Alert archive / Illinois / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 201, NWS St. Louis, MO

July 18, 2003Calhoun County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 18, 2003, 8:59 AM CDT for Calhoun County, Illinois. It was in force for 31 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 18, 2003, 8:59 AM CDT (13:59 UTC)
Expired: Jul 18, 2003, 9:30 AM CDT
In force: 31 min
Issued by: NWS St. Louis, MO
Area: Counties, with a storm outline in the text

County Calhoun County, IL

The radar

The St Louis radar (KLSX), 52 km from the middle of the area, began a volume at 13:58 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 18, 4:30 AM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 2.0 hours before the alert went out and 206 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: 315 J/kg
Mixed-layer CIN: -200 J/kg
Mixed-layer LCL: 874 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 183 m²/s²
0-3 km storm-relative helicity: 243 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.2

Open this sounding in Storm Lab

The text

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

952 
WUUS53 KLSX 181359
SVRLSX
ILC013-181430-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
859 AM CDT FRI JUL 18 2003

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CALHOUN COUNTY IN SOUTHWEST ILLINOIS

* UNTIL 930 AM CDT

* AT 859 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 8 MILES NORTH OF HARDIN...MOVING SOUTHEAST AT
  35 MPH.

* LOCATIONS IMPACTED INCLUDE...
  HARDIN

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MPH...
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 3937 9062 3928 9077 3890 9066 3894 9050
          3912 9061

$$

TRUETT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 4:56 AM CDT	Severe Thunderstorm Warning	LSX	Brown	64 min
Jul 18, 5:29 AM CDT	Tornado Warning	LSX	Fayette, Montgomery	76 min
Jul 18, 5:56 AM CDT	Severe Thunderstorm Warning	LSX	Pike	49 min
Jul 18, 6:51 AM CDT	Severe Thunderstorm Warning	LSX	Macoupin	39 min
Jul 18, 6:56 AM CDT	Severe Thunderstorm Warning	LSX	Greene, Jersey	34 min
Jul 18, 7:11 AM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown	49 min
Jul 18, 7:20 AM CDT	Flash Flood Warning	LSX	Brown	4 hr
Jul 18, 7:22 AM CDT	Severe Thunderstorm Warning	LSX	Fayette	83 min
Jul 18, 7:31 AM CDT	Severe Thunderstorm Warning	LSX	Madison	59 min
Jul 18, 7:49 AM CDT	Severe Thunderstorm Warning	LSX	Brown, Pike	41 min
Jul 18, 8:22 AM CDT	Tornado Warning	LSX	Calhoun, Pike	38 min
Jul 18, 8:38 AM CDT	Severe Thunderstorm Warning	LSX	Greene	37 min
Jul 18, 8:50 AM CDT	Severe Thunderstorm Warning	LSX	Jersey, Macoupin	40 min
Jul 18, 9:14 AM CDT	Severe Thunderstorm Warning	LSX	Madison	46 min
Jul 18, 9:41 AM CDT	Severe Thunderstorm Warning	LSX	Monroe, Saint Clair	49 min
Jul 18, 10:02 AM CDT	Severe Thunderstorm Warning	LSX	Clinton, Washington	43 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2003 Every severe thunderstorm warning in 2003

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.