Alert archive / Illinois / Tornado Watches in 1998

Tornado Watch 397

May 22, 19984 states

The Storm Prediction Center issued this tornado watch at May 22, 1998, 5:30 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 22, 1998, 5:30 PM CDT (22:30 UTC)
Expired
May 22, 1998, 11:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 63 counties

Bond County, IL, Calhoun County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Cumberland County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Greene County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Johnson County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Pope County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Posey County, IN, Crittenden County, KY, Union County, KY, Audrain County, MO, Callaway County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Crawford County, MO, Dent County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Lincoln County, MO, Madison County, MO, Maries County, MO, Montgomery County, MO, Osage County, MO, Perry County, MO, Phelps County, MO, Pike County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 27 km from the middle of the area, began a volume at 22:34 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

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

IssuedProductOfficeCountiesLasted
May 22, 5:51 PM CDTSevere Thunderstorm WarningSGFPhelps19 min
May 22, 5:55 PM CDTSevere Thunderstorm WarningLSXCrawford50 min
May 22, 9:04 PM CDTSevere Thunderstorm WarningPAHPosey41 min
May 22, 10:25 PM CDTSevere Thunderstorm WarningLSXMontgomery30 min

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.5 hours before the alert went out and 231 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 1998-05-22Temperature 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 1998-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 square meters per square second.19395878Sfc1 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
733 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
165 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.

631 
WWUS9 KMKC 222204
SEL7  
MKC WW 222204
MOZ000-ILZ000-230400-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 397
STORM PREDICTION CENTER NORMAN OK
504 PM CDT FRI MAY 22 1998

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

   EASTERN MISSOURI                           
   SOUTHERN ILLINOIS                           

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 530 PM UNTIL 1100
PM CDT.

TORNADOES...HAIL TO 3 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 NORTH AND
SOUTH OF A LINE FROM 10 MILES SOUTH OF JEFFERSON CITY MISSOURI TO
60 MILES EAST OF 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...  CONTINUE...WW 396...

DISCUSSION...ISOLATED THUNDERSTORM HAS DEVELOPED OVER MO NEAR
JEFFERSON CITY. ACTIVITY IS ALONG E-W STATIONARY FRONT. CAP APPEARS
TO BE WEAKENING...THUS EXPECT ADDITIONAL THUNDERSTORM DEVELOPMENT
ALONG THE BOUNDARY THROUGH THIS EVENING. VAD WIND PROFILE FROM ST.
CHARLES MO SHOWS SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS. 


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. 
MEAN STORM MOTION VECTOR 27030.


...VESCIO

392,0920 392,0874 371,0874 372,0920

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 2:00 AM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 33 more5 hr
May 21, 11:00 PM CDTSevere Thunderstorm WatchSPCAdair, Clark, Grundy, Knox, Lewis, Linn and 11 more6 hr
May 21, 11:30 PM CDTTornado WatchSPCAndrew, Atchison, Daviess, DeKalb, Gentry, Harrison and 3 more6 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.