000
AXPZ20 KNHC 280926
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC...OVERNIGHT HIGH RESOLUTION SCATTEROMETER 
PASSES INDICATED A FEW 45-50 KT WIND BARBS WITH A SIGNIFICANT 
SURROUNDING AREA OF GALE FORCE WINDS. STORM FORCE WINDS ARE 
FORECAST TO CONTINUE THROUGH THE DAY...DIMINISHING TO HIGH-END 
GALE FORCE BY 00 UTC FRI. GALE CONDITIONS WILL THEN LIKELY 
PERSIST THROUGH LATE SAT/EARLY SUN BEFORE FINALLY DIMINISHING. 
MAXIMUM SIGNIFICANT WAVE HEIGHTS WILL BE 22-24 FT DURING THE 
STORM FORCE WINDS...SUBSIDING TO A MAXIMUM OF 17-19 FT BY 48 
HOURS. GIVEN THE PROLONGED DURATION AND LARGE EXTENT OF THE 
WINDS...AN IMPRESSIVE PLUME OF NE SWELL OF 8 FT OR GREATER WILL 
REACH ALL THE WAY TO 03N AND 120W BY 06 UTC SAT.

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

THE MONSOON TROUGH EXTENDS FROM 08N78W TO 09N84W TO 06N103W    
TO 09N133W. THE ITCZ EXTENDS FROM 09N133W TO 08N140W. SCATTERED 
MODERATE AND ISOLATED STRONG CONVECTION IS FROM 06N TO 09N 
BETWEEN 96W AND 102W...WITHIN 60 NM S OF THE MONSOON TROUGH 
BETWEEN 105W AND 108W...AND ALSO BETWEEN 128W AND 131W. SIMILAR 
CONVECTION IS WITHIN 60 NM S OF THE ITCZ BETWEEN 137W AND 139W.

...DISCUSSION...

A COLD FRONT EXTENDS FROM 1002 MB LOW PRES JUST N OF THE AREA 
NEAR 34N129W THROUGH 32N124W TO 26N130W TO 24N140W. FRESH TO 
STRONG NORTHERLY WINDS ARE WRAPPING AROUND THE BACK SIDE OF   
THE LOW SNEAKING INTO THE AREA N OF A LINE FROM 30N129W TO 
26N130W TO 28N132W TO 30N136W ALONG WITH LARGE 15-18 FT NW 
SWELL. SEAS OF 11-16 FT ARE ELSEWHERE W OF THE FRONT. MEANWHILE 
FRESH TO STRONG SW WINDS ARE N OF 26N WITHIN 120 NM E OF THE 
FRONT WITH NW SWELL OF 8-11 FT OUTRUNNING THE FRONT TO A LINE 
FROM 30N122W TO 16N140W. THE LOW IS FORECAST TO SINK S THROUGH 
24 HOURS REACHING 32N127W WHILE WEAKENING TO 1007 MB...THEN 
MOVING TO NEAR 27.5N128W BY 48 HOURS AS IT CONTINUES TO WEAKEN 
TO 1014 MB. THE PRES GRADIENT WILL TIGHTEN OVER THE NW WATERS 
BETWEEN THE LOW AND BUILDING HIGH PRES NW OF THE AREA AND AS A 
RESULT FRESH TO STRONG NE WINDS WILL BE W OF A LINE FROM 30N127W 
TO 27.5N128W TO 24N140W BY LATE FRI NIGHT/EARLY SAT. THE NW 
SWELL WILL BE DECAYING THROUGH THE NEXT 48 HOURS...DOWN TO 8-12 
FT BY THEN WHILE CONTINUING TO PROPAGATE TO THE SE COVERING THE 
WATERS N OF 11N W OF 115W.

A PAIR OF SURFACE TROUGHS ARE EMBEDDED IN THE MONSOON TROUGH  
AND ITCZ. THE EASTERN TROUGH EXTENDS FROM 17N119W TO 09N121W. 
SCATTEROMETER DATA INDICATES ONLY MODERATE WINDS NEAR THIS 
TROUGH WHILE SEAS ARE LESS THAN 8 FT. THE WESTERN TROUGH EXTENDS 
FROM 17N126W TO 08N131W. THE PRESSURE GRADIENT W OF THIS TROUGH 
IS TIGHT ENOUGH TO SUPPORT MODERATE TO FRESH TRADES AND A 
CORRESPONDING AREA OF 8-9 FT IN MIXED NE AND NW SWELL. THE 
TROUGHS WILL WEAKEN WHILE CONTINUING WESTWARD AROUND 10 KT WITH 
THE LARGE AREA OF NW SWELL MENTIONED ABOVE OVERTAKING SEAS 
ASSOCIATED WITH THESE FEATURES.

GAP WINDS...FRESH TO STRONG NE WINDS WILL SURGE THROUGH THE GULF 
OF PAPAGAYO THIS MORNING...PEAKING AT 30 KT AROUND SUNRISE TODAY 
WHILE SEAS BUILD TO UP TO 10 FT. SIMILAR CONDITIONS WILL PERSIST 
INTO THE WEEKEND WITH THE STRONGEST WINDS OCCURRING DURING 
MAXIMUM NOCTURNAL DRAINAGE LATE EACH NIGHT/EARLY MORNING.
 
$$
LEWITSKY