000
AXPZ20 KNHC 020942
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI MAY 02 2008

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 
0915 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 08N83W TO 07N91W TO 11N104W TO 
07N118W TO 08N128W TO 03N140W. SCATTERED MODERATE CONVECTION 
WITHIN 180 NM S OF AXIS BETWEEN 85W AND 89W. SCATTERED MODERATE 
CONVECTION WITHIN 240 NM N OF AXIS BETWEEN 123W AND 127W.

...DISCUSSION...

E OF 110W...UPPER ANTICYCLONE CENTERED NEAR 10N90W IS THE 
DOMINANT FEATURE ALOFT. ALTHOUGH THIS IS PROVIDING AMPLE UPPER 
DIVERGENCE OVER THE ITCZ...CONVECTION REMAINS RELATIVELY LIMITED 
DUE TO A FAIRLY LIGHT WIND REGIME AT THE SURFACE RESULTING IN 
WEAK CONVERGENCE. GLOBAL MODELS INDICATE THAT THE UPPER 
ANTICYCLONE WILL REMAIN IN ROUGHLY THE SAME PLACE THROUGH THE 
WEEKEND...AND LOW LEVEL WINDS WILL REMAIN FAIRLY LIGHT. THUS  
WHILE ASSOCIATED UPPER DIVERGENCE MAY ALLOW SMALL CLUSTERS OF 
MODERATE TO STRONG CONVECTION ALONG THE ITCZ THROUGH THE 
WEEKEND...LARGE SCALE CONVECTION MAY REMAIN STIFLED THROUGH SAT. 
THIS MAY CHANGE INTO SUNDAY HOWEVER AS AN UPPER TROUGH EXTENDS 
E-W ALONG 10N...THEN CUTS OFF NEAR 5N105W. BETTER DIVERGENCE ON 
THE EAST SIDE OF THIS NEW UPPER LOW MAY ALLOW MORE ORGANIZED 
CONVECTION NEAR 5N90W. GLOBAL MODELS SHOW VARIOUS WEAK SURFACE 
CIRCULATIONS IN THIS AREA INTO NEXT WEEK. FURTHER 
NORTH...SCATTEROMETER DATA FROM LATE THURSDAY SHOWS MODERATE NW 
FLOW OFF THE COAST OF MANZANILLO MEXICO. GFS AND EURO MODEL SHOW 
WINDS INCREASING SLIGHTLY OVER THE NEXT COUPLE OF DAYS BETWEEN 
HIGH PRESSURE TO THE WEST AND TROUGHING OVER MEXICO. MEANWHILE 
SOUTHWEST SWELL OF UP TO 6 FT WITH 18 SECOND PERIODS CONTINUES 
TO PUSH INTO THE MEXICAN AND CENTRAL AMERICAN COASTS...BEFORE 
TAPERING OFF BY SUNDAY.

W OF 110W...AN ELONGATED UPPER TROUGH EXTENDS FROM 30N135W TO 
15N130W TO 2N100W. THE PATTERN N OF 20N BECOMES MORE AMPLIFIED 
OVER THE NEXT COUPLE OF DAYS...WITH A BROAD UPPER RIDGE BUILDING 
ALONG 140W AND THE NORTHERN PORTION OF THE TROUGH DEEPENING 
ALONG ROUGHLY 125W. A 1028 MB SURFACE HIGH NEAR 32N135W SHIFTS 
SOUTHWEST AND DISSIPATES AHEAD OF AN APPROACHING FRONT 
ASSOCIATED WITH THE UPPER TROUGH. THIS ALLOWS FRESH TO STRONG N 
AND NE FLOW ON THE PERIPHERY OF THE SURFACE HIGH TO DIMINISH 
THROUGH SUN...LEAVING DECAYING NW SWELL TO 8 FT MOVING SOUTH 
DOWN THE CALIFORNIA COAST. FRESH TRADES PERSIST ON THE SOUTHERN 
SIDE OF SURFACE HIGH PRES BEHIND THE FRONT. DIVERGENCE ON THE 
SOUTHERN END OF THE TROUGH ALONG 125W COUPLES WITH STRONGER LOW 
LEVEL TRADE CONVERGENCE SOUTH OF THE SURFACE HIGH TO ENHANCE 
CLUSTERS OF CONVECTION ALONG THE ITCZ SAT INTO SUN W OF 120W.
$$
CHRISTENSEN