000
AXPZ20 KNHC 291559
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE APR 29 2008

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 
1500 UTC.

...ITCZ...
ITCZ AXIS IS ALONG THE LINE...07N78W TO 08N85W TO 08N102W TO 
07N128W TO 04N140W. SCATTERED MODERATE TO STRONG CONVECTION 
WITHIN 240 NM S OF AXIS BETWEEN 83W AND 95W. SCATTERED MODERATE 
CONVECTION WITHIN 180 NM EITHER SIDE OF AXIS BETWEEN 115W AND 
135W.

...DISCUSSION...

E OF 110W...GALE FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC 
WILL DIMINISH THROUGH THIS AFTERNOON...WITH GENERALLY LIGHT TO 
MODERATE WINDS BY LATE WED...AS SURFACE HIGH PRES N OF THE AREA 
IN THE GULF OF MEXICO EXITS FURTHER EAST. FURTHER SOUTH...SHIP 
OBSERVATIONS SUPPORT QUIKSCAT DATA SHOWING 20 TO 25 KT FLOW 
THROUGH THE GULF OF PAPAGAYO. WHILE TRADE WIND FLOW OVER THE 
CARIBBEAN REMAINS RELATIVELY MODEST...THE QUIKSCAT DATA HINTED 
OF WEAK CYCLONIC TURNING WEST OF COSTA RICA. ALOFT...WEAK 
MID/UPPER TROUGHING PUSHING EAST THROUGH MEXICO AND CENTRAL 
AMERICA...TO THE NORTH OF A BROAD ANTICYCLONE OVER COLOMBIA. SW 
FLOW BETWEEN THE RIDGE AND TROUGHS IS ENHANCING CONVECTION ALONG 
THE ITCZ NE OF THE GALAPAGOS. MEANWHILE WAVE MODELS SHOW 18 
SECOND SWELL UP TO SIX FEET OUT OF THE SOUTHWEST MOVING TOWARD 
THE MEXICAN AND CENTRAL AMERICAN PACIFIC COASTS BY LATE WED.

W OF 110W...AN UPPER TROUGH EXTENDING FROM BRITISH COLUMBIA TO 
29N137W CONTINUES TO SHIFT EASTWARD TOWARD THE CALIFORNIA 
COAST...FLATTENING OUT AN UPPER RIDGE N OF 20N. A 1035 MB 
SURFACE HIGH NEAR 37N147W WILL BUILD EASTWARD BEHIND THE UPPER 
TROUGH...MAINTAINING STRONG NORTHERLY FLOW AND ASSOCIATED SWELL 
ON ITS EASTERN PERIPHERY ALONG THE CALIFORNIA COAST...REACHING 
AS FAR SOUTH AS THE NORTHERN BAJA COAST THROUGH 48 HOURS. FRESH 
TRADES ALSO PERSIST OVER THE NEXT COUPLE OF DAYS ON THE SOUTHERN 
EDGE OF THE SURFACE HIGH. FURTHER SOUTH...AN ELONGATED UPPER 
TROUGH REMAINS IN PLACE FROM 04N110W TO 10N140W...WITH A 
PARALLEL UPPER RIDGE FROM 06N110W TO 25N140W. DIVERGENT FLOW 
ALOFT BETWEEN THESE FEATURES IS ENHANCING CONVECTION ALONG THE 
ALONG ITCZ W OF 110W. MEANWHILE A SURGE OF SW SWELL OF UP TO 8 
FT WITH 16 SECOND PERIODS IS PUSHING NORTHWARD ACROSS THE 
EQUATOR MAINLY BETWEEN 110W AND 130W. 


$$
CHRISTENSEN