Alert archive / Illinois / Tornado Watches in 1998

Tornado Watch 174

April 7, 199828 counties in Illinois; 19 counties in Indiana

The Storm Prediction Center issued this tornado watch at Apr 7, 1998, 4:15 PM CDT for 28 counties in Illinois; 19 counties in Indiana. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 7, 1998, 4:15 PM CDT (21:15 UTC)
Expired
Apr 7, 1998, 10:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 47 counties

Bond County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Hamilton County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Lawrence County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Montgomery County, IL, Perry County, IL, Richland County, IL, Shelby County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Clay County, IN, Crawford County, IN, Daviess County, IN, Dubois County, IN, Gibson County, IN, Greene County, IN, Knox County, IN, Martin County, IN, Orange County, IN, Owen County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Putnam County, IN, Spencer County, IN, Sullivan County, IN, Vanderburgh County, IN, Vigo County, IN, Warrick County, IN

Warnings issued inside it

19 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 7, 4:34 PM CDTSevere Thunderstorm WarningLSXMacoupin41 min
Apr 7, 4:44 PM CDTTornado WarningLSXMacoupin46 min
Apr 7, 5:08 PM CDTSevere Thunderstorm WarningLSXMontgomery37 min
Apr 7, 6:06 PM CDTTornado WarningILXMacon, Shelby69 min
Apr 7, 6:39 PM CDTTornado WarningINDHendricks, Putnam51 min
Apr 7, 7:03 PM CDTTornado WarningILXColes, Douglas57 min
Apr 7, 7:39 PM CDTTornado WarningILXEdgar51 min
Apr 7, 8:00 PM CDTSevere Thunderstorm WarningPAHFranklin30 min
Apr 7, 8:16 PM CDTSevere Thunderstorm WarningPAHHamilton44 min
Apr 7, 8:28 PM CDTTornado WarningILXEdgar62 min
Apr 7, 8:36 PM CDTTornado WarningILXEffingham54 min
Apr 7, 8:48 PM CDTTornado WarningLSXFayette, Marion42 min
Apr 7, 8:54 PM CDTSevere Thunderstorm WarningLSXClinton51 min
Apr 7, 9:11 PM CDTTornado WarningILXJasper64 min
Apr 7, 9:19 PM CDTTornado WarningPAHGibson31 min
Apr 7, 9:30 PM CDTTornado WarningILXClay, Effingham60 min
Apr 7, 9:30 PM CDTTornado WarningLMKDubois30 min
Apr 7, 9:41 PM CDTTornado WarningPAHPike49 min
Apr 7, 9:58 PM CDTTornado WarningLMKOrange32 min

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.3 hours before the alert went out and 141 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, Lincoln, IL at 12:00Z on 1998-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Lincoln, IL at 12:00Z on 1998-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 69 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1568 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
69 m²/s²
0-3 km storm-relative helicity
51 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.

373 
WWUS9 KMKC 072044
SEL4  
MKC WW 072044
ILZ000-INZ000-080300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 174
STORM PREDICTION CENTER NORMAN OK
344 PM CDT TUE APR 7 1998

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   CENTRAL AND SOUTHERN ILLINOIS                           
   SOUTHWEST INDIANA                            

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 415 PM UNTIL 1000
PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 60 STATUTE MILES EITHER SIDE OF
A LINE FROM SCOTT AFB BELLEVILLE ILLINOIS TO 15 MILES SOUTH
SOUTHEAST OF BLOOMINGTON INDIANA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...  CONTINUE...WW 173...

DISCUSSION...AIRMASS NOW MODERATELY UNSTABLE S OF WARM FRONT ACROSS
IL INTO SWRN IN.  WARM DEEPLY MIXED AIRMASS MOVING ACROSS EASTERN
MO WILL ENHANCE SEVERE THUNDERSTORM DEVELOPMENT ACROSS SRN IL. 
VEERING WIND PROFILES WITH STRONG MID/UPPER JET FAVOR SUPERCELLS
AND ISOLATED TORNADOS. 


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 24035.


...HALES

392,0900 394,0864 380,0862 374,0894

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 7, 2:00 PM CDTTornado WatchSPCAdams, Brown, Cass, Christian, DeWitt, Fulton and 24 more6 hr

Nearby

Tornado Watches in Illinois, 1998Tornado Watches in Indiana, 1998Every tornado watch 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; the sounding from the Mesonet's radiosonde archive.