Alert archive / Illinois / Tornado Watches in 1998

Tornado Watch 221

April 15, 19984 states

The Storm Prediction Center issued this tornado watch at Apr 15, 1998, 11:00 PM CDT for 4 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 15, 1998, 11:00 PM CDT (04:00 UTC)
Expired
Apr 16, 1998, 4:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 38 counties

Alexander County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Massac County, IL, Monroe County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saline County, IL, Union County, IL, White County, IL, Williamson County, IL, Gibson County, IN, Posey County, IN, Ballard County, KY, Carlisle County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Perry County, MO, Ripley County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 88 km from the middle of the area, began a volume at 03:59 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 15, 11:03 PM CDTSevere Thunderstorm WarningPAHGibson27 min
Apr 15, 11:10 PM CDTTornado WarningPAHFranklin50 min
Apr 15, 11:15 PM CDTFlash Flood WarningPAHEdwards, Wabash, White4 hr
Apr 15, 11:15 PM CDTFlash Flood WarningPAHHamilton4 hr
Apr 15, 11:30 PM CDTFlash Flood WarningPAHPerry3 hr
Apr 15, 11:30 PM CDTFlash Flood WarningPAHBollinger, Perry3 hr
Apr 15, 11:31 PM CDTFlash Flood WarningPAHGibson3 hr
Apr 15, 11:46 PM CDTFlash Flood WarningPAHJackson3 hr
Apr 15, 11:55 PM CDTTornado WarningPAHUnion40 min
Apr 15, 11:55 PM CDTTornado WarningPAHCape Girardeau35 min
Apr 16, 12:17 AM CDTFlash Flood WarningPAHCape Girardeau3 hr
Apr 16, 12:30 AM CDTFlash Flood WarningPAHPosey, Vanderburgh3 hr
Apr 16, 1:14 AM CDTFlash Flood WarningPAHFranklin, Williamson4 hr
Apr 16, 2:55 AM CDTFlash Flood WarningPAHGibson, Posey, Vanderburgh3 hr

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 4.0 hours before the alert went out and 272 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, Little Rock, AR at 00:00Z on 1998-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1219 joules per kilogram.LCLEL10008507005003002001001 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, Little Rock, AR at 00:00Z on 1998-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 100 square meters per square second.1939587897117136156Sfc1 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
1219 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
868 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
100 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.7
Supercell composite
2.7

Open this sounding in Storm Lab

The text

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

288 
WWUS9 KMKC 160320
SEL1  
MKC WW 160320
ILZ000-MOZ000-KYZ000-160900-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 221
STORM PREDICTION CENTER NORMAN OK
1020 PM CDT WED APR 15 1998

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

   SOUTHERN ILLINOIS                           
   SOUTHEAST MISSOURI                          
   EXTREME WESTERN KENTUCKY                           

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1100 PM
UNTIL 400 AM 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 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 35 MILES EAST SOUTHEAST OF POPLAR BLUFF MISSOURI TO
MOUNT VERNON ILLINOIS.

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...THIS TORNADO WATCH REPLACES TORNADO WATCH
NUMBER 216...TORNADO WATCH NUMBER 218.  WATCH NUMBER 216...218 WILL
NOT BE IN EFFECT AFTER 1100 PM CDT.  CONTINUE...WW 217...WW
219...WW 2Y...

DISCUSSION...LINE OF SEVERE THUNDERSTORMS FROM SOUTHERN ILLINOIS
INTO SOUTHEAST MISSOURI IS EXPECTED TO CONTINUE MOVING EASTWARD
DURING THE EARLY MORNING HOURS AS NOSE OF STRONG MID/UPPER LEVEL
JET PROGRESSES TOWARD THE MISSISSIPPI VALLEY.  VAD DATA INDICATE
THAT LOW LEVEL JET HAS STRENGTHENED WITH 50-60 KT SOUTHERLY WINDS
NOW EVIDENT.  WINDS VEER WITH HEIGHT CREATING LARGE SHEAR AND
HELICITY SUPPORTIVE OF CONTINUED TORNADIC SUPERCELL THREAT.


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 450. 
MEAN STORM MOTION VECTOR 24050.


...WEISS

363,0910 381,0900 381,0873 363,0883

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 15, 7:00 PM CDTTornado WatchSPCMadison, Monroe, Saint Clair4 hr
Apr 15, 8:45 PM CDTTornado WatchSPCCrawford, Lawrence, Wabash5 hr
Apr 15, 10:15 PM CDTTornado WatchSPCOhio, Switzerland6 hr
Apr 16, 1:45 AM CDTTornado WatchSPCBartholomew, Clark, Crawford, Dearborn, Decatur, Dubois and 15 more5 hr
Apr 16, 12:30 PM CDTSevere Thunderstorm WatchSPCAdams, Allen, DeKalb, Elkhart, Huntington, Kosciusko and 7 more
Apr 16, 1:45 PM CDTTornado WatchSPCBartholomew, Blackford, Brown, Clark, Crawford, Dearborn and 33 more6 hr
Apr 16, 7:00 AM CDTTornado WatchSPCAdair, Bell, Boyle, Breathitt, Casey, Clay and 21 more6 hr
Apr 16, 4:00 PM CDTTornado WatchSPCCalloway6 hr
Apr 16, 4:30 PM CDTTornado WatchSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 47 more7 hr
Apr 16, 12:00 AM CDTTornado WatchSPCDunklin, Pemiscot5 hr
Apr 16, 7:30 AM CDTSevere Thunderstorm WatchSPCDunklin, Pemiscot6 hr

Nearby

Tornado Watches in Illinois, 1998Tornado Watches in Missouri, 1998Tornado Watches in Kentucky, 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; radar from the NEXRAD Level II archive.