Tornado Watch 856

Issued

Oct 18, 2004, 12:40 PM CDT (17:40 UTC)

Expired

Oct 18, 2004, 6:00 PM CDT

In force

5 hr

Issued by

the Storm Prediction Center

The St Louis radar (KLSX), 107 km from the middle of the area, began a volume at 17:42 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.

• Mesoscale Discussion 2322Oct 18, 10:20 AM CDT
• Mesoscale Discussion 2324Oct 18, 12:04 PM CDT
• Mesoscale Discussion 2327Oct 18, 3:41 PM CDT

000 
WWUS20 KWNS 181742
SEL6  
SPC WW 181740
ILZ000-MOZ000-182300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 856
NWS STORM PREDICTION CENTER NORMAN OK
1240 PM CDT MON OCT 18 2004

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

       SOUTHERN ILLINOIS
       SOUTHCENTRAL AND SOUTHEAST MISSOURI

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 1240 PM UNTIL 600
PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 75 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 40 MILES WEST OF FORT LEONARD WOOD MISSOURI
TO 10 MILES SOUTH OF CARBONDALE 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 855...

DISCUSSION...AIR MASS RAPIDLY DESTABILIZING AHEAD OF SURFACE LOW
MOVING INTO SWRN MO AND S OF WARM FRONT EXTENDING EWD JUST S OF STL.
 WITH S/WV TROUGH CROSSING AREA...UPWARD MOTION AND SHEAR WILL BE
SUPPORTIVE FOR DEVELOPMENT OF SUPERCELL THUNDERSTORMS ALONG AND S OF
WARM FRONT.  ALONG WITH TORNADO THREAT...VERY LARGE HAIL IS ALSO
LIKELY WITH ANY SUPERCELL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 24035.


...HALES

385,0925 384,0891 363,0891 363,0925

Tornado Watches in Missouri, 2004Tornado Watches in Illinois, 2004Every tornado watch in 2004

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.