Alert archive / Illinois / Severe Thunderstorm Warnings in 2014

Severe Thunderstorm Warning 8, NWS Chicago, IL

May 11, 2014Lee County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at May 11, 2014, 3:48 PM CDT for Lee County, Illinois. 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: May 11, 2014, 3:48 PM CDT (20:48 UTC)
Expired: May 11, 2014, 4:45 PM CDT
In force: 57 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Lee County, IL

The radar

The Chicago radar (KLOT), 102 km from the middle of the area, began a volume at 20:49 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 11, 3:05 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.8 hours before the alert went out and 101 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 52 J/kg
Mixed-layer CIN: -261 J/kg
Mixed-layer LCL: 1382 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 140 m²/s²
0-3 km storm-relative helicity: 162 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 May 11, 3:38 PM CDT, 10 minutes earlier.

Area forecast discussion, May 11, 3:38 PM CDT, 10 minutes before

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Hazardous weather outlook, May 11, 10:44 AM CDT, 5 hours 4 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1044 AM CDT SUN MAY 11 2014

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
121545-
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-
1044 AM CDT SUN MAY 11 2014 /1144 AM EDT SUN MAY 11 2014/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

  WEATHER HAZARDS EXPECTED:

  SCATTERED THUNDERSTORMS...SOME COULD BE SEVERE WITH:
    HAIL UP TO THE SIZE OF GOLF BALLS.
    DAMAGING WINDS OVER 60 MPH.
    TORRENTIAL DOWNPOURS.
    FREQUENT LIGHTNING.
    ALONG WITH SOME TORNADO POTENTIAL.

  AREAS AFFECTED AND TIMING:

  SCATTERED THUNDERSTORMS WILL LIKELY DEVELOP BETWEEN 2 PM AND 5
  PM WITH THE HIGHEST CHANCES FOR INITIAL DEVELOPMENT BEING SOUTH
  OF INTERSTATES 88 AND 290. STORMS WILL LIKELY MOVE NORTHEAST
  OR EAST. THE SEVERE THUNDERSTORM THREAT APPEARS HIGHEST BETWEEN
  3 PM AND 9 PM...WITH A CHANCE OF MAINLY NON-SEVERE THUNDERSTORMS
  LINGERING THROUGH TONIGHT.

  DISCUSSION:

  A WARM FRONT WILL LIFT NORTH INTO NORTHERN ILLINOIS EARLY THIS
  AFTERNOON WITH THE ATMOSPHERE BECOMING QUITE UNSTABLE IN ADVANCE
  OF AND NEAR THIS WARM FRONT. SCATTERED THUNDERSTORMS ARE
  EXPECTED TO DEVELOP BY MID AFTERNOON AND CONTINUE INTO THE MID
  EVENING HOURS. WINDS ALOFT ARE FORECAST TO BECOME INCREASINGLY
  FAVORABLE FOR SEVERE THUNDERSTORMS...SO THAT ANY STORMS THAT DO
  DEVELOP COULD EASILY BECOME SEVERE LATE THIS AFTERNOON INTO VERY
  EARLY THIS EVENING. THE PRIMARY HAZARD APPEARS TO BE LARGE
  HAIL...POSSIBLY UP TO THE SIZE OF GOLF BALLS OR PERHAPS A BIT
  LARGER IN SPOTS. THERE ARE INDICATIONS THAT THERE COULD BE A
  WINDOW OF OPPORTUNITY FOR THUNDERSTORMS TO POTENTIALLY BECOME
  TORNADIC...ESPECIALLY BETWEEN 4 PM AND 8 PM THIS EVENING.

  WHILE SOME LINGERING CHANCE OF STORMS WILL CONTINUE
  LATE THIS EVENING AND OVERNIGHT...THE GREATEST FOCUS FOR
  THUNDERSTORM DEVELOPMENT WILL LIKELY SHIFT NORTH INTO WISCONSIN.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THERE IS A CHANCE OF THUNDERSTORMS MONDAY WITH THE THREAT
INCREASING MONDAY NIGHT. THERE DOES APPEAR TO BE SOME LIMITED
THREAT OF ISOLATED SEVERE THUNDERSTORMS MONDAY NIGHT...MAINLY
WEST TOWARD THE INTERSTATE 39 CORRIDOR. THERE IS A SLIGHT CHANCE
THAT THUNDERSTORMS COULD LINGER INTO TUESDAY MORNING...ESPECIALLY
OVER NORTHWEST INDIANA.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ACTIVATION MAY BE NEEDED FROM MID AFTERNOON THROUGH MID
EVENING.

&&

LMZ740>745-121545-
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-
1044 AM CDT SUN MAY 11 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS NEARSHORE
WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE
MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON INTO EARLY
THIS EVENING...WITH A LESSER CHANCE OF THUNDERSTORMS LINGERING
THROUGH OVERNIGHT. SOME OF THE STORMS COULD PRODUCE LARGE HAIL
AND WIND GUSTS OVER 35 KNOTS THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS MONDAY...WITH THE
THREAT OF THUNDERSTORMS INCREASING MONDAY NIGHT AND POTENTIALLY
LINGERING INTO TUESDAY MORNING. SOME THREAT DOES EXISTS FOR
THUNDERSTORMS MONDAY NIGHT TO PRODUCE WIND GUSTS OVER 35 KNOTS.

STRONG WINDS WILL LEAD TO HAZARDOUS CONDITIONS FOR SMALL CRAFT
MONDAY.

&&

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-121545-
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-
1044 AM CDT SUN MAY 11 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE OPEN WATERS OF LAKE
MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS ARE POSSIBLE OVER SOUTHERN PORTIONS OF THE LAKE
LATER THIS AFTERNOON WITH THE THREAT SPREADING NORTH ACROSS THE
LAKE TONIGHT. SOME OF THE STORMS COULD PRODUCE LARGE HAIL AND WIND
GUSTS OVER 35 KNOTS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THUNDERSTORMS ARE POSSIBLE MONDAY THROUGH TUESDAY MORNING...SOME
MAY BE SEVERE.

DENSE FOG IS POSSIBLE MONDAY AND MONDAY NIGHT.

&&

IZZI/MTF

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO

In the hours before

Local storm report, May 11, 3:03 PM CDT, 45 minutes before

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Local storm report, May 11, 3:05 PM CDT, 43 minutes before

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Local storm report, May 11, 3:08 PM CDT, 40 minutes before

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Local storm report, May 11, 3:15 PM CDT, 33 minutes before

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Local storm report, May 11, 3:27 PM CDT, 21 minutes before

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Local storm report, May 11, 3:32 PM CDT, 16 minutes before

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The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 11, 2:54 PM CDT	Severe Thunderstorm Warning	LOT	Boone, McHenry, Winnebago	66 min
May 11, 3:19 PM CDT	Severe Thunderstorm Warning	LOT	Boone, Ogle, Winnebago	56 min
May 11, 4:02 PM CDT	Severe Thunderstorm Warning	LOT	Boone, McHenry, Winnebago	58 min
May 11, 4:32 PM CDT	Severe Thunderstorm Warning	LOT	Lake, McHenry	58 min
May 11, 4:36 PM CDT	Severe Thunderstorm Warning	LOT	DuPage, Kane	54 min
May 11, 4:50 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle, Livingston	55 min
May 11, 5:01 PM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois, Livingston	59 min
May 11, 5:14 PM CDT	Special Marine Warning	LOT		2 hr
May 11, 5:15 PM CDT	Severe Thunderstorm Warning	LOT	Lake, McHenry	45 min
May 11, 5:26 PM CDT	Severe Thunderstorm Warning	LOT	Ford, Grundy, Iroquois, Kankakee, Kendall, Livingston and 1 more	64 min
May 11, 5:44 PM CDT	Severe Thunderstorm Warning	LOT	Grundy, Kendall, LaSalle, Livingston	61 min
May 11, 5:50 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	55 min
May 11, 5:52 PM CDT	Special Marine Warning	LOT		113 min
May 11, 6:10 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Kendall, Will	35 min
May 11, 6:20 PM CDT	Areal Flood Advisory	LOT	Cook, DeKalb, DuPage, Ford, Grundy, Iroquois and 6 more	3 hr
May 11, 6:32 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Will	58 min
May 11, 6:57 PM CDT	Flash Flood Warning	LOT	Cook, Ford, Grundy, Iroquois, Kankakee, Kendall and 2 more	4 hr
May 11, 6:19 PM CDT	Severe Thunderstorm Warning	LOT	Jasper, Lake, Newton, Porter	56 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2014 Every severe thunderstorm warning in 2014

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.