Alert archive / Missouri / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 123, NWS St. Louis, MO

April 28, 2012Saint Louis County, City of Saint Louis, Missouri; Madison County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 28, 2012, 6:27 PM CDT for Saint Louis County, City of Saint Louis, Missouri; Madison County, Saint Clair County, Illinois. It was in force for 48 min. 5 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: Apr 28, 2012, 6:27 PM CDT (23:27 UTC)
Expired: Apr 28, 2012, 7:15 PM CDT
In force: 48 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Tornado: Possible
Hail: 1.75 in
Wind: 60.0 mph

Counties Madison County, IL, Saint Clair County, IL, City of Saint Louis, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 55 km from the middle of the area, began a volume at 23:28 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
Apr 28, 6:29 PM CDT	HAIL 1.75	2 Sw Brooklyn, MO	GOLFBALL SIZED HAIL AT TUCKER AND MARKET.
Apr 28, 6:29 PM CDT	HAIL 3	St. Louis, MO	ON NORTH SIDE OF TOWN.
Apr 28, 6:30 PM CDT	HAIL 1.75	St. Louis, MO	HAMPTON AND I-44.
Apr 28, 6:33 PM CDT	HAIL 1	St. Louis, MO	FROM THE KMOV WEATHER CAMERA.
Apr 28, 6:36 PM CDT	TSTM WND GST 52	1 Ese Sauget, IL

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
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, 11.5 hours before the alert went out and 218 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.

495 
WUUS53 KLSX 282327
SVRLSX
ILC119-163-MOC189-510-290015-
/O.NEW.KLSX.SV.W.0123.120428T2327Z-120429T0015Z/

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

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN MADISON COUNTY IN SOUTHWEST ILLINOIS...
  ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS...
  EAST CENTRAL ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...
  ST. LOUIS CITY IN EAST CENTRAL MISSOURI...

* UNTIL 715 PM CDT

* AT 624 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR ST. LOUIS...
  AND MOVING EAST AT 40 MPH.

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

  SOURCE...TRAINED WEATHER SPOTTERS.

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

  GOLF BALL SIZE HAIL WAS REPORTED WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...
  MADISON...GRANITE CITY...DUPO...CAHOKIA...EAST ST. LOUIS...PONTOON
  BEACH...WASHINGTON PARK...CENTREVILLE...CASEYVILLE...
  COLLINSVILLE...MARYVILLE...MILLSTADT...FAIRVIEW HEIGHTS...
  BELLEVILLE...SWANSEA...O'FALLON...SHILOH...FREEBURG...SCOTT AFB AND
  LEBANON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3826 8976 3842 9015 3843 9015 3852 9026
      3849 9027 3855 9037 3870 9027 3875 9019
      3878 9018 3877 9017 3880 9012 3865 8971
      3839 8970
TIME...MOT...LOC 2327Z 291DEG 36KT 3863 9019

TORNADO...POSSIBLE
HAIL...1.75IN
WIND...60 MPH

$$

KANOFSKY

1 follow-up statement

124 
WWUS53 KLSX 290010
SVSLSX

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

ILC119-163-MOC189-510-290020-
/O.EXP.KLSX.SV.W.0123.000000T0000Z-120429T0015Z/
MADISON IL-ST. CLAIR IL-ST. LOUIS MO-ST. LOUIS CITY MO-
710 PM CDT SAT APR 28 2012

...THE SEVERE THUNDERSTORM WARNING FOR ST. LOUIS CITY...EAST CENTRAL
ST. LOUIS...ST. CLAIR AND SOUTHWESTERN MADISON COUNTIES WILL EXPIRE
AT 715 PM 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 IS STILL POSSIBLE WITH THIS THUNDERSTORM.

IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 10 PM CDT.

LAT...LON 3826 8976 3842 9015 3843 9015 3852 9026
      3849 9027 3855 9037 3870 9027 3875 9019
      3878 9018 3877 9017 3880 9012 3865 8971
      3839 8970
TIME...MOT...LOC 0010Z 291DEG 36KT 3847 8968

$$

KANOFSKY

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 1:14 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Montgomery	46 min
Apr 28, 1:50 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Montgomery, Warren	40 min
Apr 28, 2:26 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Saint Charles, Warren	49 min
Apr 28, 3:05 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Saint Louis, City of Saint Louis	40 min
Apr 28, 3:45 PM CDT	Severe Thunderstorm Warning	LSX	Saint Louis, City of Saint Louis	45 min
Apr 28, 4:12 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Boone, Callaway	38 min
Apr 28, 4:49 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Washington	41 min
Apr 28, 4:55 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Montgomery, Warren	50 min
Apr 28, 5:19 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Saint Charles, Warren	41 min
Apr 28, 5:27 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Jefferson, Saint Francois, Washington	48 min
Apr 28, 5:50 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles, Saint Louis	40 min
Apr 28, 6:01 PM CDT	Tornado Warning	LSX	Saint Charles, Saint Louis, City of Saint Louis	29 min
Apr 28, 6:10 PM CDT	Severe Thunderstorm Warning	LSX	Jefferson, Sainte Genevieve, Saint Francois, Washington	34 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, 6:17 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Washington	33 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 Missouri, 2012 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.