Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL0
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 520
NWS Storm Prediction Center Norman OK
740 AM CST Thu Dec 31 2020
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
The upper Texas coastal plain
Coastal Waters
* Effective this Thursday morning and afternoon from 740 AM until
300 PM CST.
* Primary threats include...
A few tornadoes possible
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Thunderstorms will increase in coverage and intensity
through the morning while spreading inland across the upper Texas
coast. The storm environment will gradually become more favorable
for supercells inland, with an attendant threat for a few tornadoes
and damaging winds through early to mid afternoon.
The tornado watch area is approximately along and 40 statute miles
north and south of a line from 25 miles west southwest of Angleton
TX to 20 miles north northeast of Port Arthur TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU0).
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.
&&
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 400. Mean
storm motion vector 21035.
...Thompson
SEL0
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 520
NWS Storm Prediction Center Norman OK
740 AM CST Thu Dec 31 2020
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
The upper Texas coastal plain
Coastal Waters
* Effective this Thursday morning and afternoon from 740 AM until
300 PM CST.
* Primary threats include...
A few tornadoes possible
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Thunderstorms will increase in coverage and intensity
through the morning while spreading inland across the upper Texas
coast. The storm environment will gradually become more favorable
for supercells inland, with an attendant threat for a few tornadoes
and damaging winds through early to mid afternoon.
The tornado watch area is approximately along and 40 statute miles
north and south of a line from 25 miles west southwest of Angleton
TX to 20 miles north northeast of Port Arthur TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU0).
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.
&&
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 400. Mean
storm motion vector 21035.
...Thompson
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW0
WW 520 TORNADO TX CW 311340Z - 312100Z
AXIS..40 STATUTE MILES NORTH AND SOUTH OF LINE..
25WSW LBX/ANGLETON TX/ - 20NNE BPT/PORT ARTHUR TX/
..AVIATION COORDS.. 35NM N/S /27ENE PSX - 41W LCH/
HAIL SURFACE AND ALOFT..1 INCH. WIND GUSTS..60 KNOTS.
MAX TOPS TO 400. MEAN STORM MOTION VECTOR 21035.
LAT...LON 29569585 30809389 29649389 28409585
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU0.
Watch 520 Status Report Messages:
STATUS REPORT #5 ON WW 520
VALID 312045Z - 312140Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SSW BPT
TO 45 NW BPT.
..KERR..12/31/20
ATTN...WFO...HGX...LCH...
&&
STATUS REPORT FOR WT 520
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
TXC199-241-245-457-312140-
TX
. TEXAS COUNTIES INCLUDED ARE
HARDIN JASPER JEFFERSON
TYLER
$$
GMZ430-450-312140-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
SABINE LAKE
COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM
$$
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.
$$
STATUS REPORT #4 ON WW 520
VALID 311925Z - 312040Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 S GLS TO
30 NNE HOU.
..KERR..12/31/20
ATTN...WFO...HGX...LCH...
&&
STATUS REPORT FOR WT 520
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
TXC071-199-241-245-291-351-361-457-312040-
TX
. TEXAS COUNTIES INCLUDED ARE
CHAMBERS HARDIN JASPER
JEFFERSON LIBERTY NEWTON
ORANGE TYLER
$$
GMZ335-355-430-450-312040-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
GALVESTON BAY
COASTAL WATERS FROM HIGH ISLAND TO FREEPORT TX OUT 20 NM
SABINE LAKE
COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX 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 #3 ON WW 520
VALID 311825Z - 311940Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 ESE LBX
TO 15 NNW HOU.
..KERR..12/31/20
ATTN...WFO...HGX...LCH...
&&
STATUS REPORT FOR WT 520
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
TXC071-167-199-201-241-245-291-351-361-457-311940-
TX
. TEXAS COUNTIES INCLUDED ARE
CHAMBERS GALVESTON HARDIN
HARRIS JASPER JEFFERSON
LIBERTY NEWTON ORANGE
TYLER
$$
GMZ335-355-430-450-311940-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
GALVESTON BAY
COASTAL WATERS FROM HIGH ISLAND TO FREEPORT TX OUT 20 NM
SABINE LAKE
COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM
$$
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.
$$
STATUS REPORT #2 ON WW 520
VALID 311735Z - 311840Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SE LBX TO
20 WNW HOU.
..KERR..12/31/20
ATTN...WFO...HGX...LCH...
&&
STATUS REPORT FOR WT 520
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
TXC039-071-167-199-201-241-245-291-351-361-457-311840-
TX
. TEXAS COUNTIES INCLUDED ARE
BRAZORIA CHAMBERS GALVESTON
HARDIN HARRIS JASPER
JEFFERSON LIBERTY NEWTON
ORANGE TYLER
$$
GMZ335-355-430-450-311840-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
GALVESTON BAY
COASTAL WATERS FROM HIGH ISLAND TO FREEPORT TX OUT 20 NM
SABINE LAKE
COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX 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 520
VALID 311630Z - 311740Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 ESE PSX
TO 25 WNW LBX.
..KERR..12/31/20
ATTN...WFO...HGX...LCH...
&&
STATUS REPORT FOR WT 520
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
TXC039-071-157-167-199-201-241-245-291-351-361-457-311740-
TX
. TEXAS COUNTIES INCLUDED ARE
BRAZORIA CHAMBERS FORT BEND
GALVESTON HARDIN HARRIS
JASPER JEFFERSON LIBERTY
NEWTON ORANGE TYLER
$$
GMZ335-350-355-430-450-311740-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
GALVESTON BAY
COASTAL WATERS FROM FREEPORT TO MATAGORDA SHIP CHANNEL TX OUT 20
NM
COASTAL WATERS FROM HIGH ISLAND TO FREEPORT TX OUT 20 NM
SABINE LAKE
COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM
$$
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
|
Low (20%)
|
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 (20%)
|
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.
weather.gov 
@NWSSPC
