000
AXPZ20 KNHC 030328
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU DEC 03 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 
0300 UTC.

...ITCZ...
THE ITCZ AXIS IS ALONG 07N77W TO 08N91W TO 09N105W TO 07N114W TO 
09N119W TO 07N126W TO 06N140W. ISOLATED MODERATE CONVECTION 
WITHIN 90 NM OF AXIS BETWEEN 98W AND 100W. NUMEROUS MODERATE TO 
SCATTERED STRONG CONVECTION WITHIN 100 NM EITHER SIDE OF AXIS 
BETWEEN 113W AND 122W. SCATTERED MODERATE CONVECTION WITHIN 180 
NM N OF AXIS AND 60 NM S OF AXIS BETWEEN 126W AND 133W.

...DISCUSSION...
SURFACE HIGH PRESSURE 1017 MB NEAR 27N131W CONTINUES TO WEAKEN. 
WITH THE WEAKENING OF THE SURFACE HIGH PRESSURE...THE FRESH 
TRADEWINDS CONTINUE TO DECREASE IN COVERAGE...AND ARE MAINLY 
FROM 09N TO 21N W OF 114W. ANOTHER SHORTWAVE TROUGH...CURRENTLY 
W OF THE AREA ALONG 142W IS EXPECTED TO PASS ACROSS THE N 
PORTION OF THE FORECAST AREA...N OF 21N...THU NIGHT THROUGH SAT. 
THIS WILL FURTHER WEAKEN THE SURFACE HIGH PRESSURE AND DECREASE 
THE COVERAGE OF FRESH TRADES. 

LONG PERIOD NW SWELL CONTINUES ACROSS MOST OF THE AREA W OF 
110W...MIXING WITH NE SWELL IN THE AREA OF TRADES...AND WITH 
CROSS-EQUATORIAL SE SWELL S OF ABOUT 10N. 

FURTHER EAST...WINDS IN THE GULF OF PAPAGAYO ARE EXPECTED TO 
REMAIN AT OR NEAR 20 KT DUE TO FRESH TRADES FUNNELING THROUGH 
FROM THE SW CARIBBEAN. THESE WINDS WILL BE STRONGEST IN THE 
MORNING HOURS WITH THE AID OF DRAINAGE FLOW. 

NORTHERLY FLOW IS EXPECTED TO INCREASE OVER THE GULF OF 
CALIFORNIA N OF 27N LATE THU AS HIGH PRES BUILDS OVER THE GREAT 
BASIN.

$$
AL