Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL1
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 521
NWS Storm Prediction Center Norman OK
120 PM CST Thu Dec 31 2020
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Southwest Louisiana
Far southeast Texas
Coastal Waters
* Effective this Thursday afternoon and evening from 120 PM until
900 PM CST.
* Primary threats include...
A few tornadoes and a couple intense tornadoes possible
Scattered damaging wind gusts to 70 mph possible
SUMMARY...Squall line across the northwest Gulf through southeast
Texas should advance north-northeast, with additional cells possible
ahead of it. Low-level shear is favorable for embedded supercells
capable of producing tornadoes in addition to damaging winds with
the line.
The tornado watch area is approximately along and 65 statute miles
east and west of a line from 40 miles south southwest of
Intracoastal City LA to 20 miles northeast of Fort Polk LA. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU1).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 520...
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 450. Mean
storm motion vector 19030.
...Grams
SEL1
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 521
NWS Storm Prediction Center Norman OK
120 PM CST Thu Dec 31 2020
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Southwest Louisiana
Far southeast Texas
Coastal Waters
* Effective this Thursday afternoon and evening from 120 PM until
900 PM CST.
* Primary threats include...
A few tornadoes and a couple intense tornadoes possible
Scattered damaging wind gusts to 70 mph possible
SUMMARY...Squall line across the northwest Gulf through southeast
Texas should advance north-northeast, with additional cells possible
ahead of it. Low-level shear is favorable for embedded supercells
capable of producing tornadoes in addition to damaging winds with
the line.
The tornado watch area is approximately along and 65 statute miles
east and west of a line from 40 miles south southwest of
Intracoastal City LA to 20 miles northeast of Fort Polk LA. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU1).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 520...
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 450. Mean
storm motion vector 19030.
...Grams
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW1
WW 521 TORNADO LA TX CW 311920Z - 010300Z
AXIS..65 STATUTE MILES EAST AND WEST OF LINE..
40SSW 7R4/INTRACOASTAL CITY LA/ - 20NE POE/FORT POLK LA/
..AVIATION COORDS.. 55NM E/W /66SE LCH - 23W AEX/
HAIL SURFACE AND ALOFT..1 INCH. WIND GUSTS..60 KNOTS.
MAX TOPS TO 450. MEAN STORM MOTION VECTOR 19030.
LAT...LON 29249346 31259404 31259184 29249131
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU1.
Watch 521 Status Report Messages:
STATUS REPORT #2 ON WW 521
VALID 312330Z - 010040Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 60 SE BPT TO
20 SW LCH TO 30 WNW LCH TO 40 NNE BPT.
..SPC..12/31/20
ATTN...WFO...LCH...
&&
STATUS REPORT FOR WT 521
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
LAC001-003-009-011-019-023-039-045-053-055-079-097-099-101-113-
115-010040-
LA
. LOUISIANA PARISHES INCLUDED ARE
ACADIA ALLEN AVOYELLES
BEAUREGARD CALCASIEU CAMERON
EVANGELINE IBERIA JEFFERSON DAVIS
LAFAYETTE RAPIDES ST. LANDRY
ST. MARTIN ST. MARY VERMILION
VERNON
$$
TXC351-010040-
TX
. TEXAS COUNTIES INCLUDED ARE
NEWTON
$$
GMZ432-435-452-455-010040-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
CALCASIEU LAKE
VERMILION BAY
COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM
COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY
LA OUT 20 NM
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #1 ON WW 521
VALID 312145Z - 312240Z
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..KERR..12/31/20
ATTN...WFO...LCH...
&&
STATUS REPORT FOR WT 521
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
LAC001-003-009-011-019-023-039-045-053-055-079-097-099-101-113-
115-312240-
LA
. LOUISIANA PARISHES INCLUDED ARE
ACADIA ALLEN AVOYELLES
BEAUREGARD CALCASIEU CAMERON
EVANGELINE IBERIA JEFFERSON DAVIS
LAFAYETTE RAPIDES ST. LANDRY
ST. MARTIN ST. MARY VERMILION
VERNON
$$
TXC351-361-312240-
TX
. TEXAS COUNTIES INCLUDED ARE
NEWTON ORANGE
$$
GMZ432-435-452-455-312240-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
CALCASIEU LAKE
VERMILION BAY
COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM
COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY
LA OUT 20 NM
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
Note:
Click for Complete Product Text.
Tornadoes
Probability of 2 or more tornadoes
|
Mod (50%)
|
Probability of 1 or more strong (EF2-EF5) tornadoes
|
Mod (30%)
|
Wind
Probability of 10 or more severe wind events
|
Mod (40%)
|
Probability of 1 or more wind events > 65 knots
|
Low (20%)
|
Hail
Probability of 10 or more severe hail events
|
Low (10%)
|
Probability of 1 or more hailstones > 2 inches
|
Low (10%)
|
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
|
Mod (60%)
|
For each watch, probabilities for particular events inside the watch
(listed above in each table) are determined by the issuing forecaster.
The "Low" category contains probability values ranging from less than 2%
to 20% (EF2-EF5 tornadoes), less than 5% to 20% (all other probabilities),
"Moderate" from 30% to 60%, and "High" from 70% to greater than 95%.
High values are bolded and lighter in color to provide awareness of
an increased threat for a particular event.
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