Alert archive / Missouri / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 452, NWS St. Louis, MO

July 12, 2011Knox County, Lewis County, Shelby County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 12, 2011, 2:08 PM CDT for Knox County, Lewis County, Shelby County, Missouri. It was in force for 52 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: Jul 12, 2011, 2:08 PM CDT (19:08 UTC)
Expired: Jul 12, 2011, 3:00 PM CDT
In force: 52 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.5 in
Wind: 70.0 mph

Counties Knox County, MO, Lewis County, MO, Shelby County, MO

The radar

The St Louis radar (KLSX), 189 km from the middle of the area, began a volume at 19:11 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
Jul 12, 2:20 PM CDT	TSTM WND GST 49	Novelty, MO
Jul 12, 2:27 PM CDT	TSTM WND GST 58	Novelty, MO
Jul 12, 2:33 PM CDT	HAIL 1.5	2 E Novelty, MO
Jul 12, 2:40 PM CDT	HAIL 0.25	3 Ese Novelty, MO
Jul 12, 3:05 PM CDT	HAIL 0.25	Steffenville, MO

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
Jul 12, 1:45 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 7.1 hours before the alert went out and 230 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: 1234 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: -49 m²/s²
0-3 km storm-relative helicity: 12 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

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

251 
WUUS53 KLSX 121908
SVRLSX
MOC103-111-205-122000-
/O.NEW.KLSX.SV.W.0452.110712T1908Z-110712T2000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
208 PM CDT TUE JUL 12 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN KNOX COUNTY IN NORTHEAST MISSOURI...
  SOUTHWESTERN LEWIS COUNTY IN NORTHEAST MISSOURI...
  NORTHERN SHELBY COUNTY IN NORTHEAST MISSOURI...

* UNTIL 300 PM CDT

* AT 207 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PING PONG BALL SIZE
  HAIL...AND DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS
  LOCATED 8 MILES SOUTH OF BRASHEAR...OR 8 MILES EAST OF LA PLATA...
  AND MOVING SOUTHEAST AT 35 MPH.

  THIS STORM PRODUCED 2 INCH HAIL AND 60 MPH WIND GUSTS IN ADAIR
  COUNTY.

* LOCATIONS IMPACTED INCLUDE...
  PLEVNA...SHELBYVILLE...STEFFENVILLE...NOVELTY...LEONARD...NEWARK
  AND BETHEL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4002 9184 3975 9205 3990 9229 3995 9230
      3995 9235 4016 9233
TIME...MOT...LOC 1908Z 298DEG 29KT 4004 9233
WIND...HAIL 70MPH 1.50IN

$$

JPK

1 follow-up statement

895 
WWUS53 KLSX 121932
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
232 PM CDT TUE JUL 12 2011

MOC103-111-205-122000-
/O.CON.KLSX.SV.W.0452.000000T0000Z-110712T2000Z/
KNOX MO-LEWIS MO-SHELBY MO-
232 PM CDT TUE JUL 12 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN
SHELBY...SOUTHWESTERN LEWIS AND SOUTHERN KNOX COUNTIES UNTIL 300 PM
CDT...

AT 228 PM CDT...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 
PLEVNA...OR 14 MILES SOUTH OF EDINA...MOVING SOUTHEAST AT 35 MPH. 
SURFACE OBSERVING EQUIPMENT IN NOVELTY REPORTED A WIND GUST OF
58 MPH AT 220 PM CDT. 

LOCATIONS IMPACTED INCLUDE...
  PLEVNA...SHELBYVILLE...STEFFENVILLE...NEWARK AND BETHEL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4014 9225 4002 9184 3975 9205 3990 9229
      3995 9230 3995 9235
TIME...MOT...LOC 1931Z 298DEG 29KT 3995 9212
WIND...HAIL 60MPH 1.00IN

$$

JPK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 1:58 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis	47 min
Jul 12, 2:25 PM CDT	Severe Thunderstorm Warning	LSX	Saint Louis, City of Saint Louis	26 min
Jul 12, 2:31 PM CDT	Flash Flood Warning	LSX	City of Saint Louis	3 hr
Jul 12, 2:36 PM CDT	Flash Flood Warning	LSX	Knox	2 hr
Jul 12, 2:54 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis, Marion, Shelby	51 min
Jul 12, 3:44 PM CDT	Severe Thunderstorm Warning	LSX	Marion, Ralls	46 min
Jul 12, 4:09 PM CDT	Severe Thunderstorm Warning	LSX	Madison	40 min
Jul 12, 4:21 PM CDT	Areal Flood Advisory	LSX	Saint Louis, City of Saint Louis	42 min
Jul 12, 4:21 PM CDT	Severe Thunderstorm Warning	LSX	Callaway	39 min
Jul 12, 4:31 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Pike	44 min
Jul 12, 4:45 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Osage	45 min
Jul 12, 5:03 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Saint Charles, Saint Louis	57 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.