000
AXPZ20 KNHC 260345
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
0405 UTC TUE NOV 26 2013

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...SPECIAL FEATURES...
GALE CONDITIONS EXPECTED ACROSS GULF OF TEHUANTEPEC BY 0000 UTC 
WED INCREASING TO STORM CONDITIONS BY 1200 UTC WED. 

NORTHERLY WINDS CONTINUE TO QUICKLY DIMINISH ACROSS AND 
DOWNSTREAM OF THE GULF OF TEHUANTEPEC THIS EVENING AND HAVE 
DROPPED OFF TO 20 KT OR LESS...WITH SEAS SUBSIDING TO 8 FT. THIS 
IMPROVING TREND IS EXPECTED TO CONTINUE OVERNIGHT...BUT WILL BE 
SHORT LIVED AS A NEW BLAST OF COLD AIR ACROSS THE WESTERN GULF 
OF MEXICO PUSHES A COLD FRONT INTO THE BAY OF CAMPECHE LATE TUE 
AFTERNOON AND EVENING...AND GALE FORCE WINDS SPILL THROUGH THE 
CHIVELAS PASS AND BEGIN TO SPREAD ACROSS THE GULF OF TEHUANTEPEC 
TUE EVENING. 

SEA SURFACE TEMPERATURES ACROSS THE GULF OF TEHUANTEPEC HAVE 
REBOUNDED QUICKLY DURING THE PAST FEW DAYS...AND ARE NOW 27-28 
DEG C...AND SHOULD CREATE VERY UNSTABLE CONDITIONS ACROSS THE 
REGION AND ALLOW FOR VERY STRONG AND COLD WINDS ALOFT TO MIX 
DOWN TO THE SURFACE ON WED. STORM FORCE WINDS OF 50-55 KT ARE 
SUGGESTED BY GLOBAL MODELS ACROSS TEHUANTEPEC WED AFTERNOON AND 
EVENING BEFORE SUBSIDING TO STRONG GALES EARLY THU. GALES ARE 
THEN EXPECTED TO PERSIST INTO SUN. LOOK FOR SEAS TO BUILD IN 
EXCESS OF 20 FT WED AS WINDS QUICKLY INCREASE THROUGHOUT THE 
DAY. WITH SUCH A PROLONGED EVENT...A LARGE PLUME OF N TO NE 
SWELL GENERATED BY THE WINDS WILL PROPAGATE TO THE S AND 
SW...LIKELY REACHING ALL THE WAY TO 120W BY NEXT WEEKEND.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

MONSOON TROUGH EXTENDS FROM 10N75W TO 07.5N80W TO 10.5N85W TO 
06.5N95W TO 08N114W TO 11N118W...WHERE IT TERMINATES.  ITCZ 
BEGINS FROM 09N126W TO 08N140W. WIDELY SCATTERED MODERATE 
CONVECTION NOTED WITHIN 210 NM S OF TROUGH AXIS BETWEEN 79W AND 
86W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 
180 NM N AND 60 NM S OF ITCZ W OF 120W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 75 NM NW OF LINE FROM 17N111W 
TO 14N119W.

...DISCUSSION...
A SHARP MIDDLE TO UPPER LEVEL TROUGH HAS SHIFTED E ACROSS THE 
FAR WESTERN PORTION OF THE AREA WITH AXIS FROM 35N134W TO 
19N141W. AN ASSOCIATED COLD FRONT EXTENDS ACROSS THE AREA FROM 
30N134W TO 24N140W. SHOWERS AND ISOLATED TSTORMS OCCURRING E OF 
THE FRONT HAVE SHIFTED NE OUT OF THE AREA THIS EVENING.  W OF 
THE FRONT NW SWELLS ARE SUBSIDING...LEAVING SEAS NEAR 8 N OF 
29N. THE FRONT IS FORECAST TO DISSIPATE TONIGHT.

EAST OF THE FRONT A WEAK SURFACE RIDGE PERSISTS FROM A 1025 MB 
HIGH CENTERED OFFSHORE OF SOUTHERN CALIFORNIA SE TO 20N107W. THE 
PRES GRADIENT BETWEEN THE HIGH AND LOW PRESSURE ALONG THE E 
SLOPES OF THE SIERRA MADRE OCCIDENTALES IS PRODUCING FRESH NWLY 
WINDS 20-25 KT THROUGH ALL BUT EXTREME S PORTIONS OF THE GULF OF 
CALIFORNIA. THESE WINDS WILL SPREAD TO FULL LENGTH OF THE GULF 
OVERNIGHT...BUILDING SEAS TO NEAR 8 FT...WITH WINDS AND SEAS 
DIMINISHING TUE.

A MUCH STRONGER COLD FRONT IS FORECAST TO APPROACH THE NW 
PORTION TUE NIGHT AND EXTEND FROM 32N129N TO 26N140W. NW WINDS 
WILL INCREASE TO 20 TO 25 KT WITH SEAS BUILDING 10-15 FT W OF 
THE FRONT.

THE COLD FRONT EXPECTED TO MOVE ACROSS THE GULF OF MEXICO IN THE 
NEXT FEW DAYS IS FORECAST TO MOVE INTO THE NW CARIBBEAN ONE WED 
AND WILL ALLOW FRESH NE GAP WINDS TO SPILL ACROSS CENTRAL 
AMERICA AND THROUGH THE GULFS OF PAPAGAYO AND FONSECA...AND 
PULSE TO 25 KT EACH NIGHT...WED THROUGH SAT. 
 
$$
STRIPLING