000
AXPZ20 KNHC 040931
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT DEC 04 2010

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 08N83W TO LOW PRES 
NEAR 08N98W TO 10N118W TO 08N140W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...

A DEEP LAYER TROUGH OVER THE FAR NW CORNER OF THE FORECAST AREA 
SUPPORTS A COLD FRONT THAT EXTENDS FROM 30N127W TO 25N130W TO 
16N140W. N TO NE WINDS OF 20 KT ARE NOTED W OF FRONT PER SHIP 
OBSERVATIONS AND AN EARLIER ASCAT PASS. SEAS ARE RANGING FROM 9 
TO 12 FT IN NW SWELL IN THE WAKE OF THE FRONT. SOUTHERLY WINDS 
OF 20 KT ARE ALSO NOTED N OF 28N E OF THE FRONT TO 125W. A 
DEEPENING LOW PRES WILL DIVE SOUTH TO NEAR 34N132W EARLY SUN 
MORNING AS A 1002 MB LOW. THE PROXIMITY OF THIS FEATURE WILL 
BRING AN INCREASE IN WINDS AND SEAS PARTICULARLY N OF 26N W OF 
125W. EXPECT W TO NW WINDS OF 20 TO 30 KT AND BUILDING SEAS TO 
AROUND 18 FT IN NW SWELL SAT NIGHT INTO SUN. THE LOW PRES WILL 
MOVE NE AND BE ABSORBED BY A STRONGER COLD FRONT WHICH IS 
FORECAST TO REACH THE NW PART OF THE DISCUSSION AREA BY TUE. 
ELSEWHERE...A 1020 MB HIGH CENTERED NEAR 22N118W IS EXPECTED TO 
WEAKEN OVER THE NEXT FEW DAYS AS THE AFOREMENTIONED COLD FRONT 
MOVES EASTWARD AND GRADUALLY DISSIPATES.  

FURTHER SOUTH...A 1010 MB LOW PRES IS CENTERED NEAR 08N98W 
DRIFTING WESTWARD. THIS SYSTEM IS TRIGGERING SOME DEEP 
CONVECTION AT TIMES WITH A SMALL AREA OF 20 KT WINDS WITHIN 90 
NM N SEMICIRCLE OF LOW CENTER. A SURFACE TROUGH REMAINS EMBEDDED 
WITHIN THE ITCZ ANALYZED FROM 14N117W TO 10N118W. GLOBAL MODELS 
SHOW THIS FEATURE PERSISTING WITHIN THE ITCZ THROUGH THE WEEKEND 
WHILE DRIFTING WESTWARD. WINDS ARE FORECAST TO INCREASE TO 20 KT 
AHEAD OF THE TROUGH AXIS LATE SUN NIGHT.

GAP WINDS...
CURRENTLY...WINDS ARE BELOW GALE FORCE THROUGH THE GULF OF 
TEHUANTEPEC. HOWEVER...A HIGH PRESSURE RIDGE WILL REMAIN OVER 
THE SW GULF OF MEXICO AND PORTIONS OF INTERIOR SOUTHERN MEXICO 
THROUGH MONDAY. THIS WEATHER PATTERN WILL RESULT IN N TO NE 
WINDS IN THE 20 TO 30 KT RANGE THROUGH THE FORECAST PERIOD.  
LOOKING AHEAD...A STRONG ARCTIC HIGH PRES ACROSS THE CENTRAL 
U.S. PLAINS IS FORECAST INVADE THE WESTERN GULF OF MEXICO BY 
MONDAY AND POSSIBLY DELIVER ANOTHER ROUND OF GALE FORCE WINDS TO 
THE TEHUANTEPEC REGION MONDAY NIGHT.

GAP WIND THROUGH THE GULF OF PAPAGAYO IS EXPECTED TO CONTINUE 
OVER THE NEXT 48 HOURS WITH NE WINDS PULSING TO 20 TO 25 KT AS 
HIGH PRES BUILDS OVER THE WESTERN CARIBBEAN. WINDS ARE NORMALLY 
GREATEST DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE 
ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW.

$$
GR