000
AXPZ20 KNHC 052045
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED MAY 05 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 
2100 UTC.

...ITCZ...
AXIS ALONG 09N84W TO 06N97W TO 09N107W TO 04N125W TO 05N140W.  
ISOLATED MODERATE CONVECTION WITHIN 90 NM OF AXIS W OF 120W AND 
FROM 98W-102W.

...DISCUSSION...
SHARP UPPER LEVEL TROUGH OVER NW PORTION OF BASIN EXTENDS FROM 
32N125W TO 22N140W BRINGS MORE DRY AIR MASS INTO BASIN UNDER 
MODERATE SUBSIDENCE.  DOWNSTREAM UPPER LEVEL RIDGE CREST IS 
SQUEEZED BETWEEN SECOND TROUGH WITH AXIS ALONG 121W.  ONLY 
MOISTURE PATCH NOTED RIDES 100 KT JET CORE INTO NW MEXICO E OF 
SECOND TROUGH OVER CREST OF BROAD ANTICYCLONE CENTERED AT 18N98W 
WHICH IS DOMINANT FEATURE E OF 120W.  STRONG SUBSIDENCE UNDER 
ANTICYCLONE KEEPS REGION WITH VERY DRY STABLE AIR MASS N OF 
ITCZ.  

WELL DEFINED CYCLONIC VORTEX OVER WESTERN CARIBBEAN HAS TROUGH 
EXTEND TO 01N82W IN E PAC EFFECTIVELY CUTTING OFF MOISTURE 
INFLUX INTO ITCZ FROM SOUTH AMERICA.  EVEN SURFACE TROUGH 
EMBEDDED IN ITCZ...ONE ALONG 107W FROM 05N-11N AND THE SECOND 
ALONG 91W FROM 07N-11N...ARE ABLE TO GATHER MINOR MODERATE 
CONVECTION.

ELSEWHERE AT THE SURFACE...
BROAD BUILDING RIDGE CENTERED JUST N OF BASIN EXPECTED TO 
MAINTAIN MODERATE TO FRESH NE TRADES FROM N OF 08N W OF 130W AND 
FRESH TO STRONG NW BREEZE ALONG W COAST OF BAJA CALIFORNIA.  
MODERATE LONG PERIOD NE SWELLS PRODUCED BY GALE EVENT JUST N OF 
30N CROSS S INTO E PAC AND REACH 23N W OF 118W.  MODEL GUIDANCE 
IN AGREEMENT WITH STATUS QUO.

WEAK TROUGH ALONG 107W UNDER UNFAVORABLE ENVIRONMENT ALOFT NOT 
EXPECTED TO INTENSIFY WITHIN NEXT TWO DAYS.  SIMILARLY...TROUGH 
ALONG 91W WEAKENS QUICKLY AS DRY SUBSIDING AIR MASS ALOFT CHOKES 
IT.  NO CYCLONIC ORGANIZATION NOTED ON EITHER SYSTEM AND 
CONVECTION REMAINS CURTAILED.  

$$
WALLY BARNES