000
AXPZ20 KNHC 040321
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC FRI DEC 04 2015

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 FEATURE...

GULF OF TEHUANTEPEC STORM WARNING...GALE FORCE NORTHERLY WINDS
CURRENTLY OBSERVED ARE EXPECTED TO GRADUALLY INCREASE TO MINIMAL
STORM FORCE WITHIN A NARROW SWATH SURROUNDED BY A LARGE AREA OF
STRONG GALE FORCE LATER TONIGHT AND CONTINUE THROUGH SUNRISE ON
FRI. THE GRADIENT WILL RELAX BY FRI AFTERNOON SUPPORTING STRONG
GALE CONDITIONS INTO EARLY FRI NIGHT...THEN INCREASING AGAIN TO
MINIMAL STORM FORCE LATE FRI NIGHT AND CONTINUING THROUGH
SUNRISE ON SAT. THE GRADIENT WILL THEN RELAX WITH STRONG GALE
CONDITIONS CONTINUING THROUGH AT LEAST LATE TUE NIGHT. WAVE
GUIDANCE BUILDS SEAS TO AS HIGH AS 23 FT NEAR 14.5N95W DURING
THE STORM EVENTS. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

A 1008 MB SURFACE LOW IS ANALYZED NEAR 11N75W ALONG THE
CARIBBEAN COAST OF NW COLOMBIA WITH LOW PRESSURE EXTENDING SW
OVER THE FAR EASTERN TROPICAL EPAC...GENERALLY TO THE N OF 02N E
OF 90W. ISOLATED MODERATE TO STRONG CONVECTION IS CURRENTLY
FLARING WITHIN WITHIN 120 NM OF 05N85W AND ALSO ALONG THE
PACIFIC COAST OF PANAMA WITHIN 30 NM OF 07N81W. LOCALLY OVERCAST
LOW-MID LAYERED CLOUDS...WITH EMBEDDED ISOLATED TSTMS... IS
NOTED ELSEWHERE WITHIN 180 NM OF A LINE FROM 05N80W TO 02N96W.

SCATTEROMETER WINDS INDICATE THAT AN ITCZ FORMS NEAR 05N90W AND
CONTINUES WNW TO 05N114W...THEN TURNS WSW TO 03N121W...THEN WNW
TO BEYOND 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION
IS OBSERVED WITHIN 180 NM OF 05N103W...WITHIN 60 NM OF
02N118W...AND WITHIN 60 NM EITHER SODE OF A LINE FROM 07N128W TO
08N140W.  
 
...DISCUSSION...

A WEAKENING COLD FRONT...CURRENTLY ALONG POSITION FROM 32N122W
TO 25N140W...WILL CONTINUE E ACROSS THE SUBTROPICAL WATERS WITH
ASSOCIATED WINDS AT 20 KT OR LESS ACROSS THE DISCUSSION WATERS
TO THE S OF 32N. REMNANTS OF THIS FAST MOVING FRONT WILL PASS
ACROSS THE NORTHERN BAJA CALIFORNIA PENINSULA EARLY FRI WITH
ONLY THE SLIGHEST W TO NW WIND SHIFT. A SECONDARY FRONT IS NOTED
ABOUT 150 NM BEHIND THE INITIAL FRONT...BUT WILL NOT BE ADDED TO
THE SURFACE ANALYSIS OR MARINE GRAPHICS FOR SIMPLICITY. THE MAIN
CONCERN IS THE ASSOCIATED LONG PERIOD NW SWELL WHICH HAS BUILT
COMBINED SEAS TO 17 FT ALONG 32N BETWEEN 133-140W WITH SEAS 12
FT OR GREATER CURRENTLY W OF A LINE FROM 32N125W TO 22N140W.
EXPECT THE EASTERN EXTEND OF SEAS 12 FT OR GREATER TO SHIFT E
AND SE AND MERGE WITH TRADE WIND SEAS ACROSS THE TROPICS ON
FRI...ALL TO THE W OF A LINE FROM 32N118W TO 06N134W. LATEST
WAVE GUIDANCE SUGGESTS SEAS WILL SUBSIDE SOME WITH A MAX OF
ABOUT 10 FT REACHING THE PACIFIC COAST OF THE BAJA PENINSULA TO
THE N OF 28N LATE FRI NIGHT...WITH SEAS SUBSIDING THROUGH THE
DAY ON SAT. EXPECT COMBINED SEAS OF AT LEAST 6-8 FT TO CONTINUE
ALONG THE BAJA PENINSULA THROUGH MIDDAY SUN THEN BEGIN TO
SUBSIDE FROM THE N. ANOTHER COLD FRONT WILL ENTER THE FAR NW
WATERS NEAR 30N140W ON SAT NIGHT ACCOMPANIED BY ANOTHER BATCH OF
12 FT OR GREATER SEAS WHICH WILL ARRIVE AT THE NORTHERN BAJA
PENINSULA LATE MON.
 
FURTHER S...THE PRESSURE GRADIENT IS SUPPORTING AN AREA OF
STRONG NE TRADE WINDS...ROUGHLY ACROSS THE TROPICS FROM 08-16N W
OF 132W WITH COMBINED SEAS OF 9-12 FT. LONG PERIOD CROSS
EQUATORIAL SWELL...AND LONG PERIOD NW SWELL...ARE MIXING WITH
FRESH TRADES ELSEWHERE W OF A LINE FROM THE NORTHERN BAJA
CALIFORNIA PENINSULA TO EQUATOR AT 97W RESULTING IN COMBINED
SEAS OF 8-11 FT. THE AREA OF ENHANCED TRADES WILL EXPAND TO
COVER THE WATERS FROM 06-19N W OF 130W ON FRI...THEN THE
GRADIENT WILL RELAX ON FRI NIGHT THROUGH EARLY SAT...THEN THE
GRADIENT WILL TIGHTEN AGAIN WITH STRONG TRADES DEVELOPING ACROSS
THE TROPICS N OF THE ITCZ AND W OF 122W ON SUN. 
 
GULF OF PAPAGAYO...EXPECT STRONG NE 20-25 KT WINDS TO DEVELOP
LATE TONIGHT INTO FRI MORNING...THEN RELAX SOME ON FRI
AFTERNOON... THEN RESUME AGAIN FRI NIGHT AND CONTINUE THROUGH
THE WEEKEND. THE NE SWELL FROM THESE SURGES WILL SPREAD SW AND
MERGE WITH CROSS EQUATORIAL SOUTHERLY SWELL...AS WELL AS NW
SWELL PARTIALLY ORIGINATING IN THE GULF OF
TEHUANTEPEC...RESULTING IN LARGE SEAS TO AS FAR S AS 08N93W.
 
GULF OF CALIFORNIA...THE GRADIENT WILL INCREASE BEHIND THE WEAK
COLD FRONT ON FRI NIGHT WITH STRONG NW WINDS AT 20-25 KT
DEVELOPING ACROSS THE FAR NORTHERN GULF ON SAT MORNING. THESE
CONDITIONS WILL SPREAD S ACROSS THE ENTIRE GULF OF CALIFORNIA ON
SAT NIGHT INTO SUN BEFORE DIMINISHING FROM THE N BEGINNING LATE
SUN. EXPECT SEAS TO BUILD AS HIGH AS 7 FT IN LONG OPEN FETCH
WATERS.

$$
NELSON