Alert archive / Illinois / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 90, NWS Chicago, IL

July 13, 2015LaSalle County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 13, 2015, 4:59 PM CDT for LaSalle County, Illinois. It was in force for 61 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 13, 2015, 4:59 PM CDT (21:59 UTC)
Expired
Jul 13, 2015, 6:00 PM CDT
In force
61 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

County LaSalle County, IL

The radar

The Chicago radar (KLOT), 73 km from the middle of the area, began a volume at 22:02 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.

IssuedProductOfficeLasted
Jul 13, 4:01 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.0 hours before the alert went out and 135 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-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2015-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2535 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2015-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
2535 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
1016 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
1.9
Supercell composite
10.6

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 Jul 13, 4:33 PM CDT, 26 minutes earlier.

Area forecast discussion, Jul 13, 4:33 PM CDT, 26 minutes before
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Hazardous weather outlook, Jul 13, 4:37 PM CDT, 22 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
437 PM CDT MON JUL 13 2015

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
142145-
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-
437 PM CDT MON JUL 13 2015

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

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

   THUNDERSTORMS...SOME MAY BE SEVERE AND MAY PRODUCE:

    EXTREME WIND GUSTS TO 80 MPH.
    HAIL TO AT LEAST GOLF BALL SIZE.
    TORNADOES...INCLUDING A STRONG TORNADO OR TWO.
    TORRENTIAL DOWNPOURS AND FLASH FLOODING.

  AREAS AFFECTED AND TIMING:

  THROUGH LATE THIS EVENING ACROSS THE OUTLOOK AREA.

  DISCUSSION:

A VERY MOIST AND UNSTABLE ENVIRONMENT WILL ALLOW EXPLOSIVE
THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON THROUGH THIS EVENING.
ANY DISCRETE STORM COULD PRODUCE A STRONG TORNADO OR TWO...AND
LARGE TO VERY LARGE HAIL WILL ALSO BE POSSIBLE. IF EVOLUTION TO
ONE OR MORE FAST MOVING THUNDERSTORM COMPLEXES OCCURS...THEN THE
THREAT WILL LIKELY EVOLVE TO WIDESPREAD HIGH END DAMAGING
WINDS...WITH AN ISOLATED TORNADO AND HAIL THREAT. A VERY MOIST
AIRMASS WILL REMAIN IN PLACE THROUGH TONIGHT...SO ANY INTENSE
THUNDERSTORM WILL PRODUCE EXCESSIVE RAINFALL RATES AND THE
POTENTIAL FOR RAPID FLASH FLOODING.

PORTIONS OF THE ILLINOIS...IROQUOIS...VERMILLION AND KANKAKEE
RIVERS...AND SUGAR CREEK ARE IN FLOOD....WITH RENEWED RISES
POSSIBLE DUE TO ANY HEAVY RAIN TONIGHT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

DANGEROUS SWIMMING CONDITIONS MAY BE POSSIBLE TUESDAY EVENING
ALONG BOTH ILLINOIS AND INDIANA BEACHES.

THERE IS A CHANCE FOR THUNDERSTORMS ON TUESDAY AND THEN A
PERIODIC CHANCE OF THUNDERSTORMS THURSDAY THROUGH SUNDAY.

PORTIONS OF THE ILLINOIS...IROQUOIS...VERMILLION AND KANKAKEE
RIVERS...AND SUGAR CREEK WILL REMAIN IN FLOOD.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED THROUGH TONIGHT.

&&

LMZ740>745-142145-
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-
437 PM CDT MON JUL 13 2015

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

.DAY ONE...TONIGHT.

THUNDERSTORMS PRODUCING WIND GUSTS IN EXCESS OF 50 KT...LARGE
HAIL AND FREQUENT LIGHTNING ARE POSSIBLE THIS EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

CONDITIONS HAZARDOUS FOR SMALL CRAFT ARE LIKELY TUESDAY NIGHT.

THERE IS A CHANCE FOR THUNDERSTORMS ON TUESDAY AND THEN A
PERIODIC CHANCE OF THUNDERSTORMS THURSDAY THROUGH SUNDAY.

&&

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-142145-
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-
437 PM CDT MON JUL 13 2015

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

.DAY ONE...TONIGHT.

THUNDERSTORMS PRODUCING WIND GUSTS IN EXCESS OF 50 KT...LARGE
HAIL AND FREQUENT LIGHTNING ARE POSSIBLE THIS EVENING FOR THE
SOUTHERN PORTIONS OF THE LAKE.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THERE IS A CHANCE OF THUNDERSTORMS ON TUESDAY AND THEN A PERIODIC
CHANCE FOR THUNDERSTORMS THURSDAY THROUGH SUNDAY.

&&

RODRIGUEZ

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

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

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 7:57 PM CDTAreal Flood WarningLOTFord, Iroquois, Livingston18 hr
Jul 12, 8:39 PM CDTRiver Flood WarningLOTGrundy, Will3 days
Jul 13, 4:18 AM CDTHeat AdvisoryLOTFord, Grundy, Iroquois, Kankakee, LaSalle, Lee and 1 more15 hr
Jul 13, 4:34 AM CDTSpecial Marine WarningLOT116 min
Jul 13, 5:05 AM CDTSevere Thunderstorm WarningLOTBoone, McHenry, Winnebago55 min
Jul 13, 5:37 AM CDTSevere Thunderstorm WarningLOTLake38 min
Jul 13, 5:41 AM CDTSevere Thunderstorm WarningLOTBoone, Cook, DeKalb, DuPage, Kane, Lake and 3 more64 min
Jul 13, 6:05 AM CDTSpecial Marine WarningLOT115 min
Jul 13, 6:08 AM CDTSpecial Weather StatementLOTLee52 min
Jul 13, 6:22 AM CDTSevere Thunderstorm WarningLOTCook, DeKalb, DuPage, Kane, Kendall, Will53 min
Jul 13, 6:28 AM CDTAreal Flood AdvisoryLOTBoone, Cook, DeKalb, DuPage, Kane, Lake and 4 more4 hr
Jul 13, 6:55 AM CDTSpecial Weather StatementLOTKendall, Will50 min
Jul 13, 7:19 AM CDTSpecial Weather StatementLOTGrundy, Kankakee41 min
Jul 13, 7:47 AM CDTSpecial Weather StatementLOTKankakee43 min
Jul 13, 7:55 AM CDTAreal Flood AdvisoryLOTCook, DeKalb, Ford, Grundy, Iroquois, Kankakee and 5 more6 hr
Jul 13, 8:17 AM CDTSevere Thunderstorm WarningLOTFord, Livingston43 min
Jul 13, 8:46 AM CDTSpecial Weather StatementLOTFord, Iroquois59 min
Jul 13, 9:53 AM CDTRiver Flood AdvisoryLOTKankakee4 days
Jul 13, 12:07 PM CDTRiver Flood WarningLOTGrundy67 hr
Jul 13, 12:07 PM CDTRiver Flood WarningLOTLaSalle3 days
Jul 13, 1:09 PM CDTAreal Flood WarningLOTFord, Iroquois, Livingston6 hr
Jul 13, 5:37 PM CDTSevere Thunderstorm WarningLOTGrundy, LaSalle, Livingston53 min
Jul 13, 6:03 PM CDTAreal Flood AdvisoryLOTGrundy, LaSalle4 hr
Jul 13, 6:29 PM CDTSevere Thunderstorm WarningLOTFord, Grundy, Kankakee, Livingston61 min
Jul 13, 6:38 PM CDTSevere Thunderstorm WarningLOTGrundy, Kendall, Will52 min
Jul 13, 6:40 PM CDTSevere Thunderstorm WarningLOTIroquois35 min
Jul 13, 9:28 AM CDTRiver Flood WarningLOTJasper4 days

Nearby

Severe Thunderstorm Warnings in Illinois, 2015Every severe thunderstorm warning in 2015

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.