000
AXPZ20 KNHC 012158
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI JAN 01 2016

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...

THE PRESSURE GRADIENT BETWEEN A HIGH PRESSURE RIDGE BEHIND A
STATIONARY FRONT OVER THE GULF OF MEXICO AND LOWER PRESSURE IN
THE VICINITY OF THE EASTERN NORTH PACIFIC ITCZ IS HELPING TO
FUNNEL GALE FORCE WINDS OVER THE GULF OF TEHUANTEPEC. 1540 AND
1626 UTC ASCAT PASSES CAPTURED THE AREA OF 30 TO 35 KT WINDS
QUITE WELL AND ALLOWED A BETTER DEFINITION OF THE INITIAL AREA
OF GALES IN THE HIGH SEAS FORECAST. THESE GALE FORCE WINDS ARE
FORECAST TO CONTINUE THROUGH EARLY MON. SEAS ARE EXPECTED TO
BUILD TO 12 TO 15 FT RANGE TONIGHT INTO EARLY SAT. 

A COLD FRONT CURRENTLY W OF THE AREA WILL SWEEP INTO THE NW
WATERS LATER TONIGHT TO ALONG 130W BY LATE SAT. DEEPENING LOW
PRESSURE BEHIND THE FRONT WILL TIGHTEN THE PRESSURE GRADIENT
OVER THE AREA N OF 27N W OF 135W BY LATE SAT WITH WINDS
INCREASING TO GALE FORCE...30 TO 35 KT INTO SAT NIGHT AND SUN.
THIS SYSTEM WILL ALSO HELP TO USHER IN A NEW SET OF NW SWELLS
WITH COMBINED SEAS REACHING 20 FT SAT NIGHT OVER THE FAR NW
PORTION OF THE AREA. 
 
SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS 
MIAHSFEP2/FZPN03 KNHC FOR MORE DETAILS ON BOTH GALE AREAS.

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

THE ITCZ EXTENDS FROM 04.5N89W TO 05N122W TO 02N135W TO BEYOND
03N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 90 NM N
OF ITCZ BETWEEN 120W AND 124W. 

...DISCUSSION... 

WEAK HIGH PRESSURE OF 1021 MB CENTERED NEAR 30N123W EXTENDS A
RIDGE SE TO NEAR 19N110W. THERE IS A WEAK PRESSURE GRADIENT OVER
THE FORECAST AREA WITH MAINLY MODERATE TO LOCALLY FRESH TRADES
PREVAILING N OF THE ITCZ TO 20N. RECENT ALTIMETER PASSES
INDICATE SEAS TO 9 FT COVERING THE AREA S OF 13N BETWEEN 115W
AND 128W WINDS IN NW AND S SWELL. SEAS GREATER THAN 8 FT WILL
SHRINK OVER THIS AREAS OVER THE NEXT 24 HOURS.
THE PRESSURE GRADIENT WILL REMAIN WEAK WITH WINDS EXPECTED TO
REMAIN BELOW FORECAST CRITERIA THROUGH THE NEXT COUPLE OF DAYS. 

GAP WINDS...STRONG TO GALE FORCE TRADES ACROSS THE SW CARIBBEAN
SEA ARE RESULTING IN STRONG TO NEAR GALE NE TO E GAP WINDS
THROUGH THE GULF OF PAPAGAYO WITH SEAS REACHING 11 FT. STRONG
GAP WINDS WILL CONTINUE OVER THE GULF OF PAPAGAYO OVER THE NEXT
COUPLE OF DAYS...WITH WINDS ONCE AGAIN REACHING NEAR GALE FORCE
EARLY SAT MORNING. NE SWELL GENERATED FROM THIS GAP WIND EVENT
WILL PROPAGATE EASTWARD AND MERGE WITH NE SWELL GENERATED BY THE
GULF OF TEHUANTEPEC EVENT WITH AN AREA OF 8 FT SEAS GENERALLY
FROM 06N TO 10N BETWEEN 88W AND 100W. THE WINDS ARE FORECAST TO
TEMPORARILY DROP BELOW 20 KT BY LATE SUN BEFORE PULSING TO 20
TO 25 KT OVERNIGHT.
  
THE STRONG WINDS IN THE CARIBBEAN 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 TONIGHT AND SAT. 

$$
COBB