000
AXPZ20 KNHC 051546
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN DEC 05 2010

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE AXIS FROM 08N79W TO 06N90W TO LOW 
PRES NEAR 08N105W TO 09N125W TO 07N140W. SCATTERED MODERATE 
WITHIN 90 NM OF AXIS BETWEEN 121W AND 125W. 

...DISCUSSION...

W OF 110W...
A 0618 UTC ASCAT PASS SHOWED 20 TO 30 KT WESTERLY FLOW ON THE S 
SIDE OF A 998 MB GALE CENTERED N OF THE AREA NEAR 35N131W. THE 
LOW WAS TURNING NE WITH A DEVELOPING REINFORCING COLD FRONT 
THAT EXTENDED THROUGH 30N130W TO 25N140W. A SHIP OBSERVATION 
FROM SHIP WITH CALL SIGN ZCDA9 LOCATED NEAR 27N137W AT 1200 UTC 
INDICATED NW WINDS OF 35 KT...HOWEVER A QUALITY CONTROL OF THE 
SHIP DATA REVEALED THAT THE WINDS WERE ABOUT 10 KT TOO HIGH. THE 
SHIP ALSO REPORTED SEAS OF 14 FT WHICH CONFIRMED THE PRESENCE OF 
LONG PERIOD NW SWELL ENTERING THE AREA FROM THE N CENTRAL 
PACIFIC. GLOBAL MODELS SHOW ADDITIONAL SWELL TO 18 FT FROM 25N W 
OF 125W. FURTHER SOUTH...TRADES CONTINUE S OF THE BOUNDARY...W 
OF 135W. THE LOW PRES WILL SHIFT E AND WEAKEN N OF THE AREA. AS 
A RESULT...THE STRONGER WINDS WILL REMAIN N OF 25N...AND 
DIMINISH THROUGH 48 HOURS. THE ACCOMPANYING SWELL WILL ALSO 
SUBSIDE...BUT MORE SLOWLY OVER THE NEXT SEVERAL DAYS AS IT 
SHIFTS S. 

MEANWHILE LOW PRES CURRENTLY ALONG THE ITCZ NEAR 08N105W WILL 
MOVE W ALONG THE ITCZ BECOMING A TROUGH ALONG 120W BY 72 HOURS. 
AN EARLIER ASCAT PASS SHOWED WINDS TO 20 KT WITHIN 90 NM OF THE
LOW...IN PART AIDED BY FRESH WINDS ORIGINATING OUT OF THE GULF 
OF TEHUANTEPEC. THESE WINDS WILL PERSIST THROUGH THE NEXT COUPLE 
OF DAYS AS THE LOW MOVES S OF HIGH PRES OFF NORTHERN BAJA. SEAS 
WILL STAY AROUND 8 FT IN THE AREA OF 20 KT WINDS...THEN SUBSIDE 
BY 72 HOURS AS THE LOW WEAKENS.

STRONGLY DIFFLUENT UPPER FLOW FROM 10N TO 20N W OF 130W WAS 
AIDING IN THE DEVELOPMENT OF AN AREA OF SCATTERED MODERATE 
CONVECTION TO THE W OF A SURFACE TROUGH NOW LOCATED ALONG 
15N126W TO 08N127W. THIS TROUGH IS FORECAST TO MOVE BENEATH THIS 
AREA OF DIFFLUENT FLOW AND IS FORECAST TO AMPLIFY ON MON WITH AN 
AREA OF NE WINDS OF 20 KT DEVELOPING AHEAD OF THE TROUGH.  

E OF 110W...
THE MAIN ISSUE WILL BE GALE FORCE WINDS FUNNELING INTO THE GULF 
OF TEHUANTEPEC OVERNIGHT TONIGHT AS A COLD FRONT MOVES THROUGH 
THE SW GULF OF MEXICO TO THE NORTH. WINDS ARE FORECAST TO REACH 
40 KT WITH SEAS BUILDING TO 15 FT BY MON. FURTHER SOUTH...20 KT 
WINDS WILL PULSE THROUGH THE GULF OF PAPAGAYO...MAINLY IN THE 
OVERNIGHT HOURS DUE TO DRAINAGE INFLUENCES. A 06Z ASCAT 
CONFIRMED THIS PATTERN WAS SETTING UP. GLOBAL MODELS SHOW IT 
PERSISTING OVER THE NEXT COUPLE OF DAYS.

$$
COBB