Alert archive / Illinois / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 113, NWS St. Louis, MO

April 19, 2011Fayette County, Montgomery County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 19, 2011, 7:35 PM CDT for Fayette County, Montgomery County, Illinois. It was in force for 40 min. 1 report 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: Apr 19, 2011, 7:35 PM CDT (00:35 UTC)
Expired: Apr 19, 2011, 8:15 PM CDT
In force: 40 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.5 in
Wind: 70.0 mph

Counties Fayette County, IL, Montgomery County, IL

The radar

The Lincoln radar (KILX), 113 km from the middle of the area, began a volume at 00:36 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
Apr 19, 7:52 PM CDT	HAIL 0.25	Ramsey, IL

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
Apr 19, 1:00 PM CDT	Tornado Watch	SPC	10 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.6 hours before the alert went out and 120 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: 2409 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 523 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 370 m²/s²
0-3 km storm-relative helicity: 547 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 24.4

Open this sounding in Storm Lab

The text

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

581 
WUUS53 KLSX 200035
SVRLSX
ILC051-135-200115-
/O.NEW.KLSX.SV.W.0113.110420T0035Z-110420T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
735 PM CDT TUE APR 19 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN FAYETTE COUNTY IN SOUTH CENTRAL ILLINOIS...
  NORTHEASTERN MONTGOMERY COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 815 PM CDT

* AT 732 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A SEVERE
  THUNDERSTORM PRODUCING PING PONG BALL SIZE HAIL...AND DESTRUCTIVE
  WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR WOBURN...OR
  9 MILES NORTH OF GREENVILLE...AND MOVING NORTHEAST AT 55 MPH.

* LOCATIONS IMPACTED INCLUDE...
  VANDALIA...RAMSEY...BROWNSTOWN...ST. ELMO...WRIGHTS CORNER...
  HAGERSTOWN...SHAFTER...BINGHAM...BAYLE CITY...OHLMAN AND AVENA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

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 3890 8927 3901 8927 3902 8926 3903 8927
      3935 8926 3936 8921 3936 8914 3935 8913
      3922 8913 3922 8881 3921 8880 3900 8881
TIME...MOT...LOC 0035Z 243DEG 50KT 3904 8932
WIND...HAIL 70MPH 1.50IN

$$

TILLY

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 19, 7:30 PM CDT	Tornado Warning	LSX	Madison, Saint Clair	45 min
Apr 19, 7:34 PM CDT	Tornado Warning	LSX	Randolph	41 min
Apr 19, 7:37 PM CDT	Tornado Warning	LSX	Monroe	36 min
Apr 19, 7:51 PM CDT	Tornado Warning	LSX	Saint Clair	39 min
Apr 19, 7:54 PM CDT	Tornado Warning	LSX	Randolph	36 min
Apr 19, 7:56 PM CDT	Severe Thunderstorm Warning	LSX	Bond, Montgomery	34 min
Apr 19, 8:00 PM CDT	Tornado Warning	LSX	Bond, Clinton, Madison	45 min
Apr 19, 8:02 PM CDT	Areal Flood Advisory	LSX	Bond, Macoupin, Montgomery	4 hr
Apr 19, 8:18 PM CDT	Tornado Warning	LSX	Randolph, Saint Clair, Washington	42 min
Apr 19, 8:25 PM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton, Madison, Saint Clair	22 min
Apr 19, 8:33 PM CDT	Tornado Warning	LSX	Fayette	42 min
Apr 19, 8:33 PM CDT	Tornado Warning	LSX	Bond, Clinton, Fayette, Marion, Washington	57 min
Apr 19, 9:37 PM CDT	Severe Thunderstorm Warning	LSX	Madison	21 min
Apr 19, 9:41 PM CDT	River Flood Warning	LSX	Fayette	13 days

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