000
AXPZ20 KNHC 010330
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT MAY 01 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 08N96W TO 05N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 180 NM EITHER SIDE OF 
A LINE FROM 04N92W TO 06N105W TO 05N116W. SCATTERED MODERATE 
CONVECTION NOTED WITHIN 90 NM EITHER SIDE OF A LINE FROM 06N121W 
TO 04N138W.

...DISCUSSION...

A LONGWAVE UPPER TROUGH DOMINATES THE WESTERN CONUS WITH ITS 
MEAN AXIS EXTENDING INTO THE DISCUSSION AREA ALONG 32N114W TO A 
BASE NEAR 22N115W. UPPER MOISTURE SPREADING SE INTO THE TROUGH 
OVER THE AREA N OF 30N BETWEEN 120W AND 140W SEEM TO EVAPORATE 
BEFORE REACHING ALONG 30N. OTHERWISE...THE UPPER LEVELS ARE DRY 
N OF 18N ACROSS THE ENTIRE AREA. OVER THE NEXT FEW DAYS AN UPPER 
SHORTWAVE TROUGH IS EXPECTED PASS THROUGH THE LONGWAVE PATTERN 
EFFECTIVELY AMPLIFYING THE LONGWAVE TROUGH SW FROM ARIZONA TO 
NEAR 09N133W.

AN UPPER ANTICYCLONE IS QUASI STATIONARY NEAR 13N84W WITH AN 
UPPER RIDGE EXTENDING W ACROSS THE TROPICAL PACIFIC THROUGH 
07N117W TO A SHARP CREST AT 08N142W. ITCZ CONVECTION HAS BEEN 
ENHANCED UNDER THE ENTIRE UPPER RIDGE ESPECIALLY BETWEEN 80W AND 
115W. THE RESULTANT DEBRIS MOISTURE FROM CONVECTION BETWEEN 120W 
AND 140W IS ADVECTED NE...BUT FOR THE MOST PART EVAPORATES 
COMPLETELY BY THE TIME IT REACHES ALONG 18N IN THE SOUTHERLY 
SINKING DRY AIR ACCOMPANYING UPPER TROUGH PREVIOUSLY DESCRIBED. 
DEBRIS MOISTURE FROM THE ITCZ CONVECTION ENHANCED BETWEEN 80W 
AND 120W IS FANNING OUT OVER THE AREA WITH SOME OF THE DEBRIS 
MOISTURE SPREADING SW ACROSS THE EQUATOR WHILE SOME OF THE 
MOSITURE IS ADVECTED NE ACROSS THE NW CARIBBEAN. 

ELSEWHERE AT THE SURFACE...
A RIDGE IS BECOMING STATIONARY FROM 32N140W TO NEAR 12N110W. 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 E OF 
THE RIDGE REACH THE WESTERN BAJA PENINSULA AND HAVE INCREASED 
20 TO 30 KT WITH SEAS HEIGHTS TO ABOUT 16 FT ALONG 29N NEAR 
120W. SOUTHERLY WINDS CONTINUE AROUND THE SOUTHERN TIP OF THE 
BAJA PENINSULA OVER THE GULF OF CALIFORNIA TO ABOUT 27N...WITH 
SEAS TO 7 FT IN REFRACTIVE SWELL OVER THE SOUTHERN GULF WATERS. 
THESE NW SWELLS SHOULD REACH THE DEEP TROPICS SAT AND EVENTUALLY 
MIX WITH A NEW SERIES OF LONG PERIOD SW SWELL CROSSING THE 
EQUATOR ON SUN. THE SOUTHERLY MONSOON FLOW OVER THE FAR SE 
WATERS HAS DIMINISHED BELOW 20 KT AND SEAS HAVE ALSO SUBSIDED TO 
ABOUT 7 FT. CURRENTLY A SURFACE TROUGH EXTENDS FROM 13N94W TO 
07N88W. SCATTERED MODERATE ISOLATED STRONG CONVECTION EXISTS 
WITHIN ABOUT 150 NM OF 11N91W.
   
$$
NELSON