000
AXPZ20 KNHC 091508
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JAN 9 2013

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 04N77W TO 08N90W THEN ITCZ GOES TO 
07N110W TO 06N140W. SCATTERED MODERATE CONVECTION EXISTS FROM 
130W TO 135W WITHIN 180 NM N OF AXIS. 

...DISCUSSION...
A VIGOROUS COLD FRONT WILL BE PUSHING INTO THIS AREA ALONG THE 
NORTHERN BORDER THIS EVENING.  THE FRONT IS SUPPORTED BY A 
SUBSTANTIAL AND DIGGING UPPER TROUGH FROM 40N140W TO 35N146W TO 
30N152W OBSERVED IN THE WATER VAPOR IMAGERY THIS MORNING. THE 
COLD FRONT MAY PROGRESS AS FAR AS 20N BY SATURDAY BEFORE 
DISSIPATING.  AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT...THE 
ENHANCED GRADIENT WILL BOOST THE NE TRADEWINDS SIGNIFICANTLY UP 
TO NEAR GALE CONDITIONS BY THURSDAY MORNING IN THE NORTHWEST 
AREA.  NONE OF THE GLOBAL MODELS ARE EXPLICITLY CALLING FOR GALE 
CONDITIONS TO OCCUR NOR DO ANY OF THE GFS ENSEMBLES.  WHILE THE 
NE TRADES SHOULD DIMINISH SOMEWHAT ON SATURDAY...THEY ARE LIKELY 
TO BE AT FRESH TO STRONG BREEZE CONDITIONS THROUGH THE MIDDLE OF 
NEXT WEEK.  ACCOMPANYING THE COLD FRONT AND NEAR GALE TRADEWINDS 
ARE A MIX OF LONG PERIOD NW SWELL AND SHORT PERIOD NE WIND 
WAVES.  THESE SHOULD PEAK WITH SIGNIFICANT WAVE HEIGHTS UP TO 15 
FT IN THE WESTERN PORTION OF AREA ON SATURDAY AND SUNDAY BEFORE 
SLOWLY DIMINISHING.  THE FORECAST IS A BLEND OF THE SOMEWHAT 
LESS AGGRESSIVE GFS-BASED WAVEWATCH AND THE MORE AGGRESSIVE 
WAVEWATCH FROM NOGAPS...UKMET...AND ECMWF.

AS THE FRONT PASSES THROUGH THE NORTHERN GULF OF CALIFORNIA LATE 
THURSDAY AND EARLY FRIDAY...A BRIEF PERIOD OF STRONG BREEZE OR 
NEAR GALE CONDITIONS WILL OCCUR. THE WINDS WILL VEER FROM SW 
EARLY THURSDAY NIGHT TO W LATE THURSDAY TO NW BY EARLY FRIDAY. 
CONDITIONS SHOULD DIMINISH BY LATE FRIDAY.

A WEAK GULF OF PAPAGAYO GAP WIND EVENT IS CURRENTLY OCCURRING 
WITH PEAK NE TO E WINDS OF FRESH TO STRONG BREEZE CONDITIONS.  
AS IS TYPICAL...WINDS AND SEAS ARE LOWER DURING THE AFTERNOON 
AND EARLY EVENING HOURS.  THE PAPAGAYO GAP WINDS SHOULD CONTINUE 
THROUGH SATURDAY BEFORE DIMINISHING ON SUNDAY.

NO SIGNIFICANT GULF OF TEHAUNTEPEC GAP WIND EVENTS ARE 
ANTICIPATED FOR THE NEXT SEVERAL DAYS.

$$
LANDSEA