Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 254, NWS St. Louis, MO

August 16, 2012Fayette County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 16, 2012, 4:25 PM CDT for Fayette County, Illinois. It was in force for 35 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, 4:25 PM CDT (21:25 UTC)
Expired
Aug 16, 2012, 5:00 PM CDT
In force
35 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
70.0 mph

County Fayette 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 141 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.

593 
WUUS53 KLSX 162125
SVRLSX
ILC051-162200-
/O.NEW.KLSX.SV.W.0254.120816T2125Z-120816T2200Z/

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

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN FAYETTE COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 500 PM CDT

* AT 421 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR SHOBONIER...
  AND MOVING EAST AT 40 MPH.

  HAZARD...QUARTER SIZE HAIL AND 70 MPH WIND GUSTS.

  SOURCE...RADAR INDICATED.

  IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS. TREE
           BRANCHES UP TO THREE INCHES IN DIAMETER BROKEN. POSSIBLE
           MINOR DAMAGE TO SHINGLE ROOFS AND METAL OUTBUILDINGS.

* LOCATIONS IMPACTED INCLUDE...
  BROWNSTOWN...ST. ELMO...FARINA...ST. PAUL...AVENA...ST. JAMES...
  LOOGOOTEE...ST. PETER AND LA CLEDE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMAIN ALERT FOR A POSSIBLE TORNADO! TORNADOES CAN DEVELOP QUICKLY
FROM SEVERE THUNDERSTORMS. IF YOU SPOT A TORNADO GO AT ONCE INTO THE
BASEMENT OR SMALL CENTRAL ROOM IN A STURDY STRUCTURE.

PREPARE IMMEDIATELY FOR LARGE HAIL AND DAMAGING WINDS. PEOPLE OUTSIDE
SHOULD MOVE TO A SHELTER...INSIDE A STRONG BUILDING AND AWAY FROM
WINDOWS.

&&

LAT...LON 3882 8874 3882 8893 3883 8916 3900 8915
      3906 8880 3892 8880 3892 8870 3891 8868
      3883 8869
TIME...MOT...LOC 2125Z 276DEG 35KT 3889 8906

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70 MPH

$$

BRITT
1 follow-up statement
797 
WWUS53 KLSX 162154
SVSLSX

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

ILC051-162204-
/O.EXP.KLSX.SV.W.0254.000000T0000Z-120816T2200Z/
FAYETTE IL-
454 PM CDT THU AUG 16 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN FAYETTE COUNTY WILL
EXPIRE AT 500 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS 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 3882 8874 3882 8893 3883 8916 3900 8915
      3906 8880 3892 8880 3892 8870 3891 8868
      3883 8869
TIME...MOT...LOC 2154Z 276DEG 35KT 3886 8870

$$

BRITT

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, 4:26 PM CDTSevere Thunderstorm WarningLSXSaint Clair24 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.