Alert archive / Illinois / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 21, NWS Chicago, IL

May 15, 2007Grundy County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at May 15, 2007, 1:36 PM CDT for Grundy County, Illinois. It was in force for 39 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 15, 2007, 1:36 PM CDT (18:36 UTC)
Expired
May 15, 2007, 2:15 PM CDT
In force
39 min
Issued by
NWS Chicago, IL
Area
Counties, with a storm outline in the text

County Grundy County, IL

The radar

The Chicago radar (KLOT), 51 km from the middle of the area, began a volume at 18:38 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.

What was reported inside it

TimeReportWhereRemark
May 15, 1:43 PM CDTHAIL 0.88Coal City, ILNICKEL SIZE HAIL REPORTED IN COAL CITY

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 6.6 hours before the alert went out and 122 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 2007-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 20 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 2007-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 square meters per square second.193958Sfc1 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
20 J/kg
Mixed-layer CIN
-273 J/kg
Mixed-layer LCL
1998 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS53 KLOT 151837
SVRLOT
ILC063-151915-
/O.NEW.KLOT.SV.W.0021.070515T1836Z-070515T1915Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
136 PM CDT TUE MAY 15 2007

THE NATIONAL WEATHER SERVICE IN ROMEOVILLE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  GRUNDY COUNTY IN NORTHEAST ILLINOIS...

* UNTIL 215 PM CDT

* AT 134 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
  THUNDERSTORM 8 MILES SOUTHWEST OF MAZON...AND MOVING NORTHEAST AT
  35 MPH. THIS STORM IS CAPABLE OF PRODUCING PENNY SIZE HAIL.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  MAZON BY 145 PM...
  BRACEVILLE BY 155 PM...
  COAL CITY BY 200 PM...

MOVE INDOORS AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

LAT...LON 4127 8859 4113 8858 4113 8846 4122 8826
      4143 8827

$$

WILSON
2 follow-up statements
000 
WWUS53 KLOT 151859
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
159 PM CDT TUE MAY 15 2007

ILC063-151915-
/O.CON.KLOT.SV.W.0021.000000T0000Z-070515T1915Z/
GRUNDY IL-
159 PM CDT TUE MAY 15 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM CDT
FOR GRUNDY COUNTY...

AT 155 PM CDT...THE PUBLIC REPORTED A SEVERE THUNDERSTORM CAPABLE OF
PRODUCING PENNY SIZE HAIL. NEAR BRACEVILLE..MOVING NORTHEAST AT 40
MPH.

THIS IS A DANGEROUS STORM. SEEK SHELTER INSIDE A STURDY BUILDING AND
STAY AWAY FROM WINDOWS

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF
YOUR HOME OR BUSINESS. THIS STORM HAS THE POTENTIAL TO CAUSE SERIOUS
INJURY AND SIGNIFICANT DAMAGE TO PROPERTY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM TUESDAY
EVENING FOR NORTHEASTERN ILLINOIS.

LAT...LON 4127 8859 4113 8858 4113 8846 4122 8826
      4143 8827

$$

WILSON
000 
WWUS53 KLOT 151915
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
215 PM CDT TUE MAY 15 2007

ILC063-151925-
/O.EXP.KLOT.SV.W.0021.000000T0000Z-070515T1915Z/
GRUNDY IL-
215 PM CDT TUE MAY 15 2007

...THE SEVERE THUNDERSTORM WARNING FOR GRUNDY COUNTY EXPIRES AT 215
PM CDT...

THE SEVERE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND 
MOVED OUT OF THE WARNED AREA.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM TUESDAY
EVENING FOR NORTHEASTERN ILLINOIS.

LAT...LON 4127 8859 4113 8858 4113 8846 4122 8826
      4143 8827

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 15, 1:49 PM CDTSevere Thunderstorm WarningLOTWill41 min
May 15, 2:11 PM CDTSevere Thunderstorm WarningLOTKankakee34 min
May 15, 2:33 PM CDTTornado WarningLOTWill18 min
May 15, 2:45 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois46 min
May 15, 2:54 PM CDTSpecial Marine WarningLOT66 min
May 15, 2:54 PM CDTSpecial Marine WarningLOT66 min
May 15, 3:13 PM CDTSevere Thunderstorm WarningLOTIroquois43 min
May 15, 4:17 PM CDTSevere Thunderstorm WarningLOTWill12 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2007Every severe thunderstorm warning in 2007

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.