000
AXPZ20 KNHC 240917
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAY 24 2009

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.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 90W FROM 03N-13N MOVING W AT AROUND 10 
KT. CONVECTION ASSOCIATED WITH THE WAVE HAS DIMINISHED SINCE 
YESTERDAY AS IT LOST ITS PREVIOUS UPPER-LEVEL SUPPORT. 
CURRENTLY...SATELLITE IMAGERY ONLY SHOWS ISOLATED SHOWERS AND 
TSTMS EITHER SIDE OF THE WAVE AXIS.  
 
...ITCZ...
THE ITCZ AXIS IS ALONG 08N78W TO 15N111W TO 10N122W TO 06N140W. 
SCATTERED MODERATE ISOLATED STRONG FROM 07N TO 13N BETWEEN 102W 
AND 111W...AND WITHIN 120 NM S OF AXIS FROM 118W TO 122W.   

SCATTERED TO ISOLATED STRONG WITHIN 150 NM OF THE COAST OF 
COLOMBIA FROM 03N TO 05N. SIMILAR CONVECTION IS NOTED ALONG THE 
COAST OF WESTERN PANAMA...AND NEAR THE BORDER OF COSTA RICA AND 
NICARAGUA. 

.DISCUSSION...
WESTERLY ZONAL FLOW CONTINUES TO DOMINATE THE FORECAST AREA N OF 
20N. AN UPPER-LEVEL RIDGE ALONG 10N-12N COVERS MOST OF THE 
REGION E OF 125W. THE RIDGE REACHES SE MEXICO AND N CENTRAL 
AMERICA. W OF THE RIDGE...THERE IS A SHORT-WAVE TROUGH EXTENDING 
ALONG 16N130W 11N132W 08N133W. ABUNDANT MID/UPPER LEVEL MOISTURE 
IS OBSERVED WITHIN THE RIDGE WHILE A NEW SWATH OF MOISTURE IS 
ENTERING THE NW PORTION OF THE FORECAST AREA AHEAD OF A STRONG 
UPPER-LEVEL TROUGH/LOW LOCATED W OF 140W. 

AT THE SURFACE...A 1030 MB HIGH PRES CENTER LOCATED WELL N OF 
AREA EXTENDS A RIDGE SE TO 20N115W. SOUTH OF THE RIDGE...A PAIR 
OF 1011 MB LOW PRES CENTERS REMAIN. ONE IS NEAR 12N127W. PRES 
GRADIENT BETWEEN THE RIDGE AND THE LOW IS PRODUCING NE WINDS OF 
20 KT WITH 8 FT SEAS WITHIN 420 NM NW QUADRANT OF LOW. A QSCAT 
PASS FROM AROUND 0330 UTC CONFIRMED THESE WIND SPEEDS. SATELLITE 
IMAGERY REVEALS A SWIRL OF LOW CLOUDS ASSOCIATED WITH THIS LOW 
FORECAST TO DISSIPATE IN ABOUT 24 HOURS. 

THE SECOND SFC LOW IS SITUATED NEAR 15N113W. SHOWERS AND 
THUNDERSTORMS ASSOCIATED WITH THE AREA OF DISTURBED WEATHER  
REMAIN DISORGANIZED...AND UPPER-LEVEL WINDS ARE BECOMING LESS 
CONDUCIVE FOR TROPICAL DEVELOPMENT. WINDS OF 20 KT AND SEAS OF 8 
FT ARE STILL FOUND WITHIN 120 NM N SEMICIRCLE OF LOW CENTER.

LONG PERIOD N SWELLS ARE GRADUALLY SPREADING ACROSS THE N WATERS 
MAINLY N OF 27N BETWEEN 120W AND 134W. SHIP 3FXY2 LOCATED NEAR 
28N120W AT 0600 UTC IS REPORTING COMBINED SEAS OF 9 FT. 

$$
GR