Alert archive / Illinois / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 321, NWS St. Louis, MO

June 15, 20115 counties in Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 15, 2011, 3:46 AM CDT for 5 counties in Illinois. It was in force for 44 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: Jun 15, 2011, 3:46 AM CDT (08:46 UTC)
Expired: Jun 15, 2011, 4:30 AM CDT
In force: 44 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 0.88 in
Wind: 70.0 mph

Counties Calhoun County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL

The radar

The St Louis radar (KLSX), 45 km from the middle of the area, began a volume at 08:47 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 00:00Z, 8.8 hours before the alert went out and 196 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: 2 J/kg
Mixed-layer CIN: -693 J/kg
Mixed-layer LCL: 838 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 168 m²/s²
0-3 km storm-relative helicity: 325 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.

989 
WUUS53 KLSX 150846
SVRLSX
ILC013-061-083-117-119-150930-
/O.NEW.KLSX.SV.W.0321.110615T0846Z-110615T0930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
346 AM CDT WED JUN 15 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CALHOUN COUNTY IN SOUTHWEST ILLINOIS...
  SOUTHERN GREENE COUNTY IN SOUTHWEST ILLINOIS...
  JERSEY COUNTY IN SOUTHWEST ILLINOIS...
  SOUTHERN MACOUPIN COUNTY IN SOUTHWEST ILLINOIS...
  NORTHWESTERN MADISON COUNTY IN SOUTHWEST ILLINOIS...

* UNTIL 430 AM CDT

* AT 342 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DESTRUCTIVE WINDS
  IN EXCESS OF 70 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
  EXTENDING FROM 8 MILES NORTHEAST OF ST. PAUL TO FLORISSANT...AND
  MOVING NORTHEAST AT 40 MPH. NICKEL SIZE HAIL MAY ALSO ACCOMPANY
  THESE DAMAGING WINDS.

* LOCATIONS IMPACTED INCLUDE...
  ALTON...BETHALTO...GODFREY...JERSEYVILLE...GILLESPIE...GRAFTON...
  ELSAH...HARDIN...DORSEY...BRIGHTON...PRAIRIETOWN...OLD KANE...
  BUNKER HILL...SHIPMAN...WILSONVILLE...KEMPER...BENLD...BRUSSELS...
  DEER PLAIN AND BATCHTOWN.

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 3885 9011 3892 9026 3892 9029 3897 9042
      3896 9047 3890 9050 3889 9053 3890 9063
      3906 9070 3911 9068 3915 9071 3929 9015
      3916 8970 3909 8970
TIME...MOT...LOC 0846Z 231DEG 33KT 3893 9058 3885 9026
WIND...HAIL 70MPH 0.88IN

$$

TILLY

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 15, 12:07 AM CDT	Flash Flood Warning	LSX	Adams	8 hr
Jun 15, 3:29 AM CDT	Severe Thunderstorm Warning	LSX	Calhoun	46 min
Jun 15, 3:45 AM CDT	Areal Flood Advisory	LSX	Calhoun	3 hr
Jun 15, 4:02 AM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Greene	43 min
Jun 15, 4:15 AM CDT	Severe Thunderstorm Warning	LSX	Macoupin, Montgomery	48 min
Jun 15, 6:56 AM CDT	Areal Flood Warning	LSX	Adams	12 hr

Nearby

Severe Thunderstorm Warnings in Illinois, 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.