Alert archive / Illinois / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 23, NWS St. Louis, MO

February 11, 1999Adams County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Feb 11, 1999, 12:22 PM CST for Adams County, Illinois. It was in force for 48 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Feb 11, 1999, 12:22 PM CST (18:22 UTC)
Expired
Feb 11, 1999, 1:10 PM CST
In force
48 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Adams County, IL

The radar

The St Louis radar (KLSX), 150 km from the middle of the area, began a volume at 18:25 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.

IssuedProductOfficeLasted
Feb 11, 11:15 AM CSTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 6.4 hours before the alert went out and 190 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-pSkew-T log-p diagram, Davenport, at 12:00Z on 1999-02-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 263 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 1999-02-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 395 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
263 J/kg
Mixed-layer CIN
-346 J/kg
Mixed-layer LCL
653 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
395 m²/s²
0-3 km storm-relative helicity
310 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Feb 11, 10:25 AM CST, 1 hour 57 minutes before
ILZ058>060-064-065-069-070-074-079-095>102-MOZ009-010-018-019-026-
027-034>036-041-042-047>052-059>065-072>075-084-085-099-112300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1025 AM CST THU FEB 11 1999

THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NWS OFFICE IN
ST LOUIS.  AREAS INCLUDED ARE PARTS OF CENTRAL...NORTHEAST AND EAST
CENTRAL MISSOURI...AND SOUTHWEST ILLINOIS.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
THROUGH EARLY THIS EVENING ACROSS THE ENTIRE REGION.  THIS INCLUDES
THE LARGER CITIES OF ST LOUIS...COLUMBIA...JEFFERSON CITY...
HANNIBAL...FARMINGTON...STE GENEVIEVE...QUINCY IL...VANDALIA IL...AND
CENTRALIA IL.

A LINE OF STRONG TO SEVERE THUNDERSTORMS IS EXPECTED TO PUSH
WEST TO EAST ACROSS THE AREA.  THE MAIN SEVERE WEATHER THREAT
WITH THIS LINE OF STORMS WILL BE DAMAGING WIND GUSTS IN EXCESS
OF 60 MPH.  THE THREAT OVER CENTRAL MISSOURI SHOULD BE EARLY
THIS AFTERNOON...OVER EASTERN MISSOURI AROUND MIDDLE AFTERNOON...
AND OVER WESTERN ILLINOIS DURING THE LATE AFTERNOON AND EARLY
EVENING.

STORM SPOTTER GROUPS AND EMERGENCY MANAGERS SHOULD KEEP ADVISED OF
THE LATEST FORECASTS...AND MONITOR WEATHER INFORMATION FOR POSSIhBLE
SKYWARN ACTION.

GLASS

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 11, 11:10 AM CSTSevere Thunderstorm WarningLSXKnox, Scotland50 min
Feb 11, 11:28 AM CSTSevere Thunderstorm WarningLSXClark47 min
Feb 11, 11:31 AM CSTSevere Thunderstorm WarningLSXMonroe, Shelby64 min
Feb 11, 11:54 AM CSTSevere Thunderstorm WarningLSXLewis46 min
Feb 11, 12:02 PM CSTSevere Thunderstorm WarningLSXMarion48 min
Feb 11, 12:04 PM CSTSevere Thunderstorm WarningLSXBoone51 min
Feb 11, 12:25 PM CSTSevere Thunderstorm WarningLSXAudrain, Callaway50 min
Feb 11, 12:46 PM CSTSevere Thunderstorm WarningLSXOsage49 min
Feb 11, 1:12 PM CSTSevere Thunderstorm WarningLSXGasconade48 min
Feb 11, 1:26 PM CSTSevere Thunderstorm WarningLSXFranklin49 min
Feb 11, 1:35 PM CSTSevere Thunderstorm WarningLSXFranklin, Warren50 min
Feb 11, 1:48 PM CSTTornado WarningLSXLincoln47 min
Feb 11, 1:56 PM CSTTornado WarningLSXPike49 min
Feb 11, 2:47 PM CSTSevere Thunderstorm WarningLSXSaint Louis, City of Saint Louis48 min
Feb 11, 1:54 PM CSTTornado WarningLSXBrown46 min
Feb 11, 2:09 PM CSTTornado WarningLSXGreene51 min
Feb 11, 2:12 PM CSTTornado WarningLSXPike48 min
Feb 11, 4:24 PM CSTSevere Thunderstorm WarningLSXFayette51 min
Feb 11, 4:37 PM CSTSevere Thunderstorm WarningLSXMarion48 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1999Every severe thunderstorm warning in 1999

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.