Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 322, NWS St. Louis, MO

September 25, 2012Monroe County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Sep 25, 2012, 6:50 PM CDT for Monroe County, Saint Clair County, Illinois. It was in force for 46 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: Sep 25, 2012, 6:50 PM CDT (23:50 UTC)
Expired: Sep 25, 2012, 7:36 PM CDT
In force: 46 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Monroe County, IL, Saint Clair County, IL

The radar

The St Louis radar (KLSX), 56 km from the middle of the area, began a volume at 23:50 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

Time	Report	Where	Remark
Sep 25, 7:11 PM CDT	TSTM WND GST 49	Smithton, IL	AT THE RESIDENCE OF AN AMATEUR RADIO OPERATOR.

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.

Issued	Product	Office	Lasted
Sep 25, 5:05 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 11.8 hours before the alert went out and 239 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: 221 J/kg
Mixed-layer CIN: -192 J/kg
Mixed-layer LCL: 560 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 108 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.7

Open this sounding in Storm Lab

The text

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

803 
WUUS53 KLSX 252350
SVRLSX
ILC133-163-260045-
/O.NEW.KLSX.SV.W.0322.120925T2350Z-120926T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
650 PM CDT TUE SEP 25 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

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

* UNTIL 745 PM CDT

* AT 646 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR VALMEYER...
  AND MOVING EAST AT 30 MPH.

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

  SOURCE...TRAINED WEATHER SPOTTERS.  QUARTER SIZE HAIL WAS REPORTED
           IN BARNHART MISSOURI WITH THIS STORM.

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

* LOCATIONS IMPACTED INCLUDE...
  COLUMBIA...WATERLOO...MILLSTADT...BELLEVILLE...SWANSEA...
  FREEBURG...O'FALLON...SHILOH...SCOTT AFB...MASCOUTAH...LEBANON...
  FOUNTAIN...NEW DESIGN...SMITHTON...NEW ATHENS...MARISSA...MONROE
  CITY...MADONNAVILLE...FOSTER POND AND NEW HANDOVER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM IS PRODUCING LARGE HAIL. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.

&&

LAT...LON 3825 9037 3834 9037 3839 9034 3845 9028
      3850 9027 3865 8971 3824 8970
TIME...MOT...LOC 2348Z 262DEG 26KT 3834 9032

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

$$

BRITT

3 follow-up statements

767 
WWUS53 KLSX 260010
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
710 PM CDT TUE SEP 25 2012

ILC133-260019-
/O.CAN.KLSX.SV.W.0322.000000T0000Z-120926T0045Z/
MONROE IL-
710 PM CDT TUE SEP 25 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN MONROE COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.  ADDITIONAL STRONG STORMS ARE POSSIBLE AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 11 PM CDT.

LAT...LON 3824 8971 3824 8991 3828 8992 3828 8990
      3831 8991 3831 9003 3832 9004 3841 9015
      3843 9015 3851 9024 3865 8971
TIME...MOT...LOC 0009Z 265DEG 40KT 3839 8993

$$

ILC163-260045-
/O.CON.KLSX.SV.W.0322.000000T0000Z-120926T0045Z/
ST. CLAIR IL-
710 PM CDT TUE SEP 25 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR ST. CLAIR
COUNTY UNTIL 745 PM CDT...

AT 704 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR SMITHTON...AND
MOVING EAST AT 45 MPH.

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

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...
FREEBURG...O'FALLON...SHILOH...SCOTT AFB...MASCOUTAH...LEBANON...NEW
ATHENS...MARISSA...LENZBURG...FAYETTEVILLE...SUMMERFIELD AND ST.
LIBORY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3824 8971 3824 8991 3828 8992 3828 8990
      3831 8991 3831 9003 3832 9004 3841 9015
      3843 9015 3851 9024 3865 8971
TIME...MOT...LOC 0009Z 265DEG 40KT 3839 8993

HAIL...0.88IN
WIND...60 MPH

$$

BRITT

079 
WWUS53 KLSX 260025
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
725 PM CDT TUE SEP 25 2012

ILC163-260045-
/O.CON.KLSX.SV.W.0322.000000T0000Z-120926T0045Z/
ST. CLAIR IL-
725 PM CDT TUE SEP 25 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
ST. CLAIR COUNTY UNTIL 745 PM CDT...

AT 722 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED 7 MILES NORTHEAST
OF NEW ATHENS...AND MOVING EAST AT 35 MPH.

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

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...
ST. LIBORY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3824 8991 3828 8992 3828 8990 3844 8991
      3851 8971 3844 8971 3843 8970 3843 8971
      3839 8971 3824 8971
TIME...MOT...LOC 0025Z 265DEG 32KT 3839 8975

HAIL...0.88IN
WIND...60 MPH

$$

BRITT

879 
WWUS53 KLSX 260036
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
736 PM CDT TUE SEP 25 2012

ILC163-260045-
/O.CAN.KLSX.SV.W.0322.000000T0000Z-120926T0045Z/
ST. CLAIR IL-
736 PM CDT TUE SEP 25 2012

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

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 11 PM CDT.

LAT...LON 3824 8991 3828 8992 3828 8990 3844 8991
      3851 8971 3844 8971 3843 8970 3843 8971
      3839 8971 3824 8971
TIME...MOT...LOC 0035Z 265DEG 32KT 3840 8964

$$

BRITT

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 25, 3:38 AM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton, Fayette, Marion	22 min
Sep 25, 4:36 AM CDT	Areal Flood Advisory	LSX	Pike	5 hr
Sep 25, 4:29 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Madison, Saint Clair	46 min
Sep 25, 4:39 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Saint Clair	51 min
Sep 25, 5:05 PM CDT	Severe Thunderstorm Warning	LSX	Clinton	55 min
Sep 25, 5:07 PM CDT	Tornado Warning	LSX	Clinton	23 min
Sep 25, 5:09 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Jersey, Madison	51 min
Sep 25, 5:12 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Saint Clair	18 min
Sep 25, 5:19 PM CDT	Tornado Warning	LSX	Washington	26 min
Sep 25, 5:28 PM CDT	Severe Thunderstorm Warning	LSX	Marion	47 min
Sep 25, 5:34 PM CDT	Tornado Warning Tornado observed	LSX	Washington	41 min
Sep 25, 5:43 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Washington	62 min
Sep 25, 6:08 PM CDT	Severe Thunderstorm Warning	LSX	Madison, Monroe, Saint Clair	52 min
Sep 25, 6:14 PM CDT	Severe Thunderstorm Warning	LSX	Washington	46 min
Sep 25, 6:19 PM CDT	Areal Flood Advisory	LSX	Clinton, Marion, Washington	6 hr
Sep 25, 6:30 PM CDT	Severe Thunderstorm Warning	LSX	Marion	26 min
Sep 25, 6:45 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Madison, Marion, Washington	45 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2012 Every 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.