Alert archive / Missouri / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 451, NWS St. Louis, MO

July 12, 2011Knox County, Lewis County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 12, 2011, 1:58 PM CDT for Knox County, Lewis County, Missouri. It was in force for 47 min. 2 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, 1:58 PM CDT (18:58 UTC)
Expired: Jul 12, 2011, 2:45 PM CDT
In force: 47 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Knox County, MO, Lewis County, MO

The radar

The Quad Cities radar (KDVN), 194 km from the middle of the area, began a volume at 18:58 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
Jul 12, 2:14 PM CDT	HAIL 0.88	3 Sw Colony, MO
Jul 12, 2:20 PM CDT	HAIL 0.88	3 Sw Colony, 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, 7.0 hours before the alert went out and 199 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.

315 
WUUS53 KLSX 121858
SVRLSX
MOC103-111-121945-
/O.NEW.KLSX.SV.W.0451.110712T1858Z-110712T1945Z/

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

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN KNOX COUNTY IN NORTHEAST MISSOURI...
  NORTHWESTERN LEWIS COUNTY IN NORTHEAST MISSOURI...

* UNTIL 245 PM CDT

* AT 154 PM CDT...A SEVERE THUNDERSTORM WAS REPORTED WAS LOCATED
  NEAR EDINA...AND MOVING EAST AT 15 MPH. THIS STORM WILL LIKELY
  PRODUCE ONE INCH HAIL AND 60 MPH WIND GUST. 

* LOCATIONS IMPACTED INCLUDE...
  COLONY...KNOX CITY AND LA BELLE.

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 4027 9194 4026 9194 4026 9190 4025 9181
      4006 9194 4015 9227 4031 9219
TIME...MOT...LOC 1857Z 282DEG 13KT 4020 9209
WIND...HAIL 60MPH 1.00IN

$$

JPK

2 follow-up statements

691 
WWUS53 KLSX 121927
SVSLSX

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

MOC103-111-121945-
/O.CON.KLSX.SV.W.0451.000000T0000Z-110712T1945Z/
KNOX MO-LEWIS MO-
227 PM CDT TUE JUL 12 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
LEWIS AND NORTHEASTERN KNOX COUNTIES UNTIL 245 PM CDT...

AT 223 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 KNOX
CITY...OR 11 MILES EAST OF EDINA...MOVING EAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE...
  LA BELLE.

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 4029 9208 4027 9194 4026 9194 4026 9190
      4025 9181 4006 9194 4013 9218
TIME...MOT...LOC 1927Z 282DEG 13KT 4018 9195
WIND...HAIL 60MPH 1.00IN

$$

JPK

130 
WWUS53 KLSX 121940
SVSLSX

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

MOC103-111-121950-
/O.EXP.KLSX.SV.W.0451.000000T0000Z-110712T1945Z/
KNOX MO-LEWIS MO-
240 PM CDT TUE JUL 12 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN LEWIS AND
NORTHEASTERN KNOX COUNTIES WILL EXPIRE AT 245 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 HEAVY RAIN THAT MAY CAURS LOCAL FLOODING IS STILL POSSIBLE 
WITH THIS THUNDERSTORM.

LAT...LON 4029 9208 4027 9194 4026 9194 4026 9190
      4025 9181 4006 9194 4013 9218
TIME...MOT...LOC 1940Z 282DEG 13KT 4017 9189

$$

JPK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 2:08 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis, Shelby	52 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.