000
AXPZ20 KNHC 231542
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI NOV 23 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

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

MONSOON TROUGH EXTENDS 09N78W TO 07N84W. ITCZ CONTINUES FROM 
07N84W TO 09N124W TO 07N140W. SCATTERED MODERATE CONVECTION IS 
NOTED FROM 06N TO 09N BETWEEN 99W AND 108W.

...DISCUSSION...

A 1026 MB HIGH PRES LOCATED N OF AREA NEAR 31N132W EXTENDS A 
RIDGE ACROSS TH N WATERS COVERING ROUGHLY THE AREA N OF 18N W OF 
115W. GENTLE TO MODERATE BREEZE IS NOTED UNDER THE INFLUENCE OF 
THIS RIDGE WITH COMBINED SEAS OF 8-10 FT IN PRIMARILY NW SWELL.  
THESE SEAS ARE EXPECTED TO SUBSIDE TO 5-7 FT ON SAT...AND 
FURTHER SUBSIDE TO 4-6 FT ON SUN. ON THE SOUTHERN PERIPHERY OF 
THE RIDGE...NE-E TRADES ARE AT 20-25 KT FROM 10N TO 20N W OF 
128W WITH SEAS OF 8-11 FT IN MIXED NW AND NE SWELL. 
SCATTEROMETER DATA CONFIRMED THE PRESENCE OF THESE FRESH TO 
STRONG WINDS. THE AERIAL EXTENT AND STRENGTH OF THE TRADES WILL 
DIMINISH AS HIGH PRES MOVES N AND AWAY FROM THE AREA WHILE 
WEAKENING BY SUN. 

LOOKING AHEAD...THE NEXT COLD FRONT IS FORECAST TO APPROACH THE 
FAR NW PORTION OF THE AREA BY LATE MON AND MOVE ACROSS THE NW 
WATERS BY TUE. EXPECT INCREASING SOUTHERLY WINDS OF 20-25 KT 
AHEAD OF THE FRONT...WITH BUILDING SEAS TO 8-12 FT IN THE WAKE 
OF THE FRONT WHICH IS EXPECTED TO REACH A POSITION FROM 31N135W 
TO 25N140W TUE MORNING. 

GLOBAL MODEL CONSENSUS CONTINUES TO SUGGEST A SURFACE LOW 
PRESSURE WILL DEVELOP WITHIN THE MONSOON TROUGH NEAR 06N96W ON 
SAT...AND MOVE W AT 15 KT FOR A FEW DAYS ACCOMPANIED BY 15-20 KT 
WINDS WITHIN 120 NM OVER THE N SEMICIRCLE.

GAP WINDS...
GULF OF TEHUANTEPEC...THE PRESSURE GRADIENT IS MAINTAINING 
NORTHERLY 20-30 KT WINDS IN AND DOWNSTREAM OF THE GULF OF 
TEHUANTEPEC. A REINFORCING NORTHERLY SURGE WILL PUSH THROUGH THE 
CHIVELA PASS AND INTO THE GULF OF TEHUANTEPEC TONIGHT BRINGING A 
NEW GALE FORCE WIND EVENT ACROSS THIS AREA. MARINE GUIDANCE 
SUGGEST THAT WINDS WILL INCREASE TO 30-40 KT AND MAY BE AS 
STRONG AS 45 KT. A GALE WARNING IS ALREADY IN EFFECT THROUGH 
EARLY SUN MORNING.   

GULF OF PAPAGAYO...NE-E 20-25 KT WINDS CONTINUE TO SURGE THROUGH 
A GAP IN THE CORDILLERA INTO AND DOWNSTREAM OF THE GULF OF 
PAPAGAYO TO NEAR 08N92W. THIS WEATHER PATTERN IS FORECAST TO 
PERSIST THROUGH 48 HOURS.

SCATTEROMETER DATA...FEW SHIP OBSERVATIONS AND VISIBLE SATELLITE 
IMAGERY CLEARLY INDICATE THE PRESENCE OF THESE TWO GAP WIND 
EVENTS...WITH ROPE CLOUDS DELINEATING THE LEADING EDGE OF THE 
CURRENT EVENTS. 

$$
GR