Tornado Watch 79

Issued

Mar 27, 2009, 2:54 PM CDT (19:54 UTC)

Expired

Mar 27, 2009, 9:00 PM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

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

30%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 298Mar 27, 2:34 PM CDT
• Mesoscale Discussion 303Mar 27, 6:18 PM CDT
• Mesoscale Discussion 305Mar 27, 8:21 PM CDT

218 
WWUS20 KWNS 271954
SEL9  
SPC WW 271954
LAZ000-MSZ000-280200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 79
NWS STORM PREDICTION CENTER NORMAN OK
255 PM CDT FRI MAR 27 2009

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

       SOUTHWEST INTO CENTRAL LOUISIANA
       EXTREME SOUTHWEST MISSISSIPPI

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 255 PM UNTIL 900
PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 55 MILES EAST NORTHEAST OF
FORT POLK LOUISIANA TO 30 MILES WEST OF LAFAYETTE LOUISIANA.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).

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 77...WW 78...

DISCUSSION...A CLUSTER OF STORMS HAS DEVELOPED RECENTLY IN THE
EXTREME SE TX IN THE ERN PART OF WW 77.  STRONG SURFACE HEATING HAS
OCCURRED ACROSS SRN LA IN ADVANCE OF THIS CONVECTION...AND S OF A
SLOW-MOVING OUTFLOW BOUNDARY LOCATED JUST N OF I-10.  THOUGH
BACKGROUND LOW-LEVEL WINDS ARE NOT STRONG...THE BACKED WINDS ALONG
THE BOUNDARY ARE RESULTING IN A RELATIVE MAXIMUM IN LOW-LEVEL SHEAR.
 THIS SOMEWHAT STRONGER SHEAR...COMBINED WITH STRONG SURFACE-BASED
INSTABILITY AND BOUNDARY LAYER DEWPOINTS NEAR 70 F...WILL LIKELY
SUPPORT A CLUSTER OF HP SUPERCELLS ALONG THE BOUNDARY FOR THE NEXT
FEW HOURS.  A COUPLE OF TORNADOES WILL BE POSSIBLE...IN ADDITION TO
LARGE HAIL AND DAMAGING WINDS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 27030.


...THOMPSON

Tornado Watches in Louisiana, 2009Tornado Watches in Mississippi, 2009Every tornado watch in 2009

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.