Alert archive / Illinois / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 458, NWS St. Louis, MO

July 12, 2011Marion County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 12, 2011, 4:18 PM CDT for Marion County, Illinois. It was in force for 27 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 12, 2011, 4:18 PM CDT (21:18 UTC)
Expired: Jul 12, 2011, 4:45 PM CDT
In force: 27 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Marion County, IL

The radar

The Evansville,IN radar (KVWX), 100 km from the middle of the area, began a volume at 21:20 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
Jul 12, 1:45 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.3 hours before the alert went out and 162 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: 1615 J/kg
Mixed-layer CIN: -167 J/kg
Mixed-layer LCL: 777 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: -14 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

159 
WUUS53 KLSX 122118
SVRLSX
ILC121-122145-
/O.NEW.KLSX.SV.W.0458.110712T2118Z-110712T2145Z/

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

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL MARION COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 445 PM CDT

* AT 416 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
  STEPHEN FORBES STATE PARK...OR 13 MILES EAST OF SALEM...AND MOVING
  NORTHEAST AT 5 MPH.

* LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF EASTERN MARION COUNTY.

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.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN ST LOUIS.

&&

LAT...LON 3864 8877 3874 8882 3878 8869 3877 8869
      3865 8869 3865 8870
TIME...MOT...LOC 2118Z 243DEG 5KT 3870 8873
WIND...HAIL 60MPH 1.00IN

$$

TES

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 2:25 PM CDT	Severe Thunderstorm Warning	LSX	Madison, Saint Clair	26 min
Jul 12, 2:31 PM CDT	Flash Flood Warning	LSX	Madison, Saint Clair	3 hr
Jul 12, 3:20 PM CDT	Areal Flood Advisory	LSX	Adams	102 min
Jul 12, 3:23 PM CDT	Areal Flood Advisory	LSX	Marion, Washington	3 hr
Jul 12, 3:38 PM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown	52 min
Jul 12, 3:44 PM CDT	Severe Thunderstorm Warning	LSX	Adams, Pike	46 min
Jul 12, 4:06 PM CDT	Flash Flood Warning	LSX	Marion	3 hr
Jul 12, 4:31 PM CDT	Severe Thunderstorm Warning	LSX	Brown, Calhoun, Greene, Jersey, Pike	44 min
Jul 12, 4:44 PM CDT	Tornado Warning	LSX	Greene, Macoupin, Pike	46 min
Jul 12, 4:48 PM CDT	Severe Thunderstorm Warning	LSX	Marion	42 min
Jul 12, 5:03 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Greene, Jersey, Macoupin, Madison, Montgomery and 1 more	57 min
Jul 12, 5:10 PM CDT	Severe Thunderstorm Warning	LSX	Fayette, Montgomery	30 min
Jul 12, 5:51 PM CDT	Severe Thunderstorm Warning	LSX	Bond, Fayette, Marion	39 min
Jul 12, 6:53 PM CDT	Areal Flood Warning	LSX	Marion	4 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.