000
AXPZ20 KNHC 150327
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC MON DEC 15 2014

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 
0300 UTC.  
      
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
           
THE MONSOON TROUGH EXTENDS FROM 09N84W TO 1010 MB LOW PRES NEAR 
08N85W TO 05N95W. THE ITCZ AXIS CONTINUES FROM 05N95W TO 08N114W 
THEN RESUMES W OF A TROUGH FROM 08N116W TO 06N130W TO 06N140W. 
OUTSIDE OF THE CONVECTION ASSOCIATED WITH THE TROUGH...SCATTERED 
MODERATE CONVECTION IS NOTED FROM 05N TO 07N BETWEEN 135W AND 
137W. 

...DISCUSSION...

A COLD FRONT ENTERS THE FORECAST AREA NEAR 30N130W THEN EXTENDS 
SW TO NEAR 24N140W. SCATTEROMETER DATA SHOWED FRESH TO STRONG SW 
WINDS N OF 29N JUST AHEAD OF THE FRONT...AND MAINLY MODERATE NW 
WINDS W OF THE FRONT. AN ALTIMETER SATELLITE DATA ALSO INDICATED 
10 TO 15 FT SEAS BEHIND THE FRONT. ANOTHER SET OF LONG PERIOD NW 
SWELLS WITH SIGNIFICANT WAVE HEIGHTS AS HIGH OF 18-19 FT IS 
MOVING INTO THE NW WATERS IN THE WAKE OF THE FRONT. SEAS OF 8 FT 
OR GREATER EXTEND ALL THE WAY SE TO A LINE FROM 23N110W TO 
11N100W TO 05N100W TO 03.4S103W. THESE SEAS ARE MAINLY DUE TO AN 
OLDER SET OF NW SWELL WHICH ARRIVED BEHIND THE PREVIOUS COLD 
FRONT.

THE FRONT WILL MOVE EASTWARD ACROSS THE N WATERS REACHING A 
POSITION FROM 30N123W TO 22N125W TO 21N140W BY 24 HOURS...AND 
FROM 30N116W TO 22N121W BY 48 HOURS. THE WESTERN PART OF THE 
FRONT WILL BEGIN TO GRADUALLY DISSIPATE ON MON. THE ASSOCIATED 
NW SWELL WILL CONTINUE TO PROPAGATE TO THE SE WHILE THE OLD AREA 
OF NW SWELL CURRENTLY WELL OUT AHEAD OF THIS NEW FRONT DECAYS. 
 
EAST OF THE COLD FRONT...1020 MB HIGH PRESSURE IS LOCATED NEAR 
30N121W WITH A WEAK RIDGE EXTENDING TO THE SE TO NEAR 20N110W... 
AND ALSO SW TO NEAR 26N130W. THE HIGH IS FORECAST TO MOVE SE 
AHEAD OF THE FRONT REACHING 25N119W BY 24 HOURS. GENERALLY 
GENTLE TO MODERATE WINDS PERSIST IN THE AREA OF THE HIGH PRES N 
OF 20N E OF 130W. MODERATE TRADE WINDS ARE NOTED ON THE SOUTHERN 
PERIPHERY OF THE RIDGE S OF 20N. 
 
A WEAK TROUGH IS EMBEDDED WITHIN THE ITCZ AND EXTENDS FROM 
11N114W TO 06N115W. SCATTERED MODERATE CONVECTION IS SEEN ON 
SATELLITE IMAGERY MAINLY E OF THE TROUGH AXIS FROM 07N TO 10N 
BETWEEN 110W AND 117W. A WEAK 1010 MB LOW PRESSURE IS ALONG THE  
MONSOON TROUGH NEAR 08N85W. THIS LOW WILL REMAIN NEARLY 
STATIONARY THROUGH THE NEXT 24-48 HOURS WITH LITTLE CHANGE.

GULF OF CALIFORNIA...AN EARLIER ASCAT PASS SHOWED GENTLE TO 
MODERATE NW-N WINDS ACROSS THIS GULF. SEAS OF 2 FT OR LESS 
PREVAIL. WINDS WILL BECOME VARIABLE N OF 28N MON NIGHT INTO 
EARLY TUE WITH SEAS LESS THAN 2 FT.

LOOKING AHEAD...EXPECT INCREASING WINDS ACROSS THE GULFS OF 
TEHUANTEPEC AND PAPAGAYO TUE NIGHT INTO WED MORNING AS HIGH PRES 
BUILDS ACROSS THE GULF OF MEXICO AND THE NW CARIBBEAN AND THE 
REGIONAL PRESSURE GRADIENT TIGHTENS. MARINE GUIDANCE SUGGESTS 
NORTHERLY WINDS OF 20-25 KT ACROSS THE GULF OF TEHUANTEPEC WITH 
BUILDING SEAS OF 8-9 FT. NE WINDS OF 20-25 KT ARE ALSO EXPECTED 
IN THE GULF OF PAPAGAYO WITH SEAS OF 6-7 FT.  

$$
GR