000
AXPZ20 KNHC 240339
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE NOV 24 2009

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 
0215 UTC.

...ITCZ...
AXIS ANALYZED FROM 08N81W TO 08N85W TO 06N91W TO 07N99W TO 
06N110W TO 07N118W TO 06N123W TO 09N136W TO 08N140W.  SCATTERED 
MODERATE CONVECTION WAS WITHIN 180 NM S OF AXIS E OF 87W.  
ISOLATED TO SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM OF 
AXIS FROM 104W TO 121W.

...DISCUSSION...
A BROAD MID-UPPER LEVEL RIDGE EXTENDED FROM 09N118W TO 30N129W 
IS MAINTAINING ANTICYCLONIC FLOW ACROSS BASIN N OF THE ITCZ AND 
W OF 122W...WHILE ADVECTING ABUNDANT TROPICAL MOISTURE WELL N OF 
ITCZ EASTWARD INTO CENTRAL MEXICO. A DIGGING S/W TROUGH EXTENDED 
FROM W TEXAS TO 20N105W AND HAS COME INTO PHASE WITH L/W TROUGH 
ACROSS THE CENTRAL U.S. SUBSIDENCE IS OCCURRING IN BROAD 
MID-UPPER CONVERGENCE ON BACK SIDE OF TROUGH ACROSS MOST OF NE 
PORTIONS OF THE AREA. AT THE BASE OF THIS TROUGH...UPPER LEVEL 
DIFFLUENT FLOW BETWEEN TROUGH AND RIDGE OVER SOUTH AMERICA WAS 
ENHANCING CONVECTION ACROSS THE W AND SW GULF OF MEXICO AS WELL 
AS THE W AND NW CARIBBEAN. THIS PATTERN WILL BE CHANGING DURING 
THE NEXT SEVERAL DAYS AS A SIGNIFICANT UPPER TROUGH S OF 30N AND 
JUST E OF THE HAWAII IS FORECAST TO MOVE E ACROSS THE FORECAST 
AREA AND BREAK DOWN THE RIDGE AXIS...WITH THE TROUGH EVENTUALLY 
REACHING THE BAJA PENINSULA AND INTENSIFYING BY EARLY THU.

...AT THE SURFACE...
HIGH PRES 1026 MB CENTERED AT 36N130W IS MAINTAINING FRESH TO 
STRONG TRADEWINDS ACROSS MUCH OF THE W HALF OF THE AREA...W OF 
120W N OF 10N...WITH SEAS 9 TO 12 FT IN MIXED NE AND NW SWELL. 
HIGH PRES WILL REMAIN N OF FORECAST AREA THROUGH NEXT 48 HOURS 
THEN SHIFT E-SE...BEFORE WEAKENING WED AND DIMINISHING... 
SHRINKING THE AREA OF FRESH TRADES.  THIS WILL ALSO BRING A 
TIGHTENING PRESSURE GRADIENT INTO GULF OF CALIFORNIA YIELDING A 
FRESH NORTH BREEZE TO THE BASIN N OF 28N BEGINNING EARLY TUE. 
LARGE LONG PERIOD NW SWELL CONTINUES TO SPREAD S AND SE ACROSS 
MOST OF THE EPAC W OF 115W. E OF 115W...SEAS WILL GENERALLY 
REMAIN 4 TO 6 FT IN A MERGING LONG PERIOD SW AND NW SWELL. 

FRESH NE TRADES THROUGH THE GULF OF PAPAGAYO AND DOWNSTREAM ARE 
EXPECTED TO DIMINISH BY 24 HOURS AS LOW PRES OVER COLOMBIA 
SHIFT W INTO THE SW CARIBBEAN...RESULTING IN A MORE N TO NE AND 
WEAKER FLOW OFF OF PAPAGAYO BY TUE NIGHT. NLY GAP WINDS THROUGH 
THE GULF OF TEHUANTEPEC ARE FORECAST TO BEGIN OVERNIGHT AND 
PULSE UP AND DOWN NEAR 20 KT THROUGH WED MORNING BEFORE 
BEGINNING TO INCREASE AND EXPAND IN AREAL COVERAGE AS ANOTHER 
FRONTAL SYSTEM SINKS S ACROSS THE GULF OF MEXICO. SOME MODELS 
ARE SUGGESTING POTENTIAL FOR GALE FORCE WINDS THROUGH 
TEHUANTEPEC BY 48 HOURS.   

$$
STRIPLING