Tornado Watch 877

Issued

Nov 8, 2011, 5:30 PM CST (23:30 UTC)

Expired

Nov 9, 2011, 12:47 AM CST

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

0.5 in

Strongest gust expected

60 kt

The Shreveport radar (KSHV), 75 km from the middle of the area, began a volume at 23:30 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

30%

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

70%

• Mesoscale Discussion 2303Nov 8, 1:44 PM CST
• Mesoscale Discussion 2304Nov 8, 3:48 PM CST
• Mesoscale Discussion 2305Nov 8, 3:53 PM CST
• Mesoscale Discussion 2306Nov 8, 5:09 PM CST
• Mesoscale Discussion 2308Nov 8, 9:21 PM CST
• Mesoscale Discussion 2309Nov 8, 11:18 PM CST

251 
WWUS20 KWNS 082337
SEL7
SPC WW 082337
ARZ000-LAZ000-TXZ000-CWZ000-090700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 877
NWS STORM PREDICTION CENTER NORMAN OK
530 PM CST TUE NOV 8 2011

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

       SOUTHERN AND EASTERN ARKANSAS
       WESTERN AND CENTRAL LOUISIANA
       EAST TEXAS
       COASTAL WATERS

EFFECTIVE THIS TUESDAY AFTERNOON AND WEDNESDAY MORNING FROM 530
PM UNTIL 100 AM CST.

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 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES NORTHWEST OF PINE
BLUFF ARKANSAS TO 25 MILES EAST SOUTHEAST OF PORT ARTHUR TEXAS.
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...CONTINUE...WW 875...WW 876...

DISCUSSION...TSTMS...INCLUDING POSSIBLE SUPERCELLS...EXPECTED TO
PERSIST THROUGH AT LEAST MID EVE ALONG PRE-FRONTAL N-S CONFLUENCE
LINE IN E TX AND WRN/SRN LA.  OTHER STORMS MAY CONTINUE TO FORM
ALONG THE FRONT IN SW AR.  WITH TIME THE STORMS SHOULD MOVE/DEVELOP
GENERALLY NEWD. WHILE DIMINISHING LOW LVL CAPE ULTIMATELY WILL
WEAKEN UPDRAFT STRENGTH...CONTINUING PRESENCE OF RICH MOISTURE
INFLOW/SELY SFC WINDS LIKELY WILL MAINTAIN SOME RISK FOR
TORNADOES/LOCALLY DMGG WIND IN E TX/LA.
FARTHER N...COMPARATIVELY WEAKER LOW LVL LAPSE RATES/MORE LIMITED
MOISTURE MAY BE OFFSET BY STRONGER DEEP SHEAR/FORCING FOR ASCENT
ASSOCIATED WITH THE CONTINUED NE MOVEMENT OF OK UPR TROUGH TO
MAINTAIN A RISK FOR ISOLD TORNADOES/DMGG WIND IN SRN/ERN AR.  THIS
THREAT ULTIMATELY MAY EXTEND STILL FARTHER N/NE INTO CNTRL/NERN
AR...ALTHOUGH CONFIDENCE IN SVR THREAT IN THOSE AREAS ATTM SEEMS TOO
LOW TO WARRANT A WW.

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
450. MEAN STORM MOTION VECTOR 23035.


...CORFIDI

Tornado Watches in Louisiana, 2011Tornado Watches in Arkansas, 2011Tornado Watches in Texas, 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.