000
AXPZ20 KNHC 282158
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED APR 28 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 
2045 UTC.

...ITCZ...

AXIS ANALYZED FROM 10N84W TO 05N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED N OF 05N E OF 88W...WITHIN 
60 NM EITHER SIDE OF A LINE FROM 08N99W TO 04N108W TO 
06N127W...AND ALSO WITHIN 30 NM EITHER SIDE OF A LINE FROM 
04N133W TO 05N140W.

...DISCUSSION...

A LONGWAVE UPPER TROUGH HAS ITS MEAN AXIS EXTENDING INTO THE 
DISCUSSION AREA ALONG 32N115W TO 22N105W. UPPER MOISTURE IS 
NOTED N OF 30N E OF 120W AND SPREADING E ACROSS THE NORTHERN 
BAJA PENINSULA AND SOUTHERN ARIZONA AND NEW MEXICO. OTHERWISE 
THE UPPER LEVELS ARE DRY N OF 22N W OF 99W.

AN UPPER ANTICYCLONE IS OVER EL SALVADOR AT 13N88W WITH AN UPPER 
RIDGE EXTENDING W ACROSS THE TROPICAL PACIFIC ALONG 12N110W TO 
08N138W. ITCZ CONVECTION HAS BEEN ENHANCED UNDER THE RIDGE E OF 
126W WITH THE RESULTANT DEBRIS MOISTURE ADVECTED NE ACROSS THE 
RIDGE TO ALONG 22N...WHERE SOME OF THE MOISTURE EVAPORATES IN 
THE DRY AIR ACCOMPANYING UPPER TROUGH. HOWEVER A THIN BAND OF 
MOISTURE DOES CONTINUE EASTWARD ACROSS CENTRAL OLD MEXICO AND 
THE GULF OF MEXICO EVENTUALLY CROSSING OVER THE STATE OF 
FLORIDA. SOME OF THE MOISTURE ALSO SPREADS S FROM THE ITCZ 
CROSSING THE EQUATOR E OF 100W...AND SOME OF THE MOISTURE IS 
ALSO ADVECTED NE ACROSS CENTRAL AMERICA.

ELSEWHERE AT THE SURFACE...
A COLD FRONT IS LOSING IDENTITY FROM 32N116W TO 24N140W. 
NORTHERLY WINDS ACCOMPANYING THE FRONT HAVE ALREADY VEERED TO 
THE NE OVER THE WATERS N OF 20N W OF 130W. NORTHERLY WINDS AT 15 
TO 20 KT ARE NOTED ELSEWHERE N OF 20N W OF THE BAJA PENINSULA 
AND EXPECTED TO INCREASE TO 20 TO 25 KT OVER MOST OF THE AREA N 
OF 18N OVER THE THE NEXT FEW DAYS. ASSOCIATED NW SWELLS WILL 
PROPAGATE SE INTO THE AREA AND CONTINUE SE REACHING THE DEEP 
TROPICS BY THE WEEKEND. A SOUTHERLY MONSOON TROUGH IS DEVELOPING 
OVER THE FAR SE WATERS FROM 07N82W TO 04N88W WITH WINDS 
INCREASING TO 20 TO 25 KT WITHIN ABOUT 180 NM SE OF THE TROUGH 
AXIS.        

$$
NELSON