Alert archive / Illinois / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 425, NWS St. Louis, MO

July 3, 2011Randolph County, Saint Clair County, Washington County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 3, 2011, 1:31 PM CDT for Randolph County, Saint Clair County, Washington County, Illinois. It was in force for 44 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 3, 2011, 1:31 PM CDT (18:31 UTC)
Expired: Jul 3, 2011, 2:15 PM CDT
In force: 44 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Randolph County, IL, Saint Clair County, IL, Washington County, IL

The radar

The St Louis radar (KLSX), 93 km from the middle of the area, began a volume at 18:33 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 3, 1:40 PM CDT	HAIL 1.25	New Athens, IL
Jul 3, 1:49 PM CDT	HAIL 0.88	New Athens, 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
Jul 3, 1:15 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 6.5 hours before the alert went out and 234 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: 1911 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 884 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -10 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.1

Open this sounding in Storm Lab

The text

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

473 
WUUS53 KLSX 031831
SVRLSX
ILC157-163-189-031915-
/O.NEW.KLSX.SV.W.0425.110703T1831Z-110703T1915Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
131 PM CDT SUN JUL 3 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN RANDOLPH COUNTY IN SOUTHWEST ILLINOIS...
  SOUTHEASTERN ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS...
  SOUTHWESTERN WASHINGTON COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 215 PM CDT

* AT 129 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PING PONG BALL SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
  LOCATED NEAR MARISSA...OR 9 MILES NORTHWEST OF SPARTA...AND MOVING
  EAST AT 10 MPH.

* LOCATIONS IMPACTED INCLUDE...
  MARISSA...TILDEN...LIVELY GROVE...COULTERVILLE...ST. LIBORY...STONE
  CHURCH...ELKTON AND JOHANNISBURG.

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 3821 8959 3814 8959 3818 8992 3822 8993
      3822 8990 3828 8992 3828 8990 3831 8991
      3831 8993 3835 8994 3840 8952 3821 8950
TIME...MOT...LOC 1832Z 268DEG 8KT 3827 8979
WIND...HAIL 60MPH 1.50IN

$$

CARNEY

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 3, 2:39 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Monroe, Randolph, Saint Clair, Washington	21 min
Jul 3, 2:50 PM CDT	Severe Thunderstorm Warning	LSX	Monroe, Saint Clair	40 min
Jul 3, 3:00 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Monroe, Randolph, Saint Clair, Washington	45 min
Jul 3, 3:24 PM CDT	Areal Flood Advisory	LSX	Clinton, Marion, Monroe, Randolph, Saint Clair, Washington	6 hr
Jul 3, 3:45 PM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton	30 min
Jul 3, 3:56 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Jersey	49 min

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.