000
AXPZ20 KNHC 232117
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

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

MONSOON TROUGH EXTENDS 08N83W TO 07N85W. ITCZ CONTINUES FROM 
07N85W TO 09N125W TO 07N140W. SCATTERED MODERATE CONVECTION IS 
NOTED WITHIN 90 NM N OF AXIS BETWEEN 125W AND 130W.

...DISCUSSION...

GAP WINDS...
GULF OF TEHUANTEPEC...THE MAIN FORECAST ISSUE CONTINUES TO BE 
STRONG WINDS IN THE GULF OF TEHUANTEPEC...REACHING GALE FORCE 
TONIGHT. 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.  
LOOKING AHEAD...THE HIGH PRES N OF THE AREA WEAKENS THROUGH 
SUN...ALLOWING WINDS BELOW GALE FORCE THROUGH TEHUANTEPEC BY 
MON. 

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.

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. THIS FEATURE MAY BE 
STARTING TO BECOME ORGANIZED ON SATELLITE IMAGERY ALONG THE ITCZ 
NEAR 07N93W.

1028 MB HIGH PRES IS CENTERED N OF AREA NEAR 33N131W WITH A 
RIDGE COVERING ROUGHLY THE AREA N OF 18N W OF 115W. GENTLE TO 
MODERATE BREEZES ARE 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 AS THE SWELL DECAYS. ON THE SOUTHERN PERIPHERY 
OF THE RIDGE...SCATTEROMETER DATA FROM 19 UTC INDICATED NE-E 
TRADES 20-25 KT FROM 10N TO 20N W OF 128W. A PAIR OF ALTIMETER 
PASSES SHOWED SEAS OF 8-11 FT IN MIXED NW AND NE SWELL. 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. 

$$
CHRISTENSEN