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 1
NWS STORM PREDICTION CENTER NORMAN OK
435 AM CST THU JAN 10 2013
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL LOUISIANA
SOUTHWEST MISSISSIPPI
COASTAL WATERS
EFFECTIVE THIS THURSDAY MORNING FROM 435 AM UNTIL NOON 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 45 STATUTE
MILES EAST AND WEST OF A LINE FROM 10 MILES NORTH OF NATCHEZ
MISSISSIPPI TO 40 MILES SOUTH SOUTHEAST OF INTRACOASTAL CITY
LOUISIANA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).
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.
DISCUSSION...EXISTING SSW-NNE SQLN HAS SHOWN SOME SIGNS OF
PERSISTENT STRENGTHENING IN THE PAST HOUR. THIS MAY BE DUE TO /1/
ARRIVAL OF DEEPER/STRONGER LOW-LVL WLY FLOW TO ITS LEADING EDGE /PER
LCH VWP/...AND /2/ TO PERHAPS INCREASED LARGE SCALE ASCENT NEARING
REGION /PER WATER VAPOR IMAGERY./ AT ANY RATE...AREA VWP DATA SHOW
AMPLE LOW-LVL SHEAR TO SUPPORT LOW-LVL MESO/POSSIBLE TORNADOES GIVEN
PERSISTENT ESELY SFC WINDS E OF SQLN LINE. ALSO...REGION IS
SUFFICIENTLY MOIST /DEWPOINTS IN THE UPR 60S TO AROUND 70F/ TO
SUPPORT SUSTAINED UPDRAFTS...DESPITE RELATIVELY WEAK MID-LVL LAPSE
RATES....GIVEN PRESENCE OF A SOURCE FOR LOW-LVL UPLIFT ALONG SQLN
GUST FRONT.
OVERALL SETUP SUGGESTS A POSSIBLY INCREASING RISK FOR EMBEDDED
LEWPS/ROTATING STRUCTURES CAPABLE OF TORNADOES/LOCALLY DMGG WIND AS
THE SQLN DEVELOPS FARTHER NNEWD...AND MOVES GENERALLY
ENEWD...THROUGH LATER THIS MORNING.
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
400. MEAN STORM MOTION VECTOR 21030.
...CORFIDI
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW1
WW 1 TORNADO LA MS CW 101035Z - 101800Z
AXIS..45 STATUTE MILES EAST AND WEST OF LINE..
10N HEZ/NATCHEZ MS/ - 40SSE 7R4/INTRACOASTAL CITY LA/
..AVIATION COORDS.. 40NM E/W /59SE MLU - 80SSW BTR/
HAIL SURFACE AND ALOFT..0.5 INCH. WIND GUSTS..60 KNOTS.
MAX TOPS TO 400. MEAN STORM MOTION VECTOR 21030.
LAT...LON 31769052 29239112 29239262 31769206
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU1.
Watch 1 Status Report Messages:
STATUS REPORT #1 ON WW 1
VALID 101250Z - 101340Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 S 7R4 TO
25 ESE LFT TO 40 NW BTR TO 25 NNE ESF.
..GUYER..01/10/13
ATTN...WFO...LCH...LIX...JAN...SHV...
&&
STATUS REPORT FOR WT 1
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
LAC025-045-099-101-113-101340-
LA
. LOUISIANA PARISHES INCLUDED ARE
CATAHOULA IBERIA ST. MARTIN
ST. MARY VERMILION
$$
GMZ435-455-101340-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
VERMILION BAY
COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY
LA OUT 20 NM
$$
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 (40%)
|
Probability of 1 or more strong (F2-F5) tornadoes
|
Low (20%)
|
Wind
Probability of 10 or more severe wind events
|
Mod (30%)
|
Probability of 1 or more wind events > 65 knots
|
Low (10%)
|
Hail
Probability of 10 or more severe hail events
|
Low (<5%)
|
Probability
of 1 or
more hailstones > 2 inches
|
Low (<5%)
|
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
|
High (70%)
|
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% (F2-F5 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 
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