Alert archive / Missouri / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 11, NWS St. Louis, MO

February 28, 2011Washington County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Feb 28, 2011, 12:06 AM CST for Washington County, Missouri. It was in force for 39 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: Feb 28, 2011, 12:06 AM CST (06:06 UTC)
Expired: Feb 28, 2011, 12:45 AM CST
In force: 39 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 70.0 mph

County Washington County, MO

The radar

The St Louis radar (KLSX), 88 km from the middle of the area, began a volume at 06:05 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
Feb 27, 9:40 PM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 6.1 hours before the alert went out and 281 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: 626 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 1011 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 369 m²/s²
0-3 km storm-relative helicity: 472 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 7.4

Open this sounding in Storm Lab

The text

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

201 
WUUS53 KLSX 280606
SVRLSX
MOC221-280645-
/O.NEW.KLSX.SV.W.0011.110228T0606Z-110228T0645Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1206 AM CST MON FEB 28 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WASHINGTON COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 1245 AM CST

* AT 1205 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED 8
  MILES NORTH OF COURTOIS...OR 14 MILES WEST OF POTOSI...AND MOVING
  EAST AT 65 MPH.

* LOCATIONS IMPACTED INCLUDE...
  POTOSI...OLD MINES...MINERAL POINT...IRONDALE...SHIRLEY...LATTY...
  BELGRADE...CALEDONIA AND CADET.

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.

THIS STORM HAS EXHIBITED SOME WEAK ROTATION. TORNADOES CAN DEVELOP
QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH ONE IS 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.

&&

LAT...LON 3775 9111 3811 9110 3815 9073 3806 9064
      3774 9066
TIME...MOT...LOC 0606Z 263DEG 60KT 3788 9101
WIND...HAIL 70MPH 1.00IN

$$

GKS

1 follow-up statement

866 
WWUS53 KLSX 280647
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1247 AM CST MON FEB 28 2011

MOC221-280657-
/O.EXP.KLSX.SV.W.0011.000000T0000Z-110228T0645Z/
WASHINGTON MO-
1247 AM CST MON FEB 28 2011

...THE SEVERE THUNDERSTORM WARNING FOR WASHINGTON COUNTY HAS
EXPIRED...

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

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 400 AM.

LAT...LON 3775 9111 3811 9110 3815 9073 3806 9064
      3774 9066
TIME...MOT...LOC 0606Z 263DEG 60KT 3788 9101

$$

GKS

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 27, 6:26 PM CST	Severe Thunderstorm Warning	LSX	Lewis, Marion	49 min
Feb 27, 6:57 PM CST	Severe Thunderstorm Warning	LSX	Lewis, Marion	15 min
Feb 27, 7:38 PM CST	Severe Thunderstorm Warning	LSX	Marion, Ralls	37 min
Feb 27, 8:02 PM CST	Tornado Warning	LSX	Pike	28 min
Feb 27, 8:13 PM CST	Areal Flood Advisory	LSX	Marion	4 hr
Feb 27, 8:25 PM CST	Severe Thunderstorm Warning	LSX	Pike	35 min
Feb 27, 9:50 PM CST	Severe Thunderstorm Warning	LSX	Audrain, Pike, Ralls	40 min
Feb 27, 9:54 PM CST	Tornado Warning	LSX	Cole, Gasconade, Osage	36 min
Feb 27, 10:19 PM CST	Tornado Warning	LSX	Franklin, Gasconade, Warren	41 min
Feb 27, 10:25 PM CST	Tornado Warning	LSX	Franklin, Gasconade	50 min
Feb 27, 10:47 PM CST	Tornado Warning	LSX	Franklin, Jefferson, Saint Charles, Saint Louis, Warren, City of Saint Louis	43 min
Feb 27, 11:05 PM CST	River Flood Warning	LSX	Marion	35 hr
Feb 27, 11:11 PM CST	River Flood Warning	LSX	Lincoln	35 hr
Feb 27, 11:11 PM CST	River Flood Warning	LSX	Marion	35 hr
Feb 27, 11:11 PM CST	River Flood Warning	LSX	Monroe	4 days
Feb 27, 11:18 PM CST	Tornado Warning	LSX	Jefferson, Saint Charles, Saint Louis, City of Saint Louis	42 min
Feb 27, 11:47 PM CST	Severe Thunderstorm Warning	LSX	Crawford	21 min
Feb 28, 12:18 AM CST	Tornado Warning	LSX	Iron, Reynolds	42 min
Feb 28, 12:23 AM CST	Severe Thunderstorm Warning	LSX	Sainte Genevieve, Saint Francois	52 min
Feb 28, 12:44 AM CST	Tornado Warning	LSX	Iron, Madison, Sainte Genevieve, Saint Francois	46 min
Feb 28, 2:19 AM CST	River Flood Warning	LSX	Saint Charles	4 days
Feb 28, 6:46 AM CST	River Flood Warning	LSX	Marion	29 hr
Feb 28, 6:46 AM CST	River Flood Warning	LSX	Pike	38 hr
Feb 28, 6:46 AM CST	River Flood Warning	LSX	Pike	52 hr
Feb 28, 10:38 AM CST	River Flood Warning	LSX	Gasconade, Montgomery	4 days
Feb 28, 11:43 AM CST	River Flood Warning	LSX	Lincoln	47 hr

Nearby

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.