000
AXPZ20 KNHC 040343
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU DEC 04 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 7N78W 6N90W 
7N102W 7N112W 9N123W 7N140W. SCATTERED MODERATE CONVECTION IS
WITHIN 120 NM S OF THE AXIS BETWEEN 120W-125W...AND WITHIN 60 NM
N OF THE AXIS E OF 86W.

...DISCUSSION...

HIGH PRES OVER MEXICO HAS WEAKENED OVER MEXICO WITHIN THE LAST 
12 HOURS AND WINDS OVER THE GULF OF TEHUANTEPEC HAVE DIMINISHED
SUBSTANTIALLY...AND ARE PRESENTLY NE AROUND 20 KT. NOAA 
WAVEWATCH GUIDANCE SUGGESTS RESIDUAL WAVE HEIGHTS OF UP TO 9 FT 
IN THE GULF OF TEHUANTEPEC. AS LOW PRES EXITS THE SOUTHERN 
PLAINS OVER THE 12-18 HOURS...WINDS ARE EXPECTED TO GRADUALLY 
INCREASE ONCE AGAIN THROUGH THE GULF OF TEHUANTEPEC REACHING 
MINIMAL GALE FORCE IN ABOUT 30 HOURS AS STRONG HIGH PRES BUILDS 
SWD ONCE AGAIN INTO SOUTHERN TEXAS AND MEXICO. THIS EVENT SHOULD 
LAST THROUGH LATE FRI NIGHT BEFORE SUBSIDING.

DOWNWIND OF THE GULF OF PAPAGAYO...QUIKSCAT DATA FROM THIS 
MORNING CONFIRMED THE PRESENCE OF NE 20 TO 25 KT WINDS WITHIN 
ABOUT 60 NM EITHER SIDE OF 10.5N E OF 88.5W. A BROADER AREA OF 
15 TO 20 KT WINDS SURROUNDS THIS AREA...RUNNING GENERALLY FROM 
08N TO 12N E OF 91W. THE SURFACE RIDGE EXTENDING INTO THE 
WESTERN CARIBBEAN SUSTAINING THIS EVENT WILL WEAKEN SLOWLY OVER 
THE NEXT 24-48 HOURS...HOWEVER THE WINDS THERE ARE EXPECTED TO 
CONTINUE THROUGH FRI MORNING...THEN WEAKEN SOME BEFORE 
INCREASING AGAIN ON SAT AS JUST LIKE THE GULF OF TEHUANTEPEC
...STRONG SURFACE HIGH PRES BUILDING SWD INTO MEXICO WILL ALLOW 
FOR WINDS DOWNWIND OF THE GULF OF PAPAGAYO TO INCREASE. NOAA 
WAVEWATCH GUIDANCE INDICATES SEAS OF 8 TO 10 FT OVER MUCH OF THE 
ABOVE AREA...WITH NE SWELL LIKELY SPREADING FARTHER W OVER THE 
NEXT DAY OR TWO BEFORE DECAYING FURTHER.

ELSEWHERE...A BAND OF ENHANCED TRADES EXISTS FROM 08N TO 15N W 
OF 125W...A RESULT OF STRONGER THAN AVERAGE SUBTROPICAL RIDGING 
JUST NW OF THE AREA. GLOBAL MODELS SUGGEST THAT ASSOCIATED PARENT
HIGH CENTER OF 1030 MB N OF THE AREA NEAR 34N137W WILL SHIFT WSW 
OVER THE NEXT 48 HOURS ALLOWING FOR THE TRADES TO WEAKEN...AND 
BE CONFINED TO THE FAR W PART OF THE AREA AT THAT TIME. AT THE 
TIME NOAA WAVEWATCH GUIDANCE SHOWS SEAS OF 8-11 FT OVER MUCH OF 
THE WESTERN PORTION OF THE AREA THROUGH 24 HOURS...BUT SUBSIDING 
TO 8 FT BY FRI AFTERNOON.

WATER VAPOR IMAGERY SHOWS A BROAD AREA OF UPPER LEVEL DIFFLUENCE
COVERING THE AREA FROM 7N TO 15N BETWEEN 124W AND 137W...AND IS
ENHANCING ITCZ CONVECTION W OF 120W. WELL PRONOUNCED CUT-OFF
UPPER LEVEL W OF THE AREA NEAR 16N1465 IS FORECAST TO BE ABSORBED
INTO AN UPCOMING UPPER LEVEL LOW THAT DROPS SW INTO THE NW CORNER
OF THE AREA FRI NIGHT. THIS WILL MAINTAIN AN UPPER LEVEL RIDGE 
PATTERN IN PLACE OVER MUCH OF THE AREA THROUGH SAT AS THE LOW 
STAYS OVER THE FAR WESTERN PORTION.

$$
AGUIRRE