000
AXPZ20 KNHC 140348
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU MAY 14 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 
0315 UTC.

...ITCZ...

THE ITCZ AXIS IS ALONG POINTS 07N77W TO 07N86W TO 09N99W TO 
04N120W TO 05N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS NOTED WITHIN 150 NM OF LINE FROM 09N79W TO 06N90W 
TO 11N103W TO 07N107W TO 12N114W.

...DISCUSSION...

ALOFT...AN UPPER CYCLONE IS NEAR 23N136W WITH A TROUGH E TO 
ANOTHER CYCLONE AT 22N122W. A BROAD UPPER TROUGH IS ALONG 
32N102W TO 29N126W. AN UPPER ANTICYCLONE IS CENTERED NEAR 
29N134W SURROUNDED BY UPPER MOISTURE WITHIN 150 NM OF ITS 
CENTER. OTHERWISE DRY UPPER AIR IS INDICATED N OF 15N W OF
116W AND ALONG THE TROUGH N OF 28N BETWEEN 116W AND 102W. 

A SECOND UPPER ANTICYCLONE IS NEAR 12N99W WITH A RIDGE EXTENDING 
N NE TO OVER SE LOUISIANA. AN UPPER RIDGE EXTENDS W ACROSS 
VENEZUELA AND COLOMBIA OVER THE TROPICAL E PACIFIC TO A SHARP 
CREST AT 10N80W. AN BROAD UPPER TROUGH EXTENDS SW ACROSS THE NW 
CARIBBEAN ALONG 20N80W TO 09N90W SEPARATING THE FLOW ASSOCIATED 
WITH THE TWO ANTICYCLONES. UPPER DIFFLUENCE IS ENHANCING 
CONVECTION ALONG THE ITCZ BETWEEN 94W AND 112W WITH THE DEBRIS 
MOISTURE ADVECTED N OVER OLD MEXICO BETWEEN 94W AND 104W AND 
SPILLING OVER THE UPPER LEVELS OF THE GULF OF MEXICO W OF 87W. 
CONVECTION ALONG THE ITCZ IS ALSO ENHANCED E OF 86W WITH MOST OF 
THE DEBRIS MOISTURE SPREADING NE ACROSS COSTA RICA AND PANAMA 
AND THE S CENTRAL CARIBBEAN TURNING E AND CONTINUING E ACROSS 
THE ENTIRE E CARIBBEAN INTO THE SUBTROPICAL CENTRAL ATLC.
       
AT THE LOW LEVELS...A RIDGE EXTENDS SE ALONG 32N135W TO 17N105W. 
NORTHERLY WINDS TO 20 KT ARE NE OF THE RIDGE AXIS OVER THE AREA 
N OF 25N BETWEEN 125W AND 116W. THE GRADIENT IS EXPECTED TO 
TIGHTEN FURTHER INCREASE THE N WINDS TO 20 TO 25 KT WITH SEAS 
BUILDING TO A MAX OF 13 FT LATE THU WITH CONDITIONS SPREADING S 
TO ALONG 22N ON FRI THEN DIMINISHING SOME ON FRI. A SMALL AREA 
OF NE TRADES TO 20 KT ARE OBSERVED S OF THE RIDGE FROM 09N TO 
15N W OF 125W AND EXPECTED TO DIMINISH THU.      

GULF OF PAPAGAYO GAP...NE WINDS IN THE W CARIBBEAN ARE EXPECTED 
TO SURGE THROUGH THE GULF OF PAPAGAYO AT 15 TO 20 KT LATE 
TONIGHT THEN DIMINISH ON LATE MORNING THU.

$$
NELSON