000
AXPZ20 KNHC 132145
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI JAN 13 2012

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 
2100 UTC.

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

THE MONSOON TROUGH AXIS EXTEND FROM 07N78W TO 05N107W. THE ITCZ 
AXIS EXTEND FROM 05N107W TO BEYOND 06N140W. SCATTERED MODERATE 
CONVECTION WAS NOTED WITHIN 210 NM S OF AXIS E OF 82W. SCATTERED 
MODERATE CONVECTION WAS NOTED WITHIN 60 NM OF AXIS BETWEEN 87W 
AND 92W. 

...DISCUSSION...

A DEEP LAYERED LOW 1016 MB IS CENTERED AT THE SURFACE NEAR 
28N132W. 1026 MB HIGH PRESSURE IS CENTERED NEAR 42N136W. THIS IS 
RESULTING IN ONLY A WEAK PRESSURE GRADIENT AND MODERATE TO FRESH 
WINDS N OF THE SURFACE LOW. THE LOW IS FORECAST TO WEAKEN TO A 
TROUGH WITHIN THE NEXT 24-30 HRS. OTHERWISE...THE PRESSURE 
GRADIENT OVER THE LOCAL FORECAST AREA W OF 110W IS WEAK...WITH 
WINDS BELOW 20 KT.

LARGE NW SWELLS RESULTING IN SEAS UP TO 11 FT ARE PRESENT OVER 
THE NW PART OF THE AREA. THESE SWELLS ARE FORECAST TO SPREAD 
SLOWLY SE WHILE GRADUALLY SUBSIDING OVER THE NEXT 36 HOURS.

GAP WINDS...
STRONG HIGH PRESSURE 1035 MB OVER THE GREAT BASIN REGION IS 
PROVIDING A PRESSURE GRADIENT TO PRODUCE FRESH TO STRONG NW 
WINDS OVER THE GULF OF CALIFORNIA. THE AREA OF HIGH PRESSURE IS 
EXPECTED TO WEAKEN OVER THE NEXT 24 HOURS WHICH WILL LOOSEN THE 
PRESSURE GRADIENT AND DIMINISH WINDS BELOW 20 KT BY SAT 
AFTERNOON. 

STRONG HIGH PRES BUILDING ACROSS THE GULF OF MEXICO BEHIND A 
COLD FRONT HAS TIGHTENED THE PRES GRADIENT OVER SOUTHERN MEXICO. 
THIS HAS INDUCED GALE FORCE NLY WINDS INTO THE GULF OF 
TEHUANTEPEC WITH WINDS OF UP TO 40 KT. THESE WINDS WILL DIMINISH 
SLIGHTLY BY SAT AFTERNOON...BUT REMAIN AT MINIMAL GALE FORCE 
THROUGH AT LEAST SUN AFTERNOON.

FRESH NLY WINDS TO 20 KT FROM THE SW CARIBBEAN WILL FUNNEL INTO 
THE GULF OF PAPAGAYO THROUGH AT LEAST SUN AFTERNOON.

FRESH TO STRONG TRADEWINDS ARE FUNNELING THROUGH THE GAPS IN 
TOPOGRAPHY OF NICARAGUA AND COSTA RICA INTO THE GULF OF 
PAPAGAYO. THIS WILL MAINTAIN THROUGH AT LEAST SUNDAY AFTERNOON. 
WINDS WILL BE HIGHEST DURING THE EARLY MORNING HOURS WITH THE 
ADDED COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS. 

$$
AL