000
AXPZ20 KNHC 292213
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU APR 29 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...ITCZ...

AXIS ANALYZED FROM 10N85W TO 05N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 60 NM OF 07N80W...AND 
WITHIN 90 NM EITHER SIDE OF A LINE FROM 08N87W TO 04N94W TO 
07N103W...AND WITHIN 30 NM OF 05N110W...AND WITHIN 90 NM 
06N123W...AND WITHIN 30 NM EITHER SIDE OF A LINE FROM 05N129W TO 
06N140W.

...DISCUSSION...

A LONGWAVE UPPER TROUGH DOMINATES THE WESTERN CONUS WITH ITS 
MEAN AXIS EXTENDING INTO THE DISCUSSION AREA ALONG 32N117W TO 
18N103W. UPPER MOISTURE IS NOW SPREADING SE INTO THE TROUGH OVER 
THE AREA N OF 30N BETWEEN 130W AND 140W. OTHERWISE THE UPPER 
LEVELS ARE DRY N OF POINTS 17N140W TO 22N130W TO 12N110W TO 
13N96W.

AN UPPER ANTICYCLONE IS ESTIMATED NEAR 11N78W WITH AN UPPER 
RIDGE EXTENDING W ACROSS THE TROPICAL PACIFIC ALONG 07N120W TO
09N140W. ITCZ CONVECTION HAS BEEN ENHANCED UNDER THE ENTIRE 
UPPER RIDGE. THE RESULTANT DEBRIS MOISTURE FROM CONVECTION 
BETWEEN 110W AND 140W S ADVECTED NE BUT FOR THE MOST PART 
EVAPORATES IN THE DRY AIR ACCOMPANYING UPPER TROUGH PREVIOUSLY 
DESCRIBED. ITCZ CONVECTION IS ALSO ENHANCED E OF 110W AND IN THE 
AREA FROM 10N TO 13N WITHIN 180 NM W OF COAST CENTRAL AMERICA. 
ALTHOUGH SOME OF THE DEBRIS MOISTURE FROM ALL OF THIS CONVECTION 
IS ADVECTED S OF THE EQUATOR E OF 110W...MOST OF THE DEBRIS 
MOISTURE IS ADVECTED NE IN A PLUME THAT COVERS THE W CARIBBEAN 
AND THEN TURNS E ACROSS THE SOUTHEY GULF OF MEXICO AND S FLORIDA.

ELSEWHERE AT THE SURFACE...
A RIDGE IS BECOMING STATIONARY FROM 32N140W TO NEAR 12N110W. 
NE TRADES SO THE RIDGE ARE AT 15 TO 20 KT. SEAS 8 TO 11 FT IN 
NEW NE SWELL MIXING WITH LONG PERIOD NW SWELL. NORTHERLY WINDS 
TO THE NE OF THE RIDGE NOW REACH THE BAJA PENINSULA RANGE FROM 
15 TO 25 KT WITH SEAS HEIGHTS EXPECTED TO BUILD TO ABOUT 17 FT 
ALONG 29N NEAR 118W BY LATE FRI. THESE NW SWELLS SHOULD REACH 
REACH THE DEEP TROPICS BY THE WEEKEND. SOUTHERLY MONSOON FLOW 
OVER THE FAR SE WATERS IS AT 20 TO 25 KT BUT EXPECTED TO 
GRADUALLY DIMINISH OVER THE NEXT FEW DAYS.
   
$$
NELSON