Tornado Watch 837

Issued

Sep 4, 2011, 9:42 PM CDT (02:42 UTC)

Expired

Sep 5, 2011, 7:00 AM CDT

In force

9 hr

Issued by

the Storm Prediction Center

Largest hail expected

0.5 in

Strongest gust expected

60 kt

The Mobile radar (KMOB), 66 km from the middle of the area, began a volume at 02:44 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

50%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

5%

One or more gusts of 65 knots or more

5%

Ten or more severe hail reports

5%

One or more hailstones of 2 inches or more

5%

Six or more combined severe hail and wind reports

30%

• Mesoscale Discussion 2126Sep 4, 6:29 PM CDT
• Mesoscale Discussion 2128Sep 4, 11:35 PM CDT
• Mesoscale Discussion 2129Sep 5, 4:26 AM CDT

726 
WWUS20 KWNS 050244
SEL7
SPC WW 050244
ALZ000-FLZ000-LAZ000-MSZ000-CWZ000-051200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 837
NWS STORM PREDICTION CENTER NORMAN OK
945 PM CDT SUN SEP 4 2011

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

       SOUTHWEST ALABAMA
       THE WESTERN FLORIDA PANHANDLE
       EXTREME SOUTHEAST LOUISIANA
       PARTS OF CENTRAL AND SOUTHEAST MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 945 PM UNTIL
700 AM CDT.

TORNADOES...HAIL TO 0.5 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 95 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 40 MILES NORTHWEST OF
SLIDELL LOUISIANA TO 15 MILES NORTHEAST OF CRESTVIEW FLORIDA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU7).

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 832. WATCH NUMBER 832 WILL NOT BE IN EFFECT AFTER
945 PM CDT. CONTINUE...WW 833...WW 836...

DISCUSSION...BROKEN BANDS OF CONVECTION CONTINUE TO FEED NWD ACROSS
SE LA/SRN MS/SW AL...TO THE E OF THE CIRCULATION CENTER OF TROPICAL
DEPRESSION LEE.  LITTLE MOTION OF THE CYCLONE IS EXPECTED IN THE
SHORT TERM...AND A SLOW EWD DRIFT MAY COMMENCE LATE TONIGHT IN
RESPONSE TO AN UPSTREAM TROUGH OVER OK.  THE MINIMAL CHANGES TO THE
SYSTEM STRUCTURE SUGGEST THAT THE THREAT FOR LOW-TOPPED
SUPERCELLS/TORNADOES WILL PERSIST IN THE SAME GENERAL AREAS FOR THE
MUCH OF THE OVERNIGHT PERIOD.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 18030.


...THOMPSON

Tornado Watches in Mississippi, 2011Tornado Watches in Alabama, 2011Tornado Watches in Louisiana, 2011Every tornado watch in 2011

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.