Tornado Watch 962

Issued

Dec 27, 2008, 10:58 AM CST (16:58 UTC)

Expired

Dec 27, 2008, 7:00 PM CST

In force

8 hr

Issued by

the Storm Prediction Center

Largest hail expected

1 in

Strongest gust expected

60 kt

The St Louis radar (KLSX), 33 km from the middle of the area, began a volume at 17:02 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.

Two or more tornadoes

40%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

40%

Ten or more severe hail reports

20%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 2530Dec 27, 8:03 AM CST
• Mesoscale Discussion 2531Dec 27, 8:48 AM CST
• Mesoscale Discussion 2532Dec 27, 9:34 AM CST
• Mesoscale Discussion 2535Dec 27, 10:26 AM CST
• Mesoscale Discussion 2536Dec 27, 11:46 AM CST
• Mesoscale Discussion 2538Dec 27, 1:54 PM CST
• Mesoscale Discussion 2540Dec 27, 3:46 PM CST
• Mesoscale Discussion 2541Dec 27, 5:06 PM CST

997 
WWUS20 KWNS 271659
SEL2  
SPC WW 271659
ILZ000-MOZ000-280100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 962
NWS STORM PREDICTION CENTER NORMAN OK
1100 AM CST SAT DEC 27 2008

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

       CENTRAL ILLINOIS
       SOUTHERN INTO EASTERN MISSOURI

EFFECTIVE THIS SATURDAY MORNING AND EVENING FROM 1100 AM UNTIL
700 PM CST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES SOUTHWEST OF WEST
PLAINS MISSOURI TO 10 MILES NORTH NORTHEAST OF MARSEILLES
ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

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 959. WATCH NUMBER 959 WILL NOT BE IN EFFECT AFTER
1100 AM CST. CONTINUE...WW 960...WW 961...

DISCUSSION...INTENSE...BROKEN SQUALL LINE WITH EMBEDDED
LEWP/SUPERCELLS AND THE POTENTIAL FOR ISOLATED/DISCRETE SUPERCELLS
AHEAD OF THE LINE WILL CONTINUE TO SPREAD ENEWD ACROSS WW THROUGH
THE LATE AFTERNOON/EARLY EVENING.  EXTREME LOW LEVEL SHEAR /50+ KT
JUST ABOVE THE SURFACE/ AND STRENGTHENING DEEP ASCENT/SURFACE
PRESSURE FALL MAXIMUM WILL ENHANCE THE RISK OF DAMAGING WINDS AND
POSSIBLE TORNADOES.  RISK MAY BE MITIGATED SOMEWHAT IN SRN PORTION
OF WW INTO THE EARLY AFTERNOON GIVEN PRECEDING SHALLOW MOIST
CONVECTION SPREADING ACROSS THE OZARKS.  HOWEVER...SUFFICIENT
RECOVERY WITH MODEST HEATING MAY STILL SUSTAIN A RISK AHEAD OF MAIN
SURFACE COLD FRONT THROUGH THE AFTERNOON ACROSS THIS REGION.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 23050.


...EVANS

Tornado Watches in Illinois, 2008Tornado Watches in Missouri, 2008Every tornado watch in 2008

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.