Alert archive / Illinois / Tornado Warnings in 2010

Tornado Warning 19, NWS Chicago, IL

June 21, 2010Lake County, McHenry County, Illinois

NWS Chicago, IL issued this tornado warning at Jun 21, 2010, 10:22 PM CDT for Lake County, McHenry County, Illinois. It was in force for 38 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 21, 2010, 10:22 PM CDT (03:22 UTC)
Expired
Jun 21, 2010, 11:00 PM CDT
In force
38 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon

Counties Lake County, IL, McHenry County, IL

The radar

The Milwaukee radar (KMKX), 77 km from the middle of the area, began a volume at 03:25 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 00:00Z, 3.4 hours before the alert went out and 209 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, Davenport, at 00:00Z on 2010-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2621 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2010-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 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
2621 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
930 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
154 m²/s²
Significant tornado parameter
1.5
Supercell composite
7.6

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Jun 21, 9:23 PM CDT, 59 minutes earlier.

Area forecast discussion, Jun 21, 9:23 PM CDT, 59 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Hazardous weather outlook, Jun 21, 4:56 PM CDT, 5 hours 26 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
456 PM CDT MON JUN 21 2010

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
222200-
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-
456 PM CDT MON JUN 21 2010 /556 PM EDT MON JUN 21 2010/

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

.DAY ONE...TONIGHT.

  WEATHER HAZARDS EXPECTED:

  SCATTERED THUNDERSTORMS...SOME COULD PRODUCE:
    DAMAGING WINDS IN EXCESS OF 70 MPH.
    HAIL TO THE SIZE OF GOLFBALLS.
    VERY HEAVY RAINFALL WITH LOCALIZED FLOODING.
    FREQUENT CLOUD TO GROUND LIGHTNING.
    POSSIBLY A TORNADO.

  AREAS AFFECTED AND TIMING:

  SCATTERED THUNDERSTORMS WILL DEVELOP EARLY THIS EVENING AND
  COULD LINGER INTO THE EARLY PORTIONS OF THE OVERNIGHT
  HOURS...WITH THE GREATEST POTENTIAL FOR SEVERE WEATHER SOUTH OF
  A VALPARAISO TO JOLIET TO OREGON LINE.

  DISCUSSION:

  THE ATMOSPHERE IS QUICKLY DESTABILIZING AND WINDS ALOFT ARE
  INCREASING IN ADVANCE OF AN APPROACHING UPPER LEVEL
  DISTURBANCE...SETTING THE STAGE FOR THE DEVELOPING THUNDERSTORMS
  TO QUICKLY BECOME SEVERE. GIVEN THE VERY STRONG INSTABILITY AND
  INCREASING WINDS ALOFT THE POTENTIAL EXISTS FOR THE MOST INTENSE
  STORMS TO PRODUCE DAMAGING WINDS...LARGE HAIL AND POSSIBLY A
  TORNADO.

  THE THREAT OF SEVERE THUNDERSTORMS SHOULD GRADUALLY DIMINISH
  LATER THIS EVENING INTO THE OVERNIGHT HOURS. GIVEN THE VERY
  MOIST AIRMASS IN PLACE THE POTENTIAL WILL EXIST FOR LOCALLY
  HEAVY RAINFALL...WHICH COULD RESULT IN LOCALIZED FLASH FLOODING.

  FINALLY...PORTIONS OF THE UPPER ILLINOIS RIVER AND SUGAR CREEK
  WILL REMAIN IN FLOOD.

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

  THE AREA WILL CONTINUE TO SEE PERIODIC THUNDERSTORMS TUESDAY
  THROUGH WEDNESDAY NIGHT. WE WILL REMAIN IN A PATTERN THAT IS
  CONDUCIVE FOR SOME OF THESE THUNDERSTORMS TO BE SEVERE WITH
  DAMAGING WINDS THE PRIMARY THREAT.

  THE THUNDERSTORMS WILL ALSO PRODUCE LOCALLY VERY HEAVY RAINFALL
  TOTALS...WITH THE THREAT OF FLASH FLOODING INCREASING WITH EACH
  SUCCESSIVE ROUND OF THUNDERSTORMS. GIVEN THE POTENTIAL FOR
  REPEATED BOUTS OF HEAVY RAINFALL...THE THREAT DOES EXIST FOR
  SIGNIFICANT FLOODING PROBLEMS TO DEVELOP THIS WEEK.

  PORTIONS OF THE UPPER ILLINOIS RIVER WILL REMAIN IN FLOOD
  THROUGH THE UPCOMING WORK WEEK.

  HEAT INDICES OVER 100 DEGREES ARE POSSIBLE OVER THE WEEKEND.

  THERE IS ALSO A CHANCE OF THUNDERSTORMS BY SATURDAY NIGHT INTO
  SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS WILL BE NEEDED THIS EVENING.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

LMZ740>745-222200-
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-
456 PM CDT MON JUN 21 2010

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

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS.

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

PERIODIC CHANCES OF THUNDERSTORMS WILL CONTINUE TUESDAY THROUGH
WEDNESDAY NIGHT. SOME OF THE STORMS MAY BE SEVERE WITH WIND GUSTS
OVER 50 KNOTS THE PRIMARY HAZARD.

THERE IS ANOTHER CHANCE OF THUNDERSTORMS SATURDAY NIGHT INTO
SUNDAY.

&&

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-
870-872-874-876-878-222200-
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 TOW 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-
456 PM CDT MON JUN 21 2010

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

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS.

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

THERE WILL BE PERIODIC CHANCES OF THUNDERSTORMS TUESDAY THROUGH
WEDNESDAY NIGHT. SOME OF THE STORMS MAY BE SEVERE ACROSS SOUTHERN
LAKE MICHIGAN...WITH WIND GUSTS OVER 50 KNOTS THE PRIMARY HAZARD.

THERE IS ALSO A CHANCE OF THUNDERSTORMS OVER MAINLY NORTHERN
PORTIONS OF THE LAKE BY FRIDAY NIGHT INTO SATURDAY...SPREADING TO
SOUTHERN PORTIONS OF THE LAKE SATURDAY.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO

IZZI

In the hours before

Local storm report, Jun 21, 8:58 PM CDT, 1 hour 24 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
858 PM CDT MON JUN 21 2010

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

0853 PM     HEAVY RAIN       WINNEBAGO               42.27N 89.24W
06/21/2010  U0.00 INCH       WINNEBAGO          IL   AMATEUR RADIO

            RAIN IN EXCESS OF ONE INCH PER HOUR.

&&

ALYZA
Local storm report, Jun 21, 9:13 PM CDT, 1 hour 9 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
913 PM CDT MON JUN 21 2010

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

0905 PM     TSTM WND DMG     ROCKFORD                42.27N 89.06W
06/21/2010                   WINNEBAGO          IL   LAW ENFORCEMENT

            MEDIUM SIZED TREE LIMB DOWN ON RT. 173

&&

ALYZA
Local storm report, Jun 21, 9:18 PM CDT, 1 hour 4 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
918 PM CDT MON JUN 21 2010

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

0600 PM     FUNNEL CLOUD     CISSNA PARK             40.57N 87.89W
06/21/2010                   IROQUOIS           IL   EMERGENCY MNGR

            FUNNEL CLOUD MOVING TOWARD WELLINGTON. POSSIBLE
            TOUCHDOWN.

&&

ALYZA
Local storm report, Jun 21, 9:34 PM CDT, 48 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Local storm report, Jun 21, 10:13 PM CDT, 9 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Local storm report, Jun 21, 10:22 PM CDT, 0 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 7:18 PM CDTSevere Thunderstorm WarningLOTIroquois57 min
Jun 21, 7:45 PM CDTSpecial Weather StatementLOTOgle45 min
Jun 21, 7:47 PM CDTFlash Flood WarningLOTFord, Iroquois6 hr
Jun 21, 7:59 PM CDTSevere Thunderstorm WarningLOTOgle, Winnebago31 min
Jun 21, 8:34 PM CDTSevere Thunderstorm WarningLOTBoone, Ogle, Winnebago56 min
Jun 21, 8:51 PM CDTSevere Thunderstorm WarningLOTFord, Grundy, Kankakee, LaSalle, Livingston, Will54 min
Jun 21, 9:17 PM CDTTornado WarningLOTFord, Iroquois, Livingston43 min
Jun 21, 9:25 PM CDTRiver Flood AdvisoryLOTGrundy, Will4 days
Jun 21, 9:34 PM CDTSevere Thunderstorm WarningLOTBoone, McHenry56 min
Jun 21, 9:50 PM CDTSevere Thunderstorm WarningLOTCook, Grundy, Kendall, Will32 min
Jun 21, 9:53 PM CDTSpecial Marine WarningLOT112 min
Jun 21, 9:54 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois66 min
Jun 21, 10:06 PM CDTSpecial Marine WarningLOT114 min
Jun 21, 10:10 PM CDTSevere Thunderstorm WarningLOTIroquois, Kankakee65 min
Jun 21, 10:15 PM CDTRiver Flood AdvisoryLOTGrundy55 hr
Jun 21, 10:15 PM CDTRiver Flood AdvisoryLOTLaSalle55 hr
Jun 21, 10:52 PM CDTSevere Thunderstorm WarningLOTLake24 min
Jun 21, 10:58 PM CDTSevere Thunderstorm WarningLOTCook, Lake47 min
Jun 21, 11:05 PM CDTSpecial Marine WarningLOT70 min
Jun 22, 12:00 AM CDTSevere Thunderstorm WarningLOTFord, Iroquois45 min
Jun 22, 12:35 AM CDTSevere Thunderstorm WarningLOTIroquois40 min
Jun 22, 1:49 AM CDTAreal Flood AdvisoryLOTFord, Iroquois3 hr
Jun 22, 4:52 AM CDTFlash Flood WarningLOTIroquois6 hr
Jun 22, 2:57 PM CDTRiver Flood AdvisoryLOTIroquois, Kankakee3 days
Jun 21, 8:46 PM CDTRiver Flood WarningLOTLake, Newton13 hr
Jun 22, 10:50 AM CDTFlash Flood WarningLOTBenton3 hr
Jun 22, 1:43 PM CDTAreal Flood WarningLOTBenton17 hr

Nearby

Tornado Warnings in Illinois, 2010Every tornado warning in 2010Tornadoes in 2010

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.