Alert archive / Illinois / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 260, NWS St. Louis, MO

June 20, 1998Clinton County, Washington County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 20, 1998, 1:32 AM CDT for Clinton County, Washington County, Illinois. It was in force for 48 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jun 20, 1998, 1:32 AM CDT (06:32 UTC)
Expired: Jun 20, 1998, 2:20 AM CDT
In force: 48 min
Issued by: NWS St. Louis, MO
Area: Whole counties

Counties Clinton County, IL, Washington County, IL

The radar

The St Louis radar (KLSX), 113 km from the middle of the area, began a volume at 06:33 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
Jun 20, 2:00 AM CDT	Thunderstorm Wind 55	Venedy Station, IL
Jun 20, 2:00 AM CDT	Thunderstorm Wind 55	New Memphis, IL

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 nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 6.5 hours before the alert went out and 199 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: 2156 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: 99 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.

526 
WUUS1 KSTL 200631 RRA
SVRSTL
ILC027-189-200720-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
132 AM CDT SAT JUN 20 1998

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CLINTON COUNTY IN SOUTHWESTERN ILLINOIS
  WASHINGTON COUNTY ILLINOIS IN SOUTHWESTERN ILLINOIS

* UNTIL 220 AM CDT

* AT 130 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS MARRISA TO 10 MILES EAST OF
  FREEBURG...MOVING EAST AT 40 MPH.

* LOCATIONS THAT WILL BE AFFECTED...
  LIVELY GROVE
  NASHVILLE
  OKAWVILLE
  ALBERS
  GERMANTOWN



THE PRIMARY SEVERE WEATHER THREAT IS DAMAGING WINDS. MOVE QUICKLY
TO A STURDY BUILDING AND STAY AWAY FROM DOORS AND WINDOWS.



FG/DM

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 12:44 AM CDT	Severe Thunderstorm Warning	LSX	Monroe, Saint Clair	66 min
Jun 20, 1:24 AM CDT	Severe Thunderstorm Warning	LSX	Randolph	46 min
Jun 20, 3:34 AM CDT	Severe Thunderstorm Warning	LSX	Monroe	51 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1998 Every severe thunderstorm warning in 1998

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.