000
AXPZ20 KNHC 272205
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE APR 27 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 09N83W TO 05N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED FROM 03N TO 12N BETWEEN 83W 
AND 100W...AND ALSO FROM 04N TO 09N BETWEEN 120W AND 128W.  

...DISCUSSION...

A LONGWAVE UPPER TROUGH DOMINATES THE DISCUSSION AREA N OF 25N 
WITH AN EMBEDDED SHORTWAVE UPPER TROUGH...ORIGINATING FROM A 
CYCLONE OVER NORTHERN OLD MEXICO...EXTENDING SW INTO THE AREA TO 
A BASE AT 24N114W. UPPER MOISTURE IS NOTED WITHIN THE BROAD 
TROUGH...ROUGHLY N OF 27N BETWEEN 120W AND 130W. OTHERWISE THE 
UPPER LEVELS ARE DRY N OF 24N W OF 104W.

AN UPPER RIDGE EXTENDS W ACROSS THE TROPICAL PACIFIC ALONG 
11N83W TO 09N120W TO 09N137W. ITCZ CONVECTION WAS ENHANCED 
BETWEEN 105W AND 130W WITH THE DEBRIS MOISTURE ADVECTED NE 
ACROSS THE RIDGE TO ALONG 24N...WHERE MOST OF THE MOISTURE 
EVAPORATES...WITH ONLY A THIN BAND OF MOISTURE CONTINUING E 
ACROSS CENTRAL OLD MEXICO AND THE NW GULF OF MEXICO. CONVECTION 
IS ALSO ENHANCED OVER THE TROPICAL PACIFIC FROM 03N TO 12N E OF 
100W WHERE THE RESULTANT DEBRIS MOISTURE FANS OUT...WITH SOME OF 
THE MOISTURE CROSSING THE EQUATOR E OF 102W...AND SOME OF THE 
MOISTURE ADVECTED NE ACROSS CENTRAL AMERICA.

ELSEWHERE AT THE SURFACE...
A COLD FRONT IS LOSING IDENTITY FROM 32N128W TO 26N140W. NLY 
WINDS W OF THE FRONT WILL VEER TO THE NE TONIGHT INTO WED AS NW 
SWELLS PROPAGATE SE INTO THE AREA AND EVENTUALLY MERGE WITH 
CROSS EQUATORIAL SW SWELL IN THE DEEP TROPICS. THE PRESSURE 
GRADIENT WILL TIGHTEN WED NIGHT INTO FRI WITH NORTHERLY WINDS 
GRADUALLY INCREASING TO 20 TO 25 KT OVER MOST OF THE AREA N OF 
18N BY THU NIGHT. SOUTHERLY MONSOON WINDS WILL INCREASE TO 20 TO 
25 KT OVER THE AREA S OF 09N E OF 96W THROUGH THU.       

$$
NELSON