000
AXPZ20 KNHC 280332
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU NOV 28 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 
0330 UTC.

...SPECIAL FEATURE...

GULF OF TEHUANTEPEC...THE MOST RECENT SCATTEROMETER PASS 
CONFIRMED THE STORM WARNING FOR WINDS OF 45-55 KT WITHIN 30 NM 
EITHER SIDE OF A LINE FROM 16N95W TO 14N95.5W...SURROUNDED BY 
GALE FORCE WINDS OF 30-45 KT WITHIN 60 NM EITHER SIDE OF A LINE 
FROM 16N95W TO 14N95.5W TO 12N97W. MAXIMUM SEAS OF 24 FT ARE 
FORECAST IN THE AREA OF STORM CONDITIONS. THE LATEST GUIDANCE IS 
IN AGREEMENT THAT STORM FORCE WINDS WILL PERSIST THROUGH LATE 
THU MORNING... THEN STRONG GALE WINDS WILL THEN CONTINUE THROUGH 
SUNRISE ON SAT WITH PULSES TO MINIMAL GALE CONTINUING THROUGH 
SUNRISE ON SUN. THE RESULTANT N-NE SWELL WILL MIX WITH LONG 
PERIOD CROSS-EQUATORIAL SOUTHERLY SWELL...RESULTING IN SEAS 
LARGER THAN 8 FT ACROSS THE WATERS FROM 05-14N BETWEEN 93-107W 
BY LATE THU. THE AREA OF NE-E SWELL WILL PROPAGATE W WITH SEAS 8 
FT OR GREATER FROM 04N-14N BETWEEN 93W-115W BY LATE FRI.  

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

THE MONSOON TROUGH EXTENDS W FROM THE COLOMBIAN COAST AT 09N78W 
ACROSS THE GULF OF PANAMA...THEN ACROSS NW PANAMA AND SOUTHERN 
COSTA RICA TO THE COAST OF COSTA RICA AT 09N84W...THEN DIPS SW 
TO 07N98W...THEN NW TO 09N115W TO 09N126W WHERE SCATTEROMETER 
WINDS INDICATE A TRANSITION TO AN ITCZ WHICH EXTENDS W TO THE 
SOUTHERN END OF AN EMBEDDED TROUGH AT 10N130W. THE ITCZ RESUMES 
W OF THE TROUGH NEAR 10N131W AND CONTINUES SW TO BEYOND 
08N140W. 

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ALONG 
THE MONSOON TROUGH WITHIN 120 NM EITHER SIDE OF A LINE FROM 
07N89W TO 08N101W TO 09N120W AND ALONG THE ITCZ WITHIN 60 NM 
EITHER SIDE OF A LINE FROM 10N131W TO 08N140W.

CLUSTERS OF SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED WELL N OF THE MONSOON TROUGH...WITHIN 30 NM OF 
11.5N87.5W...WITHIN 45 NM OF 13.5N92W...WITHIN 60 NM OF 12.5103W 
AND 30 NM OF 16.5N117W.

...DISCUSSION...

A COLD FRONT EXTENDING FROM 32N124W TO 24N140W IS PRECEDED BY
SOUTHERLY WINDS AT 20-25 KT/SEAS 7-12 FT TO THE N OF 27N WITHIN
150 NM E OF THE FRONT. THE POST-FRONTAL WESTERLY FLOW IS ALSO
AT 20-25 KT ACROSS THE PACIFIC WATERS N OF 28N WITHIN ABOUT 480
NM W OF THE FRONT. LARGE NW SWELLS IN THE WAKE OF THE FRONT ARE 
MIXING WITH LONG PERIOD CROSS EQUATORIAL SE SWELL...RESULTING IN 
COMBINED SEAS OF 11-18 FT N OF 28N W OF THE FRONT...WITH SEAS OF 
8-13 FT ACROSS THE WATERS S OF 28N W OF THE FRONT. THE FRONT 
WILL LOSE ITS MOMENTUM ON THU WITH WINDS DIMINISHING TO 15-20 KT 
N OF 27N W OF THE FRONT. HOWEVER...LARGE COMBINED SEAS OF 10-15 
FT WILL CONTINUE W OF THE FRONT ON THU. THESE NW SWELLS WITH 
COMBINED SEAS OF 6-9 FT...WILL REACH THE PACIFIC COAST OF THE 
NORTHERN BAJA CALIFORNIA PENINSULA BRIEFLY ON FRI MORNING...WITH 
SEAS 4-7 FT ALONG THE ENTIRE BAJA PENINSULA BY LATE FRI 
NIGHT...THEN BEGINNING TO SUBSIDE ON SAT.

A SURFACE LOW WILL SWING SE INTO THE N-CENTRAL WATERS NEAR 
29N127W ON FRI WITH THE NORTHERLY FLOW W OF THE LOW INCREASING
TO 20-25 KT AND SPREADING S ACROSS THE DISCUSSION WATERS N
OF 27N W OF 130W ON FRI NIGHT....THEN SPREADING S TO AS FAR
S AS 24N ON SAT NIGHT.    

A SURFACE TROUGH EMBEDDED IN THE ITCZ EXTENDS FROM 07N131W TO
14N126W AND APPEARS TO BE LOSING IDENTITY. NE TRADES AT 15-20
KT/SEAS 6-8 FT ARE NOTED W OF THE TROUGH TO 140W. LONG PERIOD
NW SWELL WILL PROPAGATE SE ACROSS THE TROPICS W OF 120W 
MIXING WITH 15-20 KT NE TRADES AND CROSS-EQUATORIAL SE TRADES 
MAINTAINING SEAS OF 5-8 FT. 

GAP WINDS...N-NE 20-25 KT WINDS ARE EXPECTED TO SURGE THROUGH 
BOTH THE GULF OF FONSECA AND THE GULF OF PAPAGAYO TONIGHT. 
ALTHOUGH THE GULF OF FONSECA EVENT WILL BE BRIEF...AND ONLY 
PERSIST THROUGH SUNRISE ON THU...THE NE FLOW WILL CONTINUE TO 
SURGE AT 20-30 KT THROUGH THE GULF OF PAPAGAYO THROUGH SUNRISE 
ON SUN...WITH THE STRONGEST WINDS EXPECTED DURING MAXIMUM 
NOCTURNAL DRAINAGE LATE EACH NIGHT. THE RESULTANT NE SWELL WILL 
MIX WITH LONG PERIOD S SWELL WITH COMBINED SEAS OF 9 FT. THIS 
AREA OF MIXED SWELL WILL FURTHER MIX WITH THE N SWELL ALONG 93W 
FROM THE GULF OF TEHUANTEPEC EVENT. 
 
$$
NELSON