000
AXPZ20 KNHC 290313
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI MAY 29 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 
0330 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 90W/91W FROM 04N-13N MOVING W AT 10 TO 15 
KT. SCATTERED MODERATE CONVECTION IS NOTED WHERE THE WAVE AXIS 
MEETS THE ITCZ. THIS WAVE IS ASSOCIATED WITH A MAXIMUM IN DEEP 
LAYER MOISTURE BASED ON TOTAL PRECIPITABLE WATER PRODUCT FROM 
CIMSS. THE WAVE COULD ENCOUNTER MORE FAVORABLE UPPER-LEVEL 
CONDITIONS AS IT CONTINUES TO PROGRESS ACROSS THE E PACIFIC 
REGION DURING THE NEXT DAY OR SO...AND A LOW PRES MAY FORM ALONG 
THE WAVE AXIS DURING THE UPCOMING WEEKEND.

...ITCZ...
THE ITCZ AXIS IS ALONG 06N78W TO 10N89W TO 09N110W TO 10N118W TO 
04N140W. A CLUSTER OF SCATTERED MODERATE TO STRONG CONVECTION IS 
N OF 05N E OF 83W INCLUDING THE GULF OF PANAMA. SCATTERED 
MODERATE CONVECTION IS FROM 06N TO 12N BETWEEN 90W AND 101W... 
AND WITHIN 100 NM S OF AXIS FROM 102W TO 127W.

...DISCUSSION...
A WEAK SURFACE RIDGE EXTENDS SOUTHWARD INTO THE NORTHERN WATERS 
FROM A 1018 MB SURFACE HIGH LOCATED N OF THE AREA NEAR 36N131W. 
GENERALLY LIGHT WINDS DOMINATE THE REGION N OF 18N AND W OF 115W 
UNDER THE INFLUENCE OF THIS RIDGE. THE HIGH WILL MOVE FURTHER 
SOUTH INTO THE FORECAST WATERS AS A COLD FRONT APPROACHES THE NW 
CORNER OF THE DISCUSSION AREA. S TO SW WINDS OF 20 KT WILL BE 
FOUND AHEAD OF THE FRONT WHICH IS EXPECTED TO ENTER THE NW 
PORTION AROUND 0900 UTC FRI. LONG PERIOD SWELL FROM THE NW WILL 
FOLLOW THE FRONT...RAISING SEAS TO 12 FT SAT MORNING. A 
WEAKENING SURFACE TROUGH IS ANALYZED ALONG 13N123W 08N128W 
03N131W. A FEW SHOWERS ARE EITHER SIDE OF TROUGH AXIS. 

ALOFT...AN UPPER-LEVEL LOW LOCATED NEAR 32N123W HAS A WEAK 
TROUGH EXTENDING SWD TO NEAR 12N120W. AN UPPER-LEVEL HIGH 
CENTERED NEAR 05N136W EXTENDS A RIDGE EWD AND IS HELPING TO 
INDUCE CONVECTION ALONG THE ITCZ. A SECOND UPPER-LEVEL 
ANTICYCLONE IS NEAR 11N94W WITH A BROAD RIDGE COVERING SE MEXICO 
AND CENTRAL AMERICA TO THE COAST OF COLOMBIA. THIS RIDGE IS 
SUPPORTING THE STRONG CONVECTION OVER THE GULF OF PANAMA. 
 
$$
GR