000
AXPZ20 KNHC 291551
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN APR 29 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
ITCZ AXIS ALONG...8N78W  9N98W  5N140W. 
ISOLATED MODERATE WITHIN 60 NM OF AXIS E OF 130W.  SCATTERED 
MODERATE ISOLATED STRONG WITHIN 90 NM OF AXIS W OF 130W.

...DISCUSSION...
E PAC WATERS UNDER STRONG MID TO UPPER LEVEL RIDGE WITH TWO MAIN 
CENTERS ONE AT 11N120W AND ANOTHER AT 10N85W.  WEAK JET STREAM 
85 KT CRESTING OVER FIRST CENTER ADVECTING PLENTY OF WATER ALOFT 
WHILE ANTICYCLONIC FLOW ADDS ITCZ CONVECTIVE DEBRIS TO WATER 
SWATH.  MOISTURE STILL REMAINS W OF 115W.  VERY DRY N OF 11N E 
OF 115W UNDER MODERATE TO STRONG SUBSIDENCE THROUGH CENTRAL 
AMERICA AND INTO GULF OF MEXICO AND CARIBBEAN SEA.   

SECOND ANTICYCLONE OVER COSTA RICA MAINTAINS STEADY E FLOW OF 
MOIST AIR MASS FROM SOUTH AMERICA INTO ITCZ BUT LACK OF UPLIFT 
MECHANISMS KEEPS CONVECTION ISOLATED MODERATE...BUT ADMITTEDLY 
INCREASING LAST 4-6 HRS. 

AT THE SURFACE  HIGH PRES CENTER 1028 MB WELL NW OF E PAC WILL 
MOVE E-SE AND WEAKEN NEXT 24 HRS. THIS WILL EFFECTIVELY DIMINISH 
TRADES WITH ONLY LINGERING AND ABATING NW SWELL REMAINING IN 
FORECAST WATERS.  

GAP WINDS...MINOR WIND EVENT AS E TRADES SPILL OVER CENTRAL 
AMERICA ALONG GULF OF PAPAGAYO REGION WITH 20 KT EXPECTED TO 
CONTINUE FOR NEXT 48 HRS.

$$
WALLY BARNES