000
AXPZ20 KNHC 050325
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED MAY 05 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 
0300 UTC.

...ITCZ...
AXIS ALONG 09N84W TO 05N96W TO 04N120W TO 05N140W.  SCATTERED 
MODERATE CONVECTION WITHIN 120 NM OF AXIS E OF 88W AND WITHIN 60 
NM OF AXIS W OF FROM 114W-129W.

...DISCUSSION...
SHARP UPPER LEVEL TROUGH EXTEND FROM 32N121W TO 00N124W WITH A 
10 DEG SWATH OF DRY AIR MASS CENTERED ALONG AXIS.  UPSTREAM 
RIDGE WITH CREST ALONG 130W ADVECTING MINOR AMOUNTS OF MOISTURE 
RIDING OVER ITS CREST W OF AXIS.  JET CORE 80-90 KT RIDING OVER 
BROAD DOWNSTREAM ANTICYCLONE CENTERED AT 21N99W PRACTICALLY 
COVERS REMAINDER OF BASIN WITH DRY STABLE AIR MASS N OF ITCZ... 
EXCEPT FOR SECOND TROUGH ALOFT EXTENDING FROM NICARAGUA TO 
02N94W.  SMALL AREA OF DIFFLUENT UPPER LEVEL FLOW JUST SE OF 
SECOND TROUGH ENHANCES DEEP ITCZ CONVECTION E OF 88W.  E-NE FLOW 
AROUND SOUTHERN PERIPHERY OF RIDGE IS HOSTILE TO DEVELOPMENT OF 
WEAK SURFACE TROUGH EMBEDDED IN ITCZ FROM 02N106W TO 10N106W... 
ALTHOUGH CONDITIONS BECOME MORE FAVORABLE FURTHER W AS TROUGH 
APPROACHES 117W.  TROUGH PRESENTLY ASSOCIATED WITH SCATTERED 
MODERATE CONVECTION WITHIN 120 NM E OF AXIS.  

ELSEWHERE AT THE SURFACE...
WEAK DISSIPATING COLD FRONT ALONG 32N E OF 130W INCREASING 
ONSHORE WINDS TO FRESH BREEZE FLOW JUST N OF 28N AND EXPECTED TO 
EXPAND S OF 26N E OF 130W BY THU.  MODERATE N SWELLS SPREAD S OF 
23N.  

LARGE SURFACE RIDGE CENTERED N OF AREA IS DOMINANT FEATURE 
ACROSS E PAC N OF ITCZ.  MODEL GUIDANCE SOLUTIONS MAINTAIN FRESH 
NE TRADES N OF 08N W OF 130W EXPANDING IN AREA BY THU. 

$$
WALLY BARNES