000
AXPZ20 KNHC 242147
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT NOV 24 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 
2115 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 09N83W TO 08N96W. THE ITCZ 
AXIS LIES FROM 08N101W TO 08N115W TO 07N125W TO 09N140W. 
SCATTERED MODERATE CONVECTION WITHIN 60 NM EITHER SIDE OF AXIS 
BETWEEN 95W AND 105W.
 
...DISCUSSION...

GULF OF TEHUANTEPEC...NORTHERLY GALE WINDS ARE CONTINUING 
DOWNWIND OF THE GULF OF TEHUANTEPEC. SHIP 9V8798 REPORTED 33 KT 
NEAR 14N95W AT 1200 UTC. SCATTEROMETER DATA FROM 19 UTC 
INDICATED WINDS TO GALE FORCE AS WELL. THE PRESSURE GRADIENT 
OVER THE AREA IS EXPECTED TO GRADUALLY WEAKEN OVER THE NEXT TWO 
DAYS AS THE HIGH PRES OVER THE BAY OF CAMPECHE DIMINISHES AND A 
SURFACE TROUGH S OF THE GULF OF TEHUANTEPEC MOVES WESTWARD. 
EXPECT THE WINDS TO DIMINISH BELOW GALE FORCE BY SUN AFTERNOON. 
ANOTHER COLD FRONT WILL PUSH INTO THE GULF OF MEXICO ON 
TUE...ALLOWING ANOTHER SURGE TO GALE FORCE AGAIN ON TUE NIGHT. 

GULF OF PAPAGAYO...LINGERING RIDGING FROM THE YUCATAN PENINSULA 
S TO NORTHERN NICARAGUA WILL KEEP THE PRESSURE GRADIENT TIGHT 
ENOUGH TO SUPPORT FRESH TO STRONG NE WINDS IN THE GULF OF 
PAPAGAYO THROUGH MON. SHIPS A8PQ8 AND 9V795 REPORTED 25 KT NE 
WINDS EARLIER TODAY UTC. WINDSAT DATA INDICATED THE PLUME OF 20 
TO 25 KT REACHING AS FAR DOWNSTREAM AS 12N91W. THESE CONDITIONS 
WILL CONTINUE WITH LITTLE CHANGE THROUGH SUN AND BEGIN TO SHRINK 
IN AREA BY MON AS THE HIGH PRESSURE OVER CENTRAL AMERICA WEAKENS.

THE COMBINED FLOW FROM TEHUANTEPEC AND PAPAGAYO GAP WIND EVENTS 
ARE SUPPORTING THE DEVELOPMENT OF TROUGHING ALONG 98W FROM 04N 
TO 11N. THIS FEATURE IS EXPECTED TO STRENGTHEN AS IT PROGRESSES 
WESTWARD ALONG THE ITCZ TO 101W SUN MORNING AND NEAR 105W MON 
MORNING...ENHANCING THE FRESH TO STRONG TEHUANTEPEC FLOW...AND 
MIXING WITH EASTERLY SWELL GENERATED DOWNSTREAM FROM THE 
PAPAGAYO AREA.

W OF 110W...A 1028 MB HIGH PRES AREA REMAINS STATIONARY NEAR 
34N132W...WITH SURFACE RIDGE EXTENDING TO 20N113W. A PAIR OF 
ALTIMETER PASSES FROM EARLIER THIS MORNING ADDED CONFIDENCE TO 
WAVE MODEL CONSENSUS SHOWING A BROAD AREA OF SEAS OF 8 TO 11 FT 
IN MIXED FRESH NE AND LONGER PERIOD NW SWELL...IN AN AREA OF 
FRESH TRADES FROM ROUGHLY 06N TO 22N W OF 115W. WAVE MODELS ARE 
ALSO IN BETTER AGREEMENT SHOWING SEAS N OF 22N HAVE SUBSIDED 
BELOW 8 FT. 

LOOKING AHEAD...OPERATIONAL AND ENSEMBLE MODEL GUIDANCE 
CONTINUES BE IN DECENT AGREEMENT SHOWING A A COLD FRONT 
APPROACHING THE FAR NW PORTION OF THE DISCUSSION AREA LATE 
MON...REACHING FROM 32N135W TO 24N140W BY EARLY TUE. THIS WILL 
INCREASE THE SOUTHERLY FLOW TO 20-25 KT ACROSS THE WATERS N OF 
24N W OF 135W. LONG PERIOD NW SWELL OF 10 TO 15 FT WILL FOLLOW 
THE FRONT. THE WINDS SUBSIDE THROUGH MID WEEK AS THE MAIN 
SUPPORTING ENERGY ALOFT LIFTS NE. WW3 GUIDANCE SHOWS THE LEADING 
EDGE OF NW SWELL WITH SEAS 8 FT OR GREATER TO PUSH THROUGH THE 
AREA N OF 10N AND W OF 110W THROUGH LATE WEEK...REACHING THE 
NORTHERN COAST OF BAJA BY EARLY FRI. ECWAVE GUIDANCE IS MUCH 
SLOWER AND LIMITS THE 8 FT OR GREATER NW SWELL TO AN AREA N OF 
15N W OF 120W BY LATE THU...THEN DECAYING AFTERWARD. GIVEN THE 
LONGER FETCH AND DURATION OF THE NEXT SWELL EVENT...THE FORECAST 
FAVORS THE MORE AGGRESSIVE WW3 GUIDANCE. 

$$
CHRISTENSEN