Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 150, NWS St. Louis, MO

May 4, 2012Clinton County, Saint Clair County, Washington County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 4, 2012, 11:11 AM CDT for Clinton County, Saint Clair County, Washington County, Illinois. It was in force for 34 min. 3 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
May 4, 2012, 11:11 AM CDT (16:11 UTC)
Expired
May 4, 2012, 11:45 AM CDT
In force
34 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Clinton County, IL, Saint Clair County, IL, Washington County, IL

The radar

The St Louis radar (KLSX), 81 km from the middle of the area, began a volume at 16:15 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
May 4, 11:24 AM CDTHAIL 1.251 E Floraville, ILQUARTER TO HALF DOLLAR SIZE HAIL.
May 4, 11:25 AM CDTHAIL 0.5Smithton, IL
May 4, 11:33 AM CDTHAIL 0.252 N New Athens, IL

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

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 4.2 hours before the alert went out and 225 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 2012-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1160 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
170 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

430 
WUUS53 KLSX 041611
SVRLSX
ILC027-163-189-041645-
/O.NEW.KLSX.SV.W.0150.120504T1611Z-120504T1645Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1111 AM CDT FRI MAY 4 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN CLINTON COUNTY IN SOUTH CENTRAL ILLINOIS...
  SOUTHERN ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS...
  WESTERN WASHINGTON COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 1145 AM CDT

* AT 1110 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR SMITHTON...
  AND MOVING EAST AT 50 MPH.

  HAZARD...QUARTER SIZE HAIL.

  SOURCE...RADAR INDICATED.

  IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.

* LOCATIONS IMPACTED INCLUDE...
  FREEBURG...SMITHTON...NEW ATHENS...NEW MEMPHIS...LIVELY GROVE...
  OKAWVILLE...FAYETTEVILLE...LENZBURG...ST. LIBORY...JOHANNISBURG...
  VENEDY AND STONE CHURCH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3822 8960 3829 8991 3831 8991 3831 8996
      3832 9004 3841 9015 3843 9015 3853 9012
      3849 8966 3847 8958 3844 8954
TIME...MOT...LOC 1612Z 283DEG 42KT 3842 9001

HAIL...1.00IN
WIND...<50 MPH

$$

CARNEY
3 follow-up statements
103 
WWUS53 KLSX 041623
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1123 AM CDT FRI MAY 4 2012

ILC027-041633-
/O.CAN.KLSX.SV.W.0150.000000T0000Z-120504T1645Z/
CLINTON IL-
1123 AM CDT FRI MAY 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR EXTREME SOUTHWESTERN CLINTON
COUNTY IS CANCELLED...

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

LAT...LON 3822 8960 3829 8991 3831 8991 3831 8996
      3834 9007 3837 9009 3841 9008 3852 9001
      3846 8970 3842 8970 3845 8964 3843 8957
TIME...MOT...LOC 1623Z 290DEG 28KT 3839 8997

$$

ILC163-189-041645-
/O.CON.KLSX.SV.W.0150.000000T0000Z-120504T1645Z/
ST. CLAIR IL-WASHINGTON IL-
1123 AM CDT FRI MAY 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR WESTERN
WASHINGTON AND SOUTHERN ST. CLAIR COUNTIES UNTIL 1145 AM CDT...

AT 1119 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR SMITHTON...
AND MOVING EAST AT 30 MPH.

HAZARD...QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED.

IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.

LOCATIONS IMPACTED INCLUDE...
FREEBURG...NEW ATHENS...LIVELY GROVE...FAYETTEVILLE...LENZBURG...ST.
LIBORY...JOHANNISBURG...STONE CHURCH AND VENEDY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3822 8960 3829 8991 3831 8991 3831 8996
      3834 9007 3837 9009 3841 9008 3852 9001
      3846 8970 3842 8970 3845 8964 3843 8957
TIME...MOT...LOC 1623Z 290DEG 28KT 3839 8997

HAIL...1.00IN
WIND...<50 MPH

$$

CARNEY
290 
WWUS53 KLSX 041637
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1137 AM CDT FRI MAY 4 2012

ILC163-189-041645-
/O.CON.KLSX.SV.W.0150.000000T0000Z-120504T1645Z/
ST. CLAIR IL-WASHINGTON IL-
1137 AM CDT FRI MAY 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHWESTERN
WASHINGTON AND SOUTHEASTERN ST. CLAIR COUNTIES UNTIL 1145 AM CDT...

AT 1133 AM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR NEW ATHENS...
AND MOVING EAST AT 30 MPH.

HAZARD...QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED.

IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.

LOCATIONS IMPACTED INCLUDE...
LIVELY GROVE...FAYETTEVILLE...LENZBURG...ST. LIBORY...JOHANNISBURG...
STONE CHURCH AND VENEDY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HALF DOLLAR SIZED HAIL WAS REPORTED WITH THIS STORM AT 1124 AM ONE 
MILE EAST OF FLORAVILLE.  FOR YOUR PROTECTION MOVE TO AN INTERIOR 
ROOM ON THE LOWEST FLOOR OF A BUILDING.  

&&

LAT...LON 3822 8960 3829 8991 3832 8993 3849 8987
      3846 8971 3842 8970 3845 8964 3843 8957
TIME...MOT...LOC 1636Z 290DEG 28KT 3835 8985

HAIL...1.00IN
WIND...<50 MPH

$$

CARNEY
760 
WWUS53 KLSX 041644
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1144 AM CDT FRI MAY 4 2012

ILC163-189-041654-
/O.EXP.KLSX.SV.W.0150.000000T0000Z-120504T1645Z/
ST. CLAIR IL-WASHINGTON IL-
1144 AM CDT FRI MAY 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WASHINGTON AND
SOUTHEASTERN ST. CLAIR COUNTIES WILL EXPIRE AT 1145 AM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
HOWEVER SMALL HAIL...GUSTY WINDS AND HEAVY RAIN ARE STILL POSSIBLE 
WITH THIS THUNDERSTORM.

LAT...LON 3822 8960 3829 8991 3832 8993 3849 8987
      3846 8971 3842 8970 3845 8964 3843 8957
TIME...MOT...LOC 1644Z 290DEG 28KT 3833 8978

$$

CARNEY

The office that day

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

IssuedProductOfficeCountiesLasted
May 4, 4:03 AM CDTSevere Thunderstorm WarningLSXAdams, Brown42 min
May 4, 6:27 AM CDTSevere Thunderstorm WarningLSXMacoupin33 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.