Severe Thunderstorm Watch 682

Issued

Dec 16, 2012, 5:48 AM CST (11:48 UTC)

Expired

Dec 16, 2012, 1:00 PM CST

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

65 kt

The Houston radar (KHGX), 165 km from the middle of the area, began a volume at 11:48 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

10%

One or more EF2 to EF5 tornadoes

10%

Ten or more severe wind reports

50%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

10%

One or more hailstones of 2 inches or more

5%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 2160Dec 16, 5:00 AM CST
• Mesoscale Discussion 2161Dec 16, 9:54 AM CST

475 
WWUS20 KWNS 161151
SEL2
SPC WW 161151
LAZ000-TXZ000-CWZ000-161900-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 682
NWS STORM PREDICTION CENTER NORMAN OK
550 AM CST SUN DEC 16 2012

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

       WESTERN...CENTRAL AND NORTHERN LOUISIANA
       SOUTHEAST AND EAST TEXAS
       COASTAL WATERS

EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 550 AM UNTIL 100
PM CST.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 80 MILES SOUTHWEST
OF COLLEGE STATION TEXAS TO 40 MILES NORTH NORTHEAST OF NATCHEZ
MISSISSIPPI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...TSTMS FCST TO CONTINUE INCREASING IN COVERAGE AND
SPREAD FROM W-E ACROSS WW AREA...WHILE STRENGTHENING TO SVR LEVELS.
STG MID-UPPER WINDS -- E.G. 90 KT OBSERVED AROUND 6 KM AGL OVER LDB
PROFILER SITE -- WILL CONTRIBUTE TO FAVORABLE DEEP-LAYER SHEAR.
MEAN-WIND AND DEEP-SHEAR VECTORS WILL BE ALIGNED NEARLY PARALLEL TO
LOW-LEVEL FRONTAL/CONVERGENCE ZONE...SUPPORTING PREDOMINANT
QUASI-LINEAR AND CLUSTERED MODES...WITH LEWPS AND SMALL BOWS
POSSIBLE.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM
MOTION VECTOR 24035.


...EDWARDS

Severe Thunderstorm Watches in Texas, 2012Severe Thunderstorm Watches in Louisiana, 2012Every severe thunderstorm watch in 2012

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.