Alert archive / Illinois / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 459, NWS St. Louis, MO

September 12, 2000Monroe County, Saint Clair County, Illinois; Jefferson County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Sep 12, 2000, 12:01 AM CDT for Monroe County, Saint Clair County, Illinois; Jefferson County, Missouri. It was in force for 59 min. 2 reports came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: Sep 12, 2000, 12:01 AM CDT (05:01 UTC)
Expired: Sep 12, 2000, 1:00 AM CDT
In force: 59 min
Issued by: NWS St. Louis, MO
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Monroe County, IL, Saint Clair County, IL, Jefferson County, MO

The radar

The St Louis radar (KLSX), 52 km from the middle of the area, began a volume at 05:03 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
Sep 12, 12:10 AM CDT	Thunderstorm Wind 56 E	Imperial, MO
Sep 12, 12:10 AM CDT	Thunderstorm Wind 56 E	Hillsboro, MO

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

Issued	Product	Office	Lasted
Sep 11, 10:30 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 5.0 hours before the alert went out and 237 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: 3019 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1421 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 140 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 5.6

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KLSX 120503
SVRSTL
ILC133-163-MOC099-120600-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1201 AM CDT TUE SEP 12 2000

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  JEFFERSON COUNTY IN EAST CENTRAL MISSOURI
  MONROE COUNTY IN SOUTHWEST ILLINOIS
  ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS

* UNTIL 100 AM CDT

* AT 1201 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM O'FALLON ILLINOIS TO 7 MILES WEST
  OF HILLSBORO MISSOURI...MOVING SOUTHEAST AT 35 MPH.

* LOCATIONS IN THE PATH...
  BELLEVILLE
  FOUNTAIN
  O'FALLON
  SWANSEA
  MILLSTADT
  SHILOH
  VALMEYER
  HERCULANEUM
  CRYSTAL CITY
  DE SOTO

THIS STORM HAS A HISTORY OF DAMAGING WINDS. TAKE SHELTER IN A STURDY
BUILDING IMMEDIATELY.

LAT...LON 3868 8999 3832 9078 3803 9059 3835 8967

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 9:10 PM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown	65 min
Sep 11, 9:32 PM CDT	Severe Thunderstorm Warning	LSX	Pike	58 min
Sep 11, 10:09 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun	66 min
Sep 11, 10:32 PM CDT	Severe Thunderstorm Warning	LSX	Greene	58 min
Sep 11, 10:51 PM CDT	Severe Thunderstorm Warning	LSX	Jersey	39 min
Sep 11, 10:53 PM CDT	Severe Thunderstorm Warning	LSX	Macoupin	52 min
Sep 11, 11:16 PM CDT	Severe Thunderstorm Warning	LSX	Madison	59 min
Sep 11, 7:53 PM CDT	Severe Thunderstorm Warning	LSX	Knox	52 min
Sep 11, 9:10 PM CDT	Severe Thunderstorm Warning	LSX	Boone	50 min
Sep 11, 9:32 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Pike, Ralls	58 min
Sep 11, 9:47 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Montgomery	43 min
Sep 11, 10:09 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Warren	66 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2000 Severe Thunderstorm Warnings in Missouri, 2000 Every severe thunderstorm warning in 2000

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.