Alert archive / Illinois / Severe Thunderstorm Warnings in 2014

Severe Thunderstorm Warning 57, NWS Chicago, IL

June 17, 2014Boone County, Winnebago County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jun 17, 2014, 4:39 AM CDT for Boone County, Winnebago County, Illinois. It was in force for 36 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: Jun 17, 2014, 4:39 AM CDT (09:39 UTC)
Expired: Jun 17, 2014, 5:15 AM CDT
In force: 36 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Boone County, IL, Winnebago County, IL

The radar

The Milwaukee radar (KMKX), 80 km from the middle of the area, began a volume at 09:43 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
Jun 17, 4:11 AM CDT	Tornado Watch	SPC	3 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 9.7 hours before the alert went out and 148 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: 2074 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 1135 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 122 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 5.2

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 Jun 17, 4:15 AM CDT, 24 minutes earlier.

Area forecast discussion, Jun 17, 4:15 AM CDT, 24 minutes before

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Hazardous weather outlook, Jun 16, 4:14 PM CDT, 12 hours 25 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
414 PM CDT MON JUN 16 2014

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
172115-
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-
414 PM CDT MON JUN 16 2014 /514 PM EDT MON JUN 16 2014/

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

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

    THUNDERSTORMS WHICH MAY PRODUCE:
    DAMAGING WINDS.
    HEAVY RAINFALL AND LOCALIZED FLASH FLOODING.
    HAIL TO THE SIZE OF QUARTERS.
    FREQUENT LIGHTNING.

  AREAS AFFECTED AND TIMING:

  SCATTERED THUNDERSTORMS ARE POSSIBLE ACROSS NORTH CENTRAL
  ILLINOIS THROUGH SUNSET...WITH CHANCES INCHING EASTWARD THROUGH
  LATE EVENING. THERE IS A SMALL CHANCE FOR FEW OF THESE TO
  BECOME SEVERE...WITH POSSIBLE HAIL AND GUSTY WINDS. MORE
  WIDESPREAD THUNDERSTORM COVERAGE IS LIKELY ALONG AND NORTH OF
  INTERSTATE 80 OVERNIGHT. THESE STORMS WILL HAVE THE HIGHEST
  CHANCES OF PRODUCING DAMAGING WIND GUSTS AND HEAVY RAINFALL.

  DISCUSSION:

  AS RICH MOISTURE CONTINUES TO RETURN OVER THE AREA THIS
  EVENING...SCATTERED THUNDERSTORMS ACROSS NORTHWEST ILLINOIS MAY
  EVOLVE INTO NORTH CENTRAL ILLINOIS. DUE TO A HIGH AMOUNT OF
  INSTABILITY...THESE STORMS COULD BECOME SEVERE. MEANWHILE...A
  SEVERE COMPLEX OF THUNDERSTORMS IS VERY LIKELY TO DEVELOP OVER
  MINNESOTA AND NORTHERN IOWA. THIS THUNDERSTORM ACTIVITY WILL
  SPREAD SOUTHEASTWARD ACROSS NORTHEAST IOWA AND SOUTHERN
  WISCONSIN AND LIKELY INTO NORTHERN ILLINOIS OVERNIGHT. AS IS
  COMMON WITH ORGANIZED THUNDERSTORM COMPLEXES...DAMAGING WINDS
  AND HEAVY RAIN WOULD BE THE MOST LIKELY THREATS...THOUGH LARGE
  HAIL WILL BE POSSIBLE.

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

SOME THUNDERSTORMS ARE LIKELY TO BE ONGOING ACROSS THE AREA EARLY
TUESDAY MORNING WHICH MAY BE CAPABLE OF STRONG WINDS AND HEAVY
RAINFALL.

THERE WILL BE PERIODIC CHANCES FOR THUNDERSTORMS TUESDAY AFTERNOON
THROUGH SATURDAY.

EARLY SEASON HEAT INDICES AROUND 100 DEGREES ARE POSSIBLE TUESDAY
AFTERNOON...ESPECIALLY SOUTH OF INTERSTATE 80.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATER THIS EVENING INTO OVERNIGHT.

&&

LMZ740>745-172115-
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-
414 PM CDT MON JUN 16 2014

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 ARE POSSIBLE LATER THIS EVENING THROUGH OVERNIGHT.
WIND GUSTS IN EXCESS OF 45 KT ARE POSSIBLE.

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

WINDS HAZARDOUS TO SMALL CRAFT ARE POSSIBLE ON TUESDAY.

THERE WILL BE PERIODIC CHANCES FOR THUNDERSTORMS TUESDAY THROUGH
SATURDAY.

&&

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-172115-
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-
414 PM CDT MON JUN 16 2014

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

.DAY ONE...TONIGHT.

THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF LAKE MICHIGAN
OVERNIGHT. SOME OF THESE THUNDERSTORMS COULD PRODUCE WINDS IN
EXCESS OF 50 KT.

AREAS OF FOG...SOME OF WHICH MAY BE DENSE...ARE LIKELY.

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

THERE WILL BE PERIODIC CHANCES FOR THUNDERSTORMS TUESDAY
THROUGH SUNDAY.

AREAS OF FOG...SOME OF WHICH MAY BE DENSE...ARE LIKELY TUESDAY AND
TUESDAY NIGHT.

&&

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

Special weather statement, Jun 17, 12:47 AM CDT, 3 hours 52 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1247 AM CDT TUE JUN 17 2014

ILZ003-170630-
WINNEBAGO IL-
1247 AM CDT TUE JUN 17 2014

...SPECIAL WEATHER STATEMENT...

AT 1244 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 11 MILES NORTHWEST
OF SOUTH BELOIT TO 12 MILES SOUTHWEST OF PECATONICA...MOVING EAST AT
30 MPH.

CITIES AND TOWNS AFFECTED...
  DURAND...             LAKE SUMMERSET...     PECATONICA...
  ROCKTON...            SOUTH BELOIT...       WINNEBAGO...
  ROSCOE...             MACHESNEY PARK...     LOVES PARK...
  ROCKFORD...

OTHER LOCATIONS AFFECTED...
ROCK CUT STATE PARK...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE
OBJECTS TO BLOW AROUND. 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 THESE
STORMS HAVE PASSED.

&&

LAT...LON 4250 8894 4215 8894 4215 8917 4220 8917
      4220 8940 4250 8940
TIME...MOT...LOC 0545Z 278DEG 26KT 4259 8918 4222 8955

Special weather statement, Jun 17, 1:21 AM CDT, 3 hours 18 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
121 AM CDT TUE JUN 17 2014

ILZ004-005-170700-
BOONE IL-MCHENRY IL-
121 AM CDT TUE JUN 17 2014

...SPECIAL WEATHER STATEMENT...

AT 118 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 9 MILES NORTHWEST OF
CAPRON TO ROCKFORD...MOVING EAST AT 40 MPH.

CITIES AND TOWNS AFFECTED...
  POPLAR GROVE...       BELVIDERE...          CAPRON...
  HARVARD...            MARENGO...            HEBRON...
  WOODSTOCK...          RICHMOND...           WONDER LAKE...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE
OBJECTS TO BLOW AROUND. 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 THESE
STORMS HAVE PASSED.

&&

LAT...LON 4250 8826 4231 8839 4216 8871 4215 8894
      4250 8894
TIME...MOT...LOC 0620Z 261DEG 36KT 4253 8879 4226 8897

Special weather statement, Jun 17, 2:00 AM CDT, 2 hours 39 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
Jun 17, 12:47 AM CDT	Special Weather Statement	LOT	Winnebago	43 min
Jun 17, 1:21 AM CDT	Special Weather Statement	LOT	Boone, McHenry	39 min
Jun 17, 2:00 AM CDT	Special Weather Statement	LOT	McHenry	45 min
Jun 17, 2:04 AM CDT	Special Marine Warning	LOT		86 min
Jun 17, 4:51 AM CDT	Special Weather Statement	LOT	Boone	24 min
Jun 17, 5:07 AM CDT	Special Weather Statement	LOT	McHenry	38 min
Jun 17, 6:17 AM CDT	Small Craft Advisory	LOT		7 hr
Jun 17, 10:10 AM CDT	River Flood Warning	LOT	Lake	6 days

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.