Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 122, NWS St. Louis, MO

April 28, 2012Clinton County, Washington County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 28, 2012, 6:17 PM CDT for Clinton County, Washington County, Illinois. It was in force for 33 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: Apr 28, 2012, 6:17 PM CDT (23:17 UTC)
Expired: Apr 28, 2012, 6:50 PM CDT
In force: 33 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.75 in
Wind: 60.0 mph

Counties Clinton County, IL, Washington County, IL

The radar

The St Louis radar (KLSX), 115 km from the middle of the area, began a volume at 23:20 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.

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 28, 1:48 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Apr 28, 5:15 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 11.3 hours before the alert went out and 203 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1019 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 681 m²/s²
0-3 km storm-relative helicity: 811 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

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

391 
WUUS53 KLSX 282317
SVRLSX
ILC027-189-290000-
/O.NEW.KLSX.SV.W.0122.120428T2317Z-120429T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
617 PM CDT SAT APR 28 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN CLINTON COUNTY IN SOUTH CENTRAL ILLINOIS...
  NORTHERN WASHINGTON COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 700 PM CDT

* AT 611 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED JUST
  NORTHEAST OF OKAWVILLE...AND MOVING EAST AT 20 MPH.

  HAZARD...GOLF BALL 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...
  IRVINGTON...WAMAC...BARTELSO...COVINGTON...NEW MINDEN...POSEY...
  HUEGELY...HOYLETON...HOFFMAN AND RICHVIEW.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3836 8959 3855 8957 3854 8914 3835 8914
TIME...MOT...LOC 2316Z 266DEG 15KT 3846 8949

HAIL...1.75IN
WIND...60 MPH

$$

BYRD

2 follow-up statements

547 
WWUS53 KLSX 282339
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
639 PM CDT SAT APR 28 2012

ILC027-189-290000-
/O.CON.KLSX.SV.W.0122.000000T0000Z-120429T0000Z/
WASHINGTON IL-CLINTON IL-
639 PM CDT SAT APR 28 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL
CLINTON AND NORTHEASTERN WASHINGTON COUNTIES UNTIL 700 PM CDT...

AT 637 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED 9 MILES NORTH OF
NASHVILLE...AND MOVING EAST AT 25 MPH.

HAZARD...GOLF BALL SIZE HAIL AND 60 MPH WIND GUSTS.

SOURCE...RADAR INDICATED.

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

LOCATIONS IMPACTED INCLUDE...
IRVINGTON...WAMAC...HOYLETON AND HOFFMAN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3842 8914 3843 8943 3855 8943 3854 8914
TIME...MOT...LOC 2339Z 260DEG 21KT 3848 8933

HAIL...1.75IN
WIND...60 MPH

$$

BYRD

671 
WWUS53 KLSX 282350
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
650 PM CDT SAT APR 28 2012

ILC027-189-290001-
/O.CAN.KLSX.SV.W.0122.000000T0000Z-120429T0000Z/
WASHINGTON IL-CLINTON IL-
650 PM CDT SAT APR 28 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL CLINTON AND
NORTHEASTERN WASHINGTON COUNTIES IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

LAT...LON 3842 8914 3843 8943 3855 8943 3854 8914
TIME...MOT...LOC 2351Z 260DEG 21KT 3849 8924

$$

BYRD

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 2:26 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun	49 min
Apr 28, 3:05 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Jersey, Madison	40 min
Apr 28, 3:45 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Madison, Saint Clair	45 min
Apr 28, 3:59 PM CDT	Tornado Warning	LSX	Saint Clair	31 min
Apr 28, 4:22 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Saint Clair, Washington	38 min
Apr 28, 4:28 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Saint Clair, Washington	47 min
Apr 28, 4:56 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Saint Clair, Washington	49 min
Apr 28, 5:13 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Marion, Washington	47 min
Apr 28, 5:38 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Saint Clair, Washington	37 min
Apr 28, 5:50 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun	40 min
Apr 28, 6:01 PM CDT	Tornado Warning	LSX	Madison, Saint Clair	29 min
Apr 28, 6:10 PM CDT	Severe Thunderstorm Warning	LSX	Monroe	34 min
Apr 28, 6:27 PM CDT	Severe Thunderstorm Warning	LSX	Madison, Saint Clair	48 min
Apr 28, 6:35 PM CDT	Severe Thunderstorm Warning	LSX	Fayette, Marion	25 min
Apr 28, 6:53 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Saint Clair, Washington	52 min
Apr 28, 6:58 PM CDT	Severe Thunderstorm Warning	LSX	Fayette, Marion	32 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.