Alert archive / Illinois / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 470, NWS St. Louis, MO

July 24, 2011Randolph County, Illinois; Sainte Genevieve County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 24, 2011, 2:47 PM CDT for Randolph County, Illinois; Sainte Genevieve County, Missouri. It was in force for 43 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
Jul 24, 2011, 2:47 PM CDT (19:47 UTC)
Expired
Jul 24, 2011, 3:30 PM CDT
In force
43 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Randolph County, IL, Sainte Genevieve County, MO

The radar

The St Louis radar (KLSX), 111 km from the middle of the area, began a volume at 19:49 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 nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 7.8 hours before the alert went out and 270 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-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2011-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3589 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2011-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
3589 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
977 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
25 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.

284 
WUUS53 KLSX 241947
SVRLSX
ILC157-MOC186-242030-
/O.NEW.KLSX.SV.W.0470.110724T1947Z-110724T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
247 PM CDT SUN JUL 24 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN RANDOLPH COUNTY IN SOUTHWEST ILLINOIS...
  NORTHERN STE. GENEVIEVE COUNTY IN SOUTHEAST MISSOURI...

* UNTIL 330 PM CDT

* AT 245 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR BLOOMSDALE...OR 9 MILES
  NORTHWEST OF STE. GENEVIEVE...AND MOVING SOUTHEAST AT 10 MPH.
  ALSO...ANOTHER SEVERE THUNDERSTORM WAS LOCATED 5 MILES SOUTHWEST OF
  EVANSVILLE...AND MOVING SOUTHEAST AT 10 MPH. PENNY SIZE HAIL MAY
  ALSO ACCOMPANY THESE DAMAGING WINDS.

* LOCATIONS IMPACTED INCLUDE...
  STE. GENEVIEVE...CHESTER...ROCKY RIDGE...ST. MARY...EVANSVILLE...
  BREMEN...PRAIRIE DU ROCHER...RUMA...MODOC...KELLOGG...ROOTS...RIVER
  AUX VASES...KASKASKIA...ELLIS GROVE...NEW PALESTINE...WELGE AND
  ROCKWOOD.

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 3780 8968 3784 8974 3785 8979 3788 8981
      3790 8985 3787 8990 3787 8994 3780 9002
      3800 9035 3812 9009 3813 9004 3815 9003
      3796 8959 3795 8959
TIME...MOT...LOC 1946Z 302DEG 9KT 3803 9019
WIND...HAIL 60MPH 0.75IN

$$

BYRD
2 follow-up statements
228 
WWUS53 KLSX 242010
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
310 PM CDT SUN JUL 24 2011

ILC157-MOC186-242030-
/O.CON.KLSX.SV.W.0470.000000T0000Z-110724T2030Z/
RANDOLPH IL-STE. GENEVIEVE MO-
310 PM CDT SUN JUL 24 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN STE.
GENEVIEVE AND SOUTHERN RANDOLPH COUNTIES UNTIL 330 PM CDT...

AT 307 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF
60 MPH.  THIS STORM WAS LOCATED NEAR BLOOMSDALE...OR 5 MILES WEST OF
STE. GENEVIEVE...MOVING SOUTHEAST AT 10 MPH. PENNY SIZE HAIL MAY ALSO
ACCOMPANY THESE DAMAGING WINDS.

LOCATIONS IMPACTED INCLUDE...
  STE. GENEVIEVE...CHESTER...ST. MARY...EVANSVILLE...BREMEN...
  MODOC...KELLOGG...RIVER AUX VASES...ROOTS...KASKASKIA...ELLIS
  GROVE...NEW PALESTINE...WELGE AND ROCKWOOD.

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 3780 8968 3784 8974 3785 8979 3788 8981
      3790 8985 3787 8990 3787 8994 3780 9002
      3798 9032 3813 8997 3796 8959 3795 8959
TIME...MOT...LOC 2008Z 304DEG 9KT 3800 9014
WIND...HAIL 60MPH 0.75IN

$$

BYRD
359 
WWUS53 KLSX 242029
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
329 PM CDT SUN JUL 24 2011

ILC157-MOC186-242039-
/O.EXP.KLSX.SV.W.0470.000000T0000Z-110724T2030Z/
RANDOLPH IL-STE. GENEVIEVE MO-
329 PM CDT SUN JUL 24 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN STE. GENEVIEVE AND
SOUTHERN RANDOLPH COUNTIES WILL EXPIRE AT 330 PM CDT...

THE STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
HOWEVER HEAVY RAIN IS STILL POSSIBLE WITH THESE THUNDERSTORMS.

LAT...LON 3780 8968 3784 8974 3785 8979 3788 8981
      3790 8985 3787 8990 3787 8994 3780 9002
      3798 9032 3813 8997 3796 8959 3795 8959
TIME...MOT...LOC 2029Z 304DEG 9KT 3797 9008

$$

BYRD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 12:21 PM CDTSevere Thunderstorm WarningLSXFayette, Montgomery24 min
Jul 24, 1:50 PM CDTSevere Thunderstorm WarningLSXMarion25 min
Jul 24, 3:09 PM CDTFlash Flood WarningLSXRandolph5 hr
Jul 24, 4:00 PM CDTExcessive Heat WatchLSXAdams, Bond, Brown, Clinton, Fayette, Greene and 5 more24 hr
Jul 24, 3:44 PM CDTSevere Thunderstorm WarningLSXSainte Genevieve, Saint Francois46 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2011Severe Thunderstorm Warnings in Missouri, 2011Every 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.