000
AXPZ20 KNHC 300317
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED DEC 30 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.   

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

SURFACE TROUGH EXTENDS FROM THE COAST OF COSTA RICA NEAR 10N85W
THEN TRANSITIONS TO THE ITCZ NEAR 06N92W. THE ITCZ EXTENDS
THROUGH 07N110W TO 08N125W TO BEYOND 04N140W. SCATTERED MODERATE
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 180 NM N OF THE AXIS
BETWEEN 126W AND 132W.

...DISCUSSION...                                              

IN GENERAL...BENIGN CONDITIONS CONTINUE ACROSS THE AREA AS HIGH
PRESSURE DOMINATES. A 1024 MB HIGH PRESSURE SYSTEM IS CENTERED N
OF THE DISCUSSION AREA NEAR 36N131W WITH A RIDGE STRETCHING SE
TO 32N130W TO NEAR 20N110W. THE WEAKENING SURFACE TROUGH
ASSOCIATED WITH A LARGE UPPER TROUGH OVER THE WESTERN U.S. HAS
DISSIPATED. THE PRESSURE GRADIENT BETWEEN LOWER PRESSURES OVER
MEXICO AND THE 1025 MB HIGH HAS RELAXED AND ALLOWED NW WINDS TO
DROP BELOW 20 KT OVER THE FAR NE PACIFIC AND THE GULF OF
CALIFORNIA. 

THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE CENTERED N OF
THE AREA AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ
CONTINUES TO SUPPORT AN AREA OF FRESH TO STRONG TRADE WINDS
WHICH APPEAR TO BE FOCUSED FROM 08N TO 20N BETWEEN 120W AND 133W
WITH SEAS IN THE 8 TO 10 FT RANGE...EXCEPT FOR HIGHER SEAS OF 10
TO 11 FT PRIMARILY IN NW SWELL FROM 14N-21N W OF 135W. THE HIGH
PRESSURE N OF THE AREA IS FORECAST TO GRADUALLY SHIFT EASTWARD
THROUGH THU WHILE A WEAK LOW-LEVEL TROUGH IS FORECAST TO BECOME
REFLECTED AT THE SURFACE FROM 15N122W TO 10N127W EARLY WED. MOST
OF THE FORCING WILL BE PROVIDED BY A SHARPENING MID/UPPER TROUGH
CURRENTLY ALONG 136W/137W. NE WINDS OF 20-25 KT ARE EXPECTED
WITHIN 180 NM W OF THE TROUGH ON WED WITH AN AREA OF 20-25 KT
WINDS REMAINING IN AN AREA FROM FROM 09N TO 14N BETWEEN 116W AND
124W AS THE TROUGH DISSIPATES. SEAS OF 8 TO 10 FT ARE FORECAST
IN AN AREA WITHIN 270 NM EITHER SIDE OF A LINE FROM 13N112W TO
11N125W TO 09N140W...WITH HIGHEST SEAS UP TO 10 FT FROM 10N-13N
BETWEEN 118W AND 124W.

SOUTHERLY SWELLS OF UP TO 8 FT ARE EXPECTED TO CROSS THE EQUATOR
BETWEEN 108W AND 120W OVERNIGHT AND N OF THE EQUATOR BY WED
MORNING. THESE 8 FT SEAS WILL SHIFT W THROUGH WED NIGHT AND
PERSIST THROUGH THU.

GAP WINDS...

GULF OF TEHUANTEPEC...THE NEXT PULSE OF N TO NE WINDS IN THE
GULF OF TEHUANTEPEC IS EXPECTED TO BEGIN LATE WED NIGHT WITH
WINDS PEAKING AT 30 KT EARLY THU. WINDS ARE EXPECTED TO REMAIN
AT 20 TO 25 KT...LOCALLY 30 KT UNTIL THE NEXT GALE FORCE GAP
WIND EVENT ARRIVES FRI NIGHT INTO SAT AS A REINFORCING PUSH OF
COLD AIR OCCURS ACROSS THE WESTERN GULF OF MEXICO.

GULF OF PAPAGAYO...STRONG TO GALE FORCE EASTERLY TRADE WIND FLOW
ACROSS THE SW CARIBBEAN SEA IS RESULTING IN PULSES OF STRONG
EASTERLY GAP WINDS THROUGH THE GULF OF PAPAGAYO THAT WILL PULSE
DURING THE OVERNIGHT HOURS THROUGH SAT. THE CARIBBEAN WINDS WILL
ALSO SEND 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