000
AXPZ20 KNHC 020319
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN MAY 02 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0245 UTC.

...ITCZ...

AXIS ANALYZED FROM 10N86W TO 05N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED FROM 03N TO 10N BETWEEN 82W 
AND 85W CURRENTLY DECREASING IN INTENSITY AND COVERAGE...AND 
FROM 02N TO 08N BETWEEN 90W AND 100W AND DIMINISHING WITH TIME 
...AND DISSIPATING WITHIN ABOUT 90 NM OF 05N116W AND 04N127W.
 
...DISCUSSION...

A POSITIVE TILT LONGWAVE UPPER TROUGH DOMINATES THE WESTERN 
CONUS WITH ITS MEAN AXIS EXTENDING INTO THE DISCUSSION AREA FROM 
32N105W TO A BASE NEAR 12N113W. UPPER MOISTURE CONTINUES TO 
SPREAD SE INTO THE TROUGH OVER THE DISCUSSION AREA BETWEEN 108W 
AND 140W...BUT ALMOST COMPLETELY EVAPORATES ALONG 30N. 

ALTHOUGH A LONGWAVE RIDGE IS NOW DOMINATING THE EASTERN PACIFIC 
IT REMAINS JUST W OF 140W OVER AREA TO THE S OF 30N. AN UPPER 
ANTICYCLONE IS QUASI STATIONARY NEAR 17N87W WITH AN UPPER RIDGE 
EXTENDING WSW TO A SHARP CREST AT 07N136W. ITCZ CONVECTION HAS 
BEEN ENHANCED UNDER THE ENTIRE UPPER RIDGE...ESPECIALLY BETWEEN 
80W AND 110W. A LOW LEVEL TROUGH HAS BEEN APPEARING 
INTERMITTENTLY FOR THE PAST FEW DAYS OVER THE PACIFIC WATERS 
ALONG THE COAST OF CENTRAL AMERICA BUT SEEMS TO HAVE FILLED LATE 
THIS AFTERNOON AND CONVECTION IS NOW ENHANCED WELL INLAND OVER 
GUATEMALA AND OLD MEXICO. RESULTANT DEBRIS MOISTURE FROM THIS 
CONVECTION AND ITCZ CONVECTION E OF 105W... IS ADVECTED S OF THE 
EQUATOR E OF 106W...AND ALSO ADVECTED NE ACROSS CENTRAL AMERICA 
TO THE W OF 87W. SOME OF THE DEBRIS MOISTURE FROM ITCZ 
CONVECTION BETWEEN 110W AND 140W SPREADS NE BUT EVAPORATES 
BEFORE REACHING 15N. THE UPPER LEVELS ARE VERY DRY N OF 16N 
ACROSS THE ENTIRE AREA. OVER THE NEXT FEW DAYS THE LONGWAVE 
TROUGH WILL SHIFT E TO OVER CENTRAL N AMERICA AND THE LONGWAVE 
RIDGE WILL SHIFT E WITH ITS S TO N AXIS E OF 140W BY TUE.

ELSEWHERE AT THE SURFACE...
A RIDGE AXIS IS MEANDERING FROM 32N132W TO NEAR 08N110W. NE 
TRADES THE S OF THE RIDGE AXIS ARE AT 15 TO 20 KT...WITH SEAS 8 
TO 11 FT IN MIXED NE AND NW SWELL. NORTHERLY WINDS TO THE NE OF 
THE RIDGE AXIS REACH TO 115W AT 15 TO 20 KT...BUT ARE STILL 
ACCOMPANIED BY SEAS HEIGHTS TO 13 FT IN NW SWELL. SOUTHERLY 
WINDS CONTINUE AROUND THE SOUTHERN TIP OF THE BAJA PENINSULA
TO BANDERAS BAY.

THE SOUTHERN EXTENT OF THESE NW SWELLS IS CURRENTLY ABOUT THE 
LATITUDE OF THE ITCZ W OF 115W WITH THE NW SWELLS EXPECTED TO 
REACH ALONG 100W BY LATE SUN. A NEW SERIES OF SOUTHERLY SWELLS 
WILL REACH THE EQUATOR TONIGHT NEAR 120W. THE NW AND SW SWELLS 
WILL MIX THROUGHOUT THE TROPICAL WATERS EARLY NEXT WEEK. 
   
$$
NELSON