOFT THE POTENTIAL WILL
EXIST FOR ANY STORMS THAT DO FORM TO BECOME SEVERE WITH THE
POTENTIAL FOR LARGE HAIL AND DAMAGING WINDS.
FINALLY...A LARGE AREA OF SHOWERS AND THUNDERSTORMS THAT FORM
OVER THE PLAINS THIS AFTERNOON COULD MOVE INTO MAINLY WESTERN
PORTIONS OF THE OUTLOOK AREA LATE TONIGHT. THE PRIMARY THREAT
FROM THUNDERSTORMS LATE TONIGHT WOULD BE HEAVY RAIN.
.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.
SOME PERIODS OF THUNDERSTORMS ARE LIKELY WEDNESDAY INTO WEDNESDAY
NIGHT. THE POTENTIAL DOES EXISTS FOR SOME OF THE THUNDERSTORMS TO
BECOME SEVERE...ESPECIALLY SOUTH OF INTERSTATE 80 WEDNESDAY
NIGHT. HEAVY RAINFALL TOTALS ARE POSSIBLE THROUGH THURSDAY...WHICH
COULD RESULT IN SOME POTENTIAL FOR LOCALIZED FLOODING AND RISES ON
AREA RIVERS AND STREAMS.
THERE IS ANOTHER CHANCE OF THUNDERSTORMS SATURDAY NIGHT THROUGH
SUNDAY NIGHT.
.SPOTTER INFORMATION STATEMENT...
SPOTTERS MAY BE NEEDED THIS AFTERNOON AND EVENING.
&&
COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO
LMZ740>745-101015-
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-
510 AM CDT TUE APR 9 2013
THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS NEARSHORE
WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE
MICHIGAN.
.DAY ONE...TODAY AND TONIGHT.
PERIODIC THUNDERSTORM CHANCES WILL EXIST THROUGH TONIGHT WITH SOME
POTENTIAL FOR SEVERE THUNDERSTORMS WITH WINDS OVER 35 KT AND LARGE
HAIL THIS AFTERNOON AND EVENING.
AREAS OF DENSE FOG ARE LIKELY.
.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.
PATCHY DENSE FOG IS LIKELY INTO WEDNESDAY MORNING.
PERIODS OF THUNDERSTORMS WILL CONTINUE WEDNESDAY AND WEDNESDAY
NIGHT WITH SOME POTENTIAL FOR SEVERE THUNDERSTORMS...MAINLY
WEDNESDAY NIGHT.
STRONG WINDS AND HIGH WAVES WILL LEAD TO HAZARDOUS CONDITIONS FOR
SMALL CRAFT ALONG THE ILLINOIS SHORE WEDNESDAY...AND ALONG THE
ILLINOIS AND INDIANA SHORE WEDNESDAY NIGHT 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-
870-872-874-876-878-101015-
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-
510 AM CDT TUE APR 9 2013
THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE OPEN WATERS OF LAKE
MICHIGAN.
.DAY ONE...TODAY AND TONIGHT.
SCATTERED THUNDERSTORMS ARE LIKELY THROUGH TONIGHT...ESPECIALLY
SOUTHERN PORTIONS OF THE LAKE.
AREAS OF DENSE FOG ARE LIKELY...ESPECIALLY SOUTHERN PORTIONS OF
THE LAKE.
.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.
PATCHY DENSE FOG IS LIKELY WEDNESDAY MORNING...ESPECIALLY SOUTH.
PERIODS OF THUNDERSTORMS ARE LIKELY WEDNESDAY AND WEDNESDAY
NIGHT...ESPECIALLY SOUTHERN PORTIONS OF THE LAKE.
GALE FORCE WINDS ARE POSSIBLE WEDNESDAY NIGHT INTO THURSDAY.
&&
COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO
IZZIIn the hours before
Special weather statement, Apr 9, 3:29 AM CDT, 5 hours 57 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 329 AM CDT TUE APR 9 2013 ILZ008-090900- OGLE IL- 329 AM CDT TUE APR 9 2013 ...SPECIAL WEATHER STATEMENT... AT 328 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM NEAR SHANNON...MOVING NORTHEAST AT 20 MPH. NICKEL SIZE HAIL...CONTINUOUS CLOUD TO GROUND LIGHTNING...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THIS STORM. CITIES AND TOWNS AFFECTED... FORRESTON... AND RURAL NORTHWEST OGLE COUNTY... PRECAUTIONARY/PREPAREDNESS ACTIONS... STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. HEAVY RAINFALL COULD LEAD TO STANDING WATER ON ROADWAYS AND POOR VISIBILITY. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED. && LAT...LON 4220 8969 4220 8940 4205 8969 4220 8970 TIME...MOT...LOC 0828Z 225DEG 17KT 4213 8973
Local storm report, Apr 9, 8:51 AM CDT, 35 minutes before
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</html>Special weather statement, Apr 9, 9:16 AM CDT, 10 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 |
|---|---|---|---|---|
| Apr 9, 12:20 AM CDT | Dense Fog Advisory | LOT | Lake | 11 hr |
| Apr 9, 12:22 AM CDT | Marine Dense Fog Advisory | LOT | 27 hr | |
| Apr 9, 3:29 AM CDT | Special Weather Statement | LOT | Ogle | 31 min |
| Apr 9, 9:16 AM CDT | Special Weather Statement | LOT | Winnebago | 29 min |
| Apr 9, 9:44 AM CDT | Small Craft Advisory | LOT | 4 days | |
| Apr 9, 9:48 AM CDT | River Flood Watch | LOT | Winnebago | 25 hr |
| Apr 9, 9:48 AM CDT | River Flood Watch | LOT | Winnebago | 25 hr |
| Apr 9, 9:48 AM CDT | River Flood Watch | LOT | Winnebago | 25 hr |
| Apr 9, 3:54 PM CDT | Gale Watch | LOT | 12 hr | |
| Apr 8, 7:35 PM CDT | Special Weather Statement | LOT | Benton | 25 min |
| Apr 8, 9:42 PM CDT | Special Weather Statement | LOT | Benton | 33 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 2013Every severe thunderstorm warning in 2013
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.