Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 260, NWS St. Louis, MO

September 5, 2012Fayette County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Sep 5, 2012, 9:40 AM CDT for Fayette County, Illinois. It was in force for 50 min. 2 reports 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
Sep 5, 2012, 9:40 AM CDT (14:40 UTC)
Expired
Sep 5, 2012, 10:30 AM CDT
In force
50 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

County Fayette County, IL

The radar

The Lincoln radar (KILX), 126 km from the middle of the area, began a volume at 14:42 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
Sep 5, 9:42 AM CDTTSTM WND DMG5 E Ramsey, ILTREES AND POWER LINES DOWN BETWEEN RAMSEY AND WRIGHTS CORNER.
Sep 5, 9:55 AM CDTTSTM WND DMG4 N St. Elmo, ILPOWER POLE DOWN NOT BLOCKING ROADWAY NORTH OF ST. ELMOS...CONFIRMED BY FIRE DEPARTMENT ON SCANNER.

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

The watch it was issued in

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

IssuedProductOfficeLasted
Sep 5, 9:37 AM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 2.7 hours before the alert went out and 125 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 2012-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1271 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 2012-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 107 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
1271 J/kg
Mixed-layer CIN
-188 J/kg
Mixed-layer LCL
1037 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
107 m²/s²
0-3 km storm-relative helicity
138 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

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

718 
WUUS53 KLSX 051440
SVRLSX
ILC051-051530-
/O.NEW.KLSX.SV.W.0260.120905T1440Z-120905T1530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
940 AM CDT WED SEP 5 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

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

* UNTIL 1030 AM CDT

* AT 936 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED 5 MILES SOUTHEAST
  OF RAMSEY...AND MOVING EAST AT 40 MPH.

  HAZARD...60 MPH WIND GUSTS.

  SOURCE...TRAINED WEATHER SPOTTERS HAVE REPORTED WIDESPREAD WIND 
           DAMAGE WITH THIS STORM.

  IMPACT...MINOR TREE DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER
           BROKEN.

* LOCATIONS IMPACTED INCLUDE...
  BROWNSTOWN...WRIGHTS CORNER...ST. ELMO...AVENA AND ST. JAMES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

THIS IS A DANGEROUS SITUATION. THIS STORM IS PRODUCING WIDESPREAD 
WIND DAMAGE ACROSS PORTIONS OF MONTGOMERY AND FAYETTE COUNTIES. SEEK 
SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.

&&

LAT...LON 3892 8881 3902 8920 3922 8915 3922 8880
TIME...MOT...LOC 1439Z 292DEG 35KT 3910 8898

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60 MPH

$$

TILLY
2 follow-up statements
846 
WWUS53 KLSX 051507
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1007 AM CDT WED SEP 5 2012

ILC051-051530-
/O.CON.KLSX.SV.W.0260.000000T0000Z-120905T1530Z/
FAYETTE IL-
1007 AM CDT WED SEP 5 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CENTRAL
FAYETTE COUNTY UNTIL 1030 AM CDT...

AT 1003 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR ALTAMONT...
AND MOVING EAST AT 40 MPH.

HAZARD...60 MPH WIND GUSTS.

SOURCE...TRAINED WEATHER SPOTTERS HAVE REPORTED POWER POLES SNAPPED 
         JUST NORTH OF ST. ELMO.

IMPACT...MINOR TREE DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER
         BROKEN.

LOCATIONS IMPACTED INCLUDE...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. THIS STORM IS PRODUCING WIDESPREAD 
WIND DAMAGE. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY 
AWAY FROM WINDOWS.

&&

LAT...LON 3892 8881 3900 8910 3919 8881
TIME...MOT...LOC 1506Z 288DEG 33KT 3902 8870

HAIL...<.75IN
WIND...60 MPH

$$

TILLY
454 
WWUS53 KLSX 051525
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1025 AM CDT WED SEP 5 2012

ILC051-051535-
/O.EXP.KLSX.SV.W.0260.000000T0000Z-120905T1530Z/
FAYETTE IL-
1025 AM CDT WED SEP 5 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL FAYETTE COUNTY WILL
EXPIRE AT 1030 AM 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 500 PM.

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

LAT...LON 3892 8881 3900 8910 3919 8881
TIME...MOT...LOC 1525Z 291DEG 24KT 3896 8859

$$

TILLY

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 5, 3:07 AM CDTHeat AdvisoryLSXMadison, Monroe, Randolph, Saint Clair12 hr
Sep 5, 6:36 AM CDTSevere Thunderstorm WarningLSXAdams, Brown, Pike30 min
Sep 5, 7:56 AM CDTSevere Thunderstorm WarningLSXGreene, Macoupin, Montgomery64 min
Sep 5, 8:38 AM CDTSevere Thunderstorm WarningLSXFayette, Montgomery37 min
Sep 5, 9:08 AM CDTTornado WarningLSXFayette, Montgomery37 min
Sep 5, 10:00 AM CDTSevere Thunderstorm WarningLSXClinton, Fayette, Marion48 min
Sep 5, 10:23 AM CDTSevere Thunderstorm WarningLSXMonroe, Saint Clair32 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.