Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 255, NWS St. Louis, MO

August 16, 2012Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 16, 2012, 4:26 PM CDT for Saint Clair County, Illinois. It was in force for 24 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 16, 2012, 4:26 PM CDT (21:26 UTC)
Expired
Aug 16, 2012, 4:50 PM CDT
In force
24 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Saint Clair County, IL

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 16, 1:05 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.4 hours before the alert went out and 215 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 2012-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 817 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2012-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
817 J/kg
Mixed-layer CIN
-262 J/kg
Mixed-layer LCL
1559 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

233 
WUUS53 KLSX 162126
SVRLSX
ILC163-162200-
/O.NEW.KLSX.SV.W.0255.120816T2126Z-120816T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
426 PM CDT THU AUG 16 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS...

* UNTIL 500 PM CDT

* AT 421 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR
  CENTREVILLE...AND MOVING EAST AT 35 MPH.

  HAZARD...QUARTER SIZE HAIL AND 60 MPH WIND GUSTS.

  SOURCE...RADAR INDICATED.

  IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS. MINOR TREE
           DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER BROKEN.

* LOCATIONS IMPACTED INCLUDE...
  O'FALLON...SHILOH...FREEBURG...SCOTT AFB...LEBANON...MASCOUTAH...
  SUMMERFIELD AND ST. LIBORY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

TO REPORT SEVERE WEATHER CONTACT YOUR NEAREST LAW ENFORCEMENT AGENCY.
THEY WILL SEND YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN ST
LOUIS.

&&

LAT...LON 3847 9014 3866 9008 3865 8971 3836 8970
TIME...MOT...LOC 2126Z 279DEG 38KT 3854 9000

HAIL...1.00IN
WIND...60 MPH

$$

GOSSELIN
2 follow-up statements
096 
WWUS53 KLSX 162140
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
440 PM CDT THU AUG 16 2012

ILC163-162200-
/O.CON.KLSX.SV.W.0255.000000T0000Z-120816T2200Z/
ST. CLAIR IL-
440 PM CDT THU AUG 16 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHEASTERN
ST. CLAIR COUNTY UNTIL 500 PM CDT...

AT 438 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR SCOTT AFB...
AND MOVING EAST AT 35 MPH.

HAZARD...QUARTER SIZE HAIL AND 60 MPH WIND GUSTS.

SOURCE...RADAR INDICATED.

IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS. MINOR TREE
         DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER BROKEN.

LOCATIONS IMPACTED INCLUDE...
SUMMERFIELD AND ST. LIBORY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

TO REPORT SEVERE WEATHER CONTACT YOUR NEAREST LAW ENFORCEMENT AGENCY.
THEY WILL SEND YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN ST
LOUIS.

TORRENTIAL RAINFALL IS OCCURRING WITH THIS STORM...AND MAY LEAD TO
FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS!

&&

LAT...LON 3842 8995 3866 8991 3865 8971 3836 8970
TIME...MOT...LOC 2140Z 279DEG 38KT 3852 8981

HAIL...1.00IN
WIND...60 MPH

$$

GOSSELIN
552 
WWUS53 KLSX 162150
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
450 PM CDT THU AUG 16 2012

ILC163-162200-
/O.CAN.KLSX.SV.W.0255.000000T0000Z-120816T2200Z/
ST. CLAIR IL-
450 PM CDT THU AUG 16 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ST. CLAIR COUNTY
IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND MOVED OUT OF
THE WARNED AREA.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 8 PM CDT.

LAT...LON 3842 8995 3866 8991 3865 8971 3836 8970
TIME...MOT...LOC 2150Z 279DEG 38KT 3850 8968

$$

GOSSELIN

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 16, 2:11 PM CDTSevere Thunderstorm WarningLSXCalhoun, Greene39 min
Aug 16, 3:08 PM CDTSevere Thunderstorm WarningLSXMacoupin, Madison37 min
Aug 16, 3:18 PM CDTSevere Thunderstorm WarningLSXMadison, Saint Clair42 min
Aug 16, 3:28 PM CDTSevere Thunderstorm WarningLSXMonroe47 min
Aug 16, 3:43 PM CDTSevere Thunderstorm WarningLSXSaint Clair47 min
Aug 16, 3:43 PM CDTSevere Thunderstorm WarningLSXBond, Fayette, Montgomery47 min
Aug 16, 3:52 PM CDTSevere Thunderstorm WarningLSXBond, Clinton, Madison38 min
Aug 16, 4:07 PM CDTSevere Thunderstorm WarningLSXClinton, Marion53 min
Aug 16, 4:25 PM CDTSevere Thunderstorm WarningLSXFayette35 min
Aug 16, 4:49 PM CDTSevere Thunderstorm WarningLSXClinton, Marion, Washington56 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2012Every severe thunderstorm warning in 2012

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.