000
AXPZ20 KNHC 251542
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON MAY 25 2009

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 
1515 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 102W FROM 04N TO 16N MOVING W AT 15 KT. 
ALTHOUGH CONVECTION IS CONCENTRATED ALONG THE ITCZ...SLIGHT 
CYCLONIC TURNING IS NOTED ALONG THE WAVE AXIS AT 09N.

...ITCZ...

THE ITCZ AXIS EXTENDS ALONG 09N83W TO 09N105W TO 11N117W TO 
05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
WITHIN 150 NM EITHER SIDE OF A LINE FROM 05N77W TO 09N86W TO 
06N91W TO 12N113W AND AND ALSO WITHIN 60 NM EITHER SIDE OF A 
LINE FROM 14N123W TO 06N134W TO 05N140W.

.DISCUSSION...

ALOFT...AN UPPER LEVEL SHORTWAVE TROUGH EXTENDS SW ALONG 32N118W 
TO 24N131W AND IS ACCOMPANIED BY DRY AIR WITHIN 120 NM EITHER 
SIDE OF ITS AXIS. A SECOND UPPER TROUGH IS NOTED ALONG 21N105W 
TO 16N120W TO 10N130W TO A SMALL UPPER CYCLONE OVER THE EQUATOR 
AT 129W. A RIDGE EXTENDS E INTO THE DISCUSSION AREA ALONG 
06N140W TO 03N133W. A TROPICAL MID TO UPPER LEVEL ANTICYCLONE IS 
AT 08N87W WITH A RIDGE W TO A SHARP CREST AT 12N116W AND A RIDGE 
E TO 10N85W.

SOME UPPER MOISTURE IS NOTED FROM 19N TO 24N W OF 114W. UPPER 
DIFFLUENCE HAS ENHANCED CONVECTION ALONG THE ITCZ BETWEEN 120W 
AND 140W WITH SOME OF THE MOISTURE SPREADING NE TO NEAR 16N113W.
CONVECTION IS ALSO ENHANCED ALONG THE ITCZ E OF 110W WITH THE 
DEBRIS MOISTURE ADVECTED E OF THE UPPER TROUGH ACROSS THE 
CARIBBEAN.

.AT THE LOW LEVELS...A RIDGE EXTENDS SE ALONG 32N133W TO 12N115W.
NE TRADES S OF THE RIDGE...FROM 07N TO 22N W OF 123W...ARE IN 
THE 15 TO 20 KT RANGE WITH SEAS TO 8 FT. A SMALL AREA OF N 
SWELLS TO 8 FT ARE EXPECTED TO CONTINUE OVER THE DISCUSSION AREA 
N OF 27N BETWEEN 118W AND 125 W FOR A FEW DAYS.  

$$
NELSON