000 AXPZ20 KNHC 312208 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU DEC 31 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...SPECIAL FEATURES... STRONG TO NEAR GALE FORCE N TO NE WINDS ARE OCCURRING IN THE GULF OF TEHUANTEPEC REGION AND ARE EXPECTED TO INCREASE TO GALE FORCE BY LATE FRIDAY INTO EARLY SATURDAY AS A COLD FRONT AND THE ASSOCIATED COLD AIR MASS PUSHES ACROSS THE GULF OF MEXICO PRODUCING INCREASED AND PERSISTENT NORTHERLY FLOW THROUGH THE CHIVELA PASS INTO THE GULF REGION. THESE GALE FORCE WINDS ARE FORECAST TO CONTINUE THROUGH EARLY MON. SEAS ARE EXPECTED TO RANGE FROM 8 TO 10 FT UNTIL THE GALE FORCE WINDS EVENTUALLY BUILD SEAS INTO THE 10 TO 15 FT RANGE LATE FRIDAY THROUGH SATURDAY. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFEP2/FZPN03 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... ITCZ AXIS EXTENDS FROM 04N87W TO 06N115W TO 04N130W TO 04N140W. NO SIGNIFICANT CONVECTION. ...DISCUSSION... HIGH PRESSURE CONTINUES TO INFLUENCE MOST OF THE REGION WITH A 1025 MB HIGH CENTERED N OF THE DISCUSSION AREA NEAR 38N127W. A RIDGE AXIS EXTENDS FROM THE HIGH SE TO NEAR 20N110W. THE PRESSURE GRADIENT BETWEEN THE HIGH AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS GENERATING AN AREA OF FRESH TO STRONG TRADE WINDS FROM 10N TO 15N BETWEEN 115W AND 127W WITH SEAS 8 TO 10 FT. FAIRLY VIGOROUS SHORTWAVE TROUGH EXTENDS FROM A CYCLONIC CIRCULATION NEAR 30N116W STRETCHING SW TO 20N125W AND IS APPROACHING BAJA CALIFORNIA. MEANWHILE...THE NEXT SHARP MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM 32N136W TO 25N138W AND IS CURRENTLY IMPACTING THE FAR NW CORNER OF THE REGION N OF 24N W OF 137W. THIS TROUGHING SUPPORTS A RAPIDLY WEAKENING COLD FRONT EXTENDING FROM 30N137W TO 24N140W. EARLIER SCATTEROMETER DATA INDICATED AN AREA OF SOUTHERLY WINDS AHEAD OF THE FRONT GENERALLY N OF 28N E OF THE FRONT TO 135W. THESE WINDS HAVE SINCE WEAKENED. SEAS TO 9 FT IN NW SWELL CURRENTLY FOLLOWS IN WAKE OF THE FRONT...HOWEVER BY SATURDAY THE SWELL WILL HAVE OVERTAKEN THE WEAKENING FRONT AND EXTEND NW OF A LINE FROM 30N128W TO 08N140W. A NEW COLD FRONT IS FORECAST TO MOVE INTO THE NW PORTION OF THE AREA LATE FRI NIGHT INTO EARLY SATURDAY MORNING PRECEDED BY STRONG SW WINDS AND SEAS RAPIDLY BUILDING TO A RANGE OF 12 TO 16 FT. A SECONDARY AREA OF LOW PRESSURE IS FORECAST TO DIVE ESE INTO THE FAR NW CORNER OF THE AREA BY LATE SAT WITH W TO NW WINDS INCREASING TO NEAR GALE FORCE OVERNIGHT SAT. THE GFS MODEL IS THE MOST AGGRESSIVE IN DEPICTING GALE FORCE WINDS WITH SEAS BUILDING TO 20 FT. CROSS-EQUATORIAL SWELL WITH SEAS OF 8-9 FT ARE S OF 02N GENERALLY BETWEEN 105W AND 133W. THIS AREA OF SWELL WILL GRADUALLY SUBSIDE THROUGH EARLY FRI. GAP WINDS... GULFS OF PAPAGAYO AND PANAMA...STRONG TO GALE FORCE TRADES ACROSS THE SW CARIBBEAN SEA ARE RESULTING IN STRONG NE TO E GAP WINDS THROUGH THE GULF OF PAPAGAYO. THE AREA OF STRONG WINDS WILL REACH THEIR MAXIMUM EXTENT ON FRIDAY WITH SEAS BUILDING TO 11 FT. HOWEVER...THE STRONG NE SWELL WILL PROPAGATE EASTWARD AND LIKELY MERGE WITH NE SWELL GENERATED BY THE GULF OF TEHUANTEPEC EVENT WITH AN AREA OF 8FT SEAS GENERALLY FROM 06N TO 10N BETWEEN 94W TO 107W. THE CARIBBEAN SEA WINDS WILL ALSO INDUCE PULSES OF MODERATE TO FRESH NORTHERLY GAP WINDS ACROSS THE ISTHMUS OF PANAMA INTO THE GULF OF PANAMA DURING THE EVENING TO EARLY MORNING HOURS THROUGH SAT. $$ COBB