Alert archive / Illinois / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 20, NWS St. Louis, MO

March 4, 2011Calhoun County, Jersey County, Madison County, Illinois; Saint Charles County, Saint Louis County, City of Saint Louis, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Mar 4, 2011, 5:23 PM CST for Calhoun County, Jersey County, Madison County, Illinois; Saint Charles County, Saint Louis County, City of Saint Louis, Missouri. It was in force for 29 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: Mar 4, 2011, 5:23 PM CST (23:23 UTC)
Expired: Mar 4, 2011, 5:52 PM CST
In force: 29 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Calhoun County, IL, Jersey County, IL, Madison County, IL, City of Saint Louis, MO, Saint Charles County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 23 km from the middle of the area, began a volume at 23:23 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
Mar 4, 5:23 PM CST	HAIL 0.25	O'Fallon, MO	MULTIPLE REPORTS ACROSS WESTERN ST. CHARLES COUNTY

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
Mar 4, 1:33 PM CST	Severe Thunderstorm Watch	SPC	5 hr
Mar 4, 4:54 PM CST	Tornado Watch	SPC	118 min

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 11.4 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: 1266 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 213 m²/s²
0-3 km storm-relative helicity: 228 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.

551 
WUUS53 KLSX 042323
SVRLSX
ILC013-083-119-MOC183-189-510-050015-
/O.NEW.KLSX.SV.W.0020.110304T2323Z-110305T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
523 PM CST FRI MAR 4 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN CALHOUN COUNTY IN SOUTHWEST ILLINOIS...
  SOUTHERN JERSEY COUNTY IN SOUTHWEST ILLINOIS...
  WESTERN MADISON COUNTY IN SOUTHWEST ILLINOIS...
  ST. CHARLES COUNTY IN EAST CENTRAL MISSOURI...
  NORTHERN ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...
  NORTHERN ST. LOUIS CITY IN EAST CENTRAL MISSOURI...

* UNTIL 615 PM CST

* AT 519 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  DARDENNE PRAIRIE...AND MOVING EAST AT 45 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WELDON SPRING...COTTLEVILLE...CHESTERFIELD...ST. PETERS...ST.
  CHARLES...MARYLAND HEIGHTS...CREVE COEUR...BRIDGETON...OLIVETTE...
  ST. ANN...OVERLAND...WOODSON TERRACE...HAZELWOOD...ST. JOHN...
  CLAYTON...UNIVERSITY CITY...BERKELEY...BEL-RIDGE...KINLOCH AND
  FLORISSANT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES LEADING KILLERS. REMEMBER...
IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY
LIGHTNING.

&&

LAT...LON 3866 9018 3865 9018 3863 9083 3888 9089
      3889 9086 3888 9081 3890 9081 3892 9073
      3891 9071 3893 9070 3894 9067 3909 9016
      3900 9015 3900 9009 3866 8999
TIME...MOT...LOC 2323Z 260DEG 40KT 3876 9068
WIND...HAIL 60MPH 1.00IN

$$

CARNEY

1 follow-up statement

070 
WWUS53 KLSX 042352
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
552 PM CST FRI MAR 4 2011

ILC013-083-119-MOC183-189-510-050001-
/O.CAN.KLSX.SV.W.0020.000000T0000Z-110305T0015Z/
MADISON IL-JERSEY IL-CALHOUN IL-ST. LOUIS CITY MO-ST. LOUIS MO-
ST. CHARLES MO-
552 PM CST FRI MAR 4 2011

...THE SEVERE THUNDERSTORM WARNING FOR ST. CHARLES...NORTHERN ST.
LOUIS...NORTHERN ST. LOUIS CITY...SOUTHERN CALHOUN...SOUTHERN JERSEY
AND WESTERN MADISON 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.
HOWEVER SMALL HAIL...GUSTY WINDS...FREQUENT LIGHTNING...AND HEAVY 
RAIN ARE STILL POSSIBLE WITH THIS THUNDERSTORM.

IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 1000 PM.

LAT...LON 3866 9018 3865 9018 3863 9083 3888 9089
      3889 9086 3888 9081 3890 9081 3892 9073
      3891 9071 3893 9070 3894 9067 3909 9016
      3900 9015 3900 9009 3866 8999
TIME...MOT...LOC 2351Z 260DEG 40KT 3881 9029

$$

CARNEY

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 4, 4:39 PM CST	Severe Thunderstorm Warning	LSX	Calhoun, Greene, Jersey	51 min
Mar 4, 4:40 PM CST	Tornado Warning	LSX	Calhoun, Greene, Pike	51 min
Mar 4, 2:47 PM CST	Severe Thunderstorm Warning	LSX	Boone	43 min
Mar 4, 3:13 PM CST	Severe Thunderstorm Warning	LSX	Callaway, Cole, Moniteau, Osage	47 min
Mar 4, 3:20 PM CST	Severe Thunderstorm Warning	LSX	Audrain, Boone	40 min
Mar 4, 3:28 PM CST	Severe Thunderstorm Warning	LSX	Audrain, Boone, Callaway, Montgomery	47 min
Mar 4, 3:34 PM CST	Tornado Warning	LSX	Boone, Callaway, Montgomery	41 min
Mar 4, 3:45 PM CST	Severe Thunderstorm Warning	LSX	Audrain, Monroe, Ralls	45 min
Mar 4, 3:49 PM CST	Tornado Warning	LSX	Audrain, Monroe, Pike, Ralls	56 min
Mar 4, 3:59 PM CST	Severe Thunderstorm Warning	LSX	Audrain, Callaway, Franklin, Gasconade, Lincoln, Montgomery and 3 more	46 min
Mar 4, 4:27 PM CST	Tornado Warning	LSX	Lincoln, Montgomery, Warren	33 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2011 Severe Thunderstorm Warnings in Missouri, 2011 Every severe thunderstorm warning in 2011

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.