Tornado Watch 556

Issued

Jun 12, 1998, 4:30 PM CDT (21:30 UTC)

Expired

Jun 12, 1998, 9:00 PM CDT

In force

5 hr

Issued by

the Storm Prediction Center

The St Louis radar (KLSX), 23 km from the middle of the area, began a volume at 21:32 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.

490 
WWUS9 KMKC 122108
SEL6  
MKC WW 122108
MOZ000-ILZ000-130200-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 556
STORM PREDICTION CENTER NORMAN OK
408 PM CDT FRI JUN 12 1998

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

   CENTRAL AND  EASTERN MISSOURI                           
   SOUTHERN ILLINOIS                           

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 430 PM UNTIL 900
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 30 MILES NORTHWEST OF FORT LEONARD WOOD
MISSOURI TO 50 MILES EAST OF SALEM 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 553...WW 555...

DISCUSSION...THUNDERSTORMS ARE INCREASING ALONG PRE-FRONTAL
CONVERGENCE ZONE OVER E-CENTRAL MO. ACTIVITY IS EXPECTED TO RAPIDLY
BECOME SEVERE AS IT MOVES THROUGH AXIS OF HIGH INSTABILITY.
ALTHOUGH WIND FIELDS ARE LARGELY UNIDIRECTIONAL...MAGNITUDE OF
INSTABILITY AND BRN SHEAR VALUES NEAR 90 M2/S2 SUGGEST A THREAT FOR
ISOLATED TORNADOES. 

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

390,0923 393,0880 373,0880 370,0923

Tornado Watches in Illinois, 1998Tornado Watches in Missouri, 1998Every tornado watch in 1998

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.