Alert archive / Illinois / Severe Thunderstorm Warnings in 2005

Severe Thunderstorm Warning 49, NWS St. Louis, MO

April 21, 2005Monroe County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 21, 2005, 7:44 PM CDT for Monroe County, Saint Clair County, Illinois. It was in force for 46 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: Apr 21, 2005, 7:44 PM CDT (00:44 UTC)
Expired: Apr 21, 2005, 8:30 PM CDT
In force: 46 min
Issued by: NWS St. Louis, MO
Area: Counties, with a storm outline in the text

Counties Monroe County, IL, Saint Clair County, IL

The radar

The St Louis radar (KLSX), 52 km from the middle of the area, began a volume at 00:47 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 21, 6:45 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.7 hours before the alert went out and 233 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 513 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 205 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KLSX 220044
SVRLSX
ILC133-163-220130-
/O.NEW.KLSX.SV.W.0049.050422T0044Z-050422T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
744 PM CDT THU APR 21 2005

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN MONROE COUNTY IN SOUTHWEST ILLINOIS
  WESTERN ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS

* UNTIL 830 PM CDT

* AT 742 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DIME SIZE HAIL.  THIS
  STORM WAS LOCATED NEAR COLUMBIA...AND MOVING EAST AT 15 MPH.

* LOCATIONS IMPACTED INCLUDE...
  COLUMBIA
  DUPO
  WATERLOO
  CAHOKIA
  MILLSTADT
  SMITHTON

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

LAT...LON 3852 9027 3830 9037 3831 9004 3846 8993
      3860 9020

$$

CARNEY

2 follow-up statements

000 
WWUS53 KLSX 220113
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
812 PM CDT THU APR 21 2005

ILC133-220122-
/O.CAN.KLSX.SV.W.0049.000000T0000Z-050422T0130Z/
MONROE IL-
812 PM CDT THU APR 21 2005

...THE SEVERE THUNDERSTORM WARNING FOR MONROE COUNTY IS CANCELLED...

THE STORM HAS EXITED THIS AREA.

LAT...LON 3853 9028 3853 9027 3833 9003 3850 8972
      3865 8972 3867 9018

$$

ILC163-220130-
/O.CON.KLSX.SV.W.0049.000000T0000Z-050422T0130Z/
ST. CLAIR IL-
812 PM CDT THU APR 21 2005

...A SEVERE THUNDERSTORM WARNING CONTINUES UNTIL 830 PM CDT FOR ST.
CLAIR COUNTY...

AT 810 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DIME SIZE HAIL...
AND DAMAGING WINDS IN EXCESS OF 60 MPH OVER SHILOH...MOVING EAST AT 
25 MPH.  WINDS OF 55 TO 70 MPH WERE REPORTED IN THE SWANSEA AREA AT 
810 PM.

LOCATIONS NEAR THE PATH OF THE SEVERE THUNDERSTORM INCLUDE...
CENTREVILLE...SWANSEA...BELLEVILLE...FAIRVIEW HEIGHTS...SHILOH...
OFALLON...SCOTT AFB...LEBANON AND SUMMERFIELD.

THIS SEVERE THUNDERSTORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS
AND LARGE DAMAGING HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE
AND STAY AWAY FROM WINDOWS

LAT...LON 3853 9028 3853 9027 3833 9003 3850 8972
      3865 8972 3867 9018

$$

TRUETT/CARNEY

000 
WWUS53 KLSX 220130
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
830 PM CDT THU APR 21 2005

ILC163-220139-
/O.EXP.KLSX.SV.W.0049.000000T0000Z-050422T0130Z/
ST. CLAIR IL-
830 PM CDT THU APR 21 2005

...THE SEVERE THUNDERSTORM WARNING FOR ST. CLAIR COUNTY HAS
EXPIRED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND NO LONGER 
APPEARED TO BE SEVERE.  HOWEVER...WINDS OF 30 TO 40 MPH AND SMALL  
HAIL WILL STILL BE POSSIBLE IN NORTHEAST ST. CLAIR COUNTY...IN THE 
LEBANON AND SUMMERFIELD AREAS...THROUGH 9 PM.

LAT...LON 3853 9028 3853 9027 3833 9003 3850 8972
      3865 8972 3867 9018

$$

TRUETT/CARNEY

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 21, 7:29 PM CDT	Severe Thunderstorm Warning	LSX	Madison	48 min
Apr 21, 7:36 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Jersey	39 min
Apr 21, 8:05 PM CDT	Severe Thunderstorm Warning	LSX	Jersey, Macoupin	40 min
Apr 21, 8:40 PM CDT	Severe Thunderstorm Warning	LSX	Macoupin, Montgomery	50 min
Apr 22, 1:27 PM CDT	Severe Thunderstorm Warning	LSX	Washington	33 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2005 Every severe thunderstorm warning in 2005

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.