Alert archive / Illinois / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 78, NWS Chicago, IL

July 23, 2016Cook County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 23, 2016, 6:13 PM CDT for Cook County, Illinois. It was in force for 47 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, 2016, 6:13 PM CDT (23:13 UTC)
Expired: Jul 23, 2016, 7:00 PM CDT
In force: 47 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Cook County, IL

The radar

The Chicago radar (KLOT), 49 km from the middle of the area, began a volume at 23:17 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
Jul 23, 3:23 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.2 hours before the alert went out and 239 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: 2607 J/kg
Mixed-layer CIN: -89 J/kg
Mixed-layer LCL: 807 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 83 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 Jul 23, 6:06 PM CDT, 7 minutes earlier.

Area forecast discussion, Jul 23, 6:06 PM CDT, 7 minutes before

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Hazardous weather outlook, Jul 23, 4:06 PM CDT, 2 hours 7 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
406 PM CDT SAT JUL 23 2016

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
242115-
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-
406 PM CDT SAT JUL 23 2016 /506 PM EDT SAT JUL 23 2016/

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

.DAY ONE...TONIGHT.

WEATHER HAZARDS EXPECTED:
  SIGNIFICANT THUNDERSTORM RISK...WITH AN ASSOCIATED:
      LIMITED HAIL RISK...UP TO HALF DOLLAR SIZE.
      ELEVATED THUNDERSTORM WIND DAMAGE RISK...UP TO 70 MPH.
  LIMITED FLOODING RISK.
  SIGNIFICANT EXCESSIVE HEAT RISK.

DISCUSSION:

ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON
MAINLY ALONG AND NORTH OF INTERSTATE 80. MOST STORMS WILL BE SLOW
MOVING AND THUS CAPABLE OF HEAVY RAINFALL AND LOCALIZED FLOODING.
IN ADDITION...THERE WILL BE A BRIEF GUSTY WIND THREAT WITH ANY STORMS.

A MORE ORGANIZED AREA OF THUNDERSTORMS WILL MOVE IN FROM EASTERN IOWA
THIS EVENING AND IMPACT AREAS ALONG AND NORTH OF INTERSTATE 80. DAMAGING
WINDS...TORRENTIAL DOWNPOURS AND LIGHTNING WILL BE THE MAIN THREATS. A
MINIMAL TORNADO THREAT EXISTS NEAR THE WISCONSIN BORDER.

ADDITIONAL THUNDERSTORMS ARE POSSIBLE OVERNIGHT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

SUNDAY...
  LIMITED FLOODING RISK.
  LIMITED SEVERE THUNDERSTORM RISK.
  SIGNIFICANT EXCESSIVE HEAT RISK.
MONDAY...
  LIMITED THUNDERSTORM RISK.
WEDNESDAY THROUGH FRIDAY...
  LIMITED THUNDERSTORM RISK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER REPORTS WILL LIKELY BE NEEDED THROUGH TONIGHT.

GENERAL STORM MOTION OF THE DAY:

MOVING TOWARD THE EAST AT 10 MPH THIS AFTERNOON AND THEN TO THE SOUTHEAST
AT 20 TO 30 MPH THIS EVENING AND TONIGHT.

&&

LMZ740>745-242115-
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-
406 PM CDT SAT JUL 23 2016

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

.DAY ONE...TONIGHT.

ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH LATE AFTERNOON WITH MORE
ORGANIZED THUNDERSTORMS EXPECTED THIS EVENING. ADDITIONAL STORMS ARE POSSIBLE
OVERNIGHT. STORMS MAY PRODUCE WIND GUSTS IN EXCESS OF 34 KT...WITH ISOLATED
STORMS PRODUCING GUSTS IN EXCESS OF 50 KT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THERE ARE PERIODIC CHANCES FOR THUNDERSTORMS SUNDAY...AND AGAIN
WEDNESDAY THROUGH FRIDAY.

&&

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-242115-
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-
406 PM CDT SAT JUL 23 2016

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

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS LATE THIS AFTERNOON WITH
THUNDERSTORMS THIS EVENING AND OVERNIGHT. STORMS MAY PRODUCE WIND
GUSTS IN EXCESS OF 34 KT...WITH ISOLATED STORMS PRODUCING GUSTS IN EXCESS
OF 50 KT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THERE IS A CHANCE OF THUNDERSTORMS SUNDAY...AND THEN AGAIN
TUESDAY NIGHT THROUGH FRIDAY.

&&

MDB

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

In the hours before

Local storm report, Jul 23, 5:06 PM CDT, 1 hour 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
506 PM CDT SAT JUL 23 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0503 PM     HAIL             ROCKFORD                42.27N 89.06W
07/23/2016  E0.25 INCH       WINNEBAGO          IL   PUBLIC

            PEA SIZE HAIL AT HARRISON AND ALPINE ROADS.

&&

Local storm report, Jul 23, 5:22 PM CDT, 51 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
522 PM CDT SAT JUL 23 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0450 PM     HAIL             BELVIDERE               42.25N 88.85W
07/23/2016  E0.25 INCH       BOONE              IL   TRAINED SPOTTER

            VERY HEAVY RAINFALL...VISIBILITY AROUND 1/2 MILE. LOTS OF
            CLOUD TO GROUND LIGHTNING.

&&

RATZER

Local storm report, Jul 23, 5:34 PM CDT, 39 minutes before

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Local storm report, Jul 23, 5:40 PM CDT, 33 minutes before

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Special weather statement, Jul 23, 5:44 PM CDT, 29 minutes before

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Local storm report, Jul 23, 5:48 PM CDT, 25 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
Jul 23, 3:22 PM CDT	Special Weather Statement	LOT	Boone	23 min
Jul 23, 3:48 PM CDT	Special Weather Statement	LOT	Boone	27 min
Jul 23, 3:55 PM CDT	Areal Flood Advisory	LOT	Boone, McHenry, Winnebago	3 hr
Jul 23, 4:13 PM CDT	Severe Thunderstorm Warning	LOT	Boone, McHenry	47 min
Jul 23, 4:58 PM CDT	Severe Thunderstorm Warning	LOT	Boone, DeKalb, McHenry	47 min
Jul 23, 5:00 PM CDT	Flash Flood Warning	LOT	Boone, McHenry, Winnebago	6 hr
Jul 23, 5:25 PM CDT	Severe Thunderstorm Warning	LOT	Boone, Winnebago	35 min
Jul 23, 5:28 PM CDT	Severe Thunderstorm Warning	LOT	Kane, McHenry	47 min
Jul 23, 5:29 PM CDT	Special Marine Warning	LOT		61 min
Jul 23, 5:44 PM CDT	Areal Flood Advisory	LOT	Lake, McHenry	5 hr
Jul 23, 5:44 PM CDT	Special Weather Statement	LOT	Lake	46 min
Jul 23, 5:51 PM CDT	Special Marine Warning	LOT		84 min
Jul 23, 6:11 PM CDT	Special Marine Warning	LOT		94 min
Jul 23, 6:30 PM CDT	Special Marine Warning	LOT		90 min
Jul 23, 6:50 PM CDT	Areal Flood Advisory	LOT	Cook, DuPage	10 hr

Nearby

Severe Thunderstorm Warnings in Illinois, 2016 Every severe thunderstorm warning in 2016

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.