Alert archive / Illinois / Severe Thunderstorm Warnings in 2005

Severe Thunderstorm Warning 92, NWS Chicago, IL

July 25, 2005Grundy County, LaSalle County, Livingston County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 25, 2005, 11:45 PM CDT for Grundy County, LaSalle County, Livingston County, Illinois. It was in force for 41 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 25, 2005, 11:45 PM CDT (04:45 UTC)
Expired: Jul 26, 2005, 12:26 AM CDT
In force: 41 min
Issued by: NWS Chicago, IL
Area: Counties, with a storm outline in the text

Counties Grundy County, IL, LaSalle County, IL, Livingston County, IL

The radar

The Chicago radar (KLOT), 66 km from the middle of the area, began a volume at 04:47 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

Lincoln, IL (KILX), launched 00:00Z, 4.8 hours before the alert went out and 114 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: 2558 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 1613 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 179 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 13.6

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 25, 7:10 PM CDT, 4 hours 35 minutes earlier.

Area forecast discussion, Jul 25, 7:10 PM CDT, 4 hours 35 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
710 PM CDT MON JUL 25 2005

.DISCUSSION FOR AFTERNOON GRIDS...
WEAK SURFACE BOUNDARY LAYING ACROSS NORHTERN ILLINOIS THIS MORNING
APPEARS TO HAVE SERVED AS FOCUS FOR MORNING/EARLY AFTERNOON
THUNDERSTORM DEVELOPMENT. GIVEN TIME OF DAY OF DEVELOPMENT AND RICH
ENVIRONMENT FEAR WAS THAT STORMS WOULD CONTINUE TO DEVELOP WITH MANY
OF THEM BECOMING SEVERE. THOUGH 88D DATA INDICATED HIGH VIL AND SOME
ROTATION, REPORTS OF SEVERE WEATHER DID NOT COME IN WITH EXCEPTION
OF HEAVY RAIN. AT THIS TIME BOUNDARY HAS MOVED NORTH INTO NORTHERN
WISCONSIN WITH BEST DEVELOPMENT APPEARING NORTH OF IL/WI STATE LINE.
ADDITIONAL THUNDERSTORMS ARE STILL POSSIBLE SOUTH OF BOUNDARY ACROSS
FORECAST AREA AND COULD BE AIDED BY REMAINING DIURNAL HEATING AS
CLOUD COVER THINS/CLEARS IN WAKE OF PREVIOUS STORMS.

OVER LONGER HAUL CHARACTER OF H5 FLOW CHANGES WITH SHORT WAVE MOVES
EAST THROUGH FLOW ACROSS AREA TONIGHT AND TUESDAY. WAVES SHOULD
PROVIDE FORCING IN AREA OF GOOD MOSITURE WITH SHOWERS AND
THUNDERSTORMS POSSIBLE TONIGHT AND LIKELY TUESDAY. AT SURFACE EXPECT
COLD FRONT TO PASS ACROSS AREA EARLY TUESDAY. SECOND WAVE CAUSES
FLOW TO GO NORTHWEST AND BRING FIRST REAL CHANGE IN WX/TEMPS IN
QUITE A WHILE.

MOST SIG CHANGE FOR LATER PORTION OF THIS CYCLE WILL BE TO TEMPS.
MAX SHOULD SETTLE CLOSER TO SEASONAL NORMS IN THE UPPER 70S AND
LOWER 80S. GIVEN THE 15 TO 20 DEGREE DROP FROM PAST SEVERAL/MANY
DAYS, SHOULD BE A WELCOME RELIEF. MINS ALSO DROP TO COOL LOWER 60S.
AFTER PERCIP TONIGHT/TUESDAY, REMAINDER OF CYCLE WILL BE DRY.

&&

.AVIATION DISCUSSION FOR 00Z TAFS:
MOIST AIRMASS CONTINUING TO SPROUT TSTMS THIS EVENING...ALTHO LOW
LVL JET EXPECTED TO DEVELOP VERY LT TNGT AND PROVIDE BETTER DYNAMICS
THAT WUD OVERCOME LACK OF SOLAR ENERGY. WITH SFC WARMING CAPES OVR
3K THIS EVENING...LOWERING OVERNIGHT. SHORT WAVE PROVIDING LIFT THIS
EVE SHUD BE TO LK MICH BY MDNGT...SO SHUD SEE LULL BY THEN IF NOT
BFR. NEXT MAJOR WAVE WILL ACCOMPANY SFC COLD FNT NOW FIRING TSTM
LINE FROM WI THRU NRN KS. THIS SHUD BE HERE AFT SUNUP AND WHIP THRU
BFR NOON. FNT STALLS A BIT AT MIDDAY AS SECONDARY WAVE RIDES UP
FRONT FROM MO. THUS SHUD HAVE SECONDARY SHOT OF STORMS IN LT AFTN.

GENERALLY GOING WITH VFR CIGS AND VSBY XCP IN TSTMS WITH SOUTH WIND
VEERING TO SW AS WARM FNT MOVES NORTH OF TERMINALS THIS EVE. WINDS
TURNING NORTH WITH COLD FRONT IN MORNING. AFTN CONVECTION SHUD BE
ELEVATED AND OVERRIDING COLD FRONT. AFTER THIS SECONDARY WAVE PASSES
TO EAST TUES EVENING...CAN EXPECT COLD SNAP WITH DEWPTS DROPPING TO
50S NEXT DAY AND HIGHS ONLY IN 70S.

&&

.WATCHES/WARNINGS/ADVISORIES...
.IL...HEAT ADVISORY LASALLE LIVINGSTON FORD AND IROQUOIS THRU 9 PM.
.IN...HEAT ADVISORY BENTON THRU 9PM.
.LK MI...NONE.

Hazardous weather outlook, Jul 25, 10:45 PM CDT, 1 hour 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>

In the hours before

Local storm report, Jul 25, 8:33 PM CDT, 3 hours 12 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, Jul 25, 10:39 PM CDT, 1 hour 6 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>

Special weather statement, Jul 25, 11:31 PM CDT, 14 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.

Issued	Product	Office	Counties	Lasted
Jul 25, 7:35 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Lake	40 min
Jul 25, 7:55 PM CDT	Special Marine Warning	LOT		95 min
Jul 25, 8:15 PM CDT	Severe Thunderstorm Warning	LOT	Cook	24 min
Jul 26, 4:16 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle, Livingston	44 min
Jul 26, 4:44 PM CDT	Tornado Warning	LOT	LaSalle, Livingston	26 min
Jul 26, 5:06 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle, Livingston	34 min
Jul 26, 5:58 PM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois, Livingston	47 min
Jul 26, 6:08 PM CDT	Tornado Warning	LOT	Ford, Iroquois, Livingston	50 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2005 Every severe thunderstorm warning in 2005

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.