000
AXPZ20 KNHC 101005
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAY 10 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...
AXIS ALONG 05N77W TO 08N86W TO 09N109W TO 05N116W TO 07N130W TO 
07N140W.  ISOLATED MODERATE CONVECTION WITHIN 240 NM OF AXIS E 
OF 105W.  SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM 
OF AXIS FROM 110W TO 120W.  SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 120 NM OF AXIS E OF 130W.

...DISCUSSION...
UPPER LEVEL CYCLONIC CIRCULATION AT 22N118W REMAINS BLOCKED FROM 
MOVING E BY LARGE ANTICYCLONE AT 14N100W.  BETWEEN BOTH THESE 
FEATURES A BROAD SWATH OF DEEP LAYER MOISTURE IS ADVECTED NE 
INTO MEXICO WHERE THERMAL TROUGH TURNS IT INTO CONVECTION WITH 
THE HELP OF DAYTIME HEATING.  MOISTURE SWATH CONTINUES INTO 
CENTRAL TEXAS FEEDING COLD FRONT MOVING SE.

AT THE SURFACE...
QUICKLY WEAKENING HIGH PRES CENTER 1028 MB AT 34N135W FORCED E 
BY APPROACHING COLD FRONT NOW ALONG 145W.  THIS DECREASES AREA 
COVERAGE OF TRADE WINDS TO W OF 135W AND EVENTUALLY WEAKENS 
TRADES BELOW 20 KT WITHIN 24 HRS.  GALE FORCE WINDS N OF 32N HAS 
ALSO DIMINISH AND N SWELLS ENCROACHING INTO E PAC SUBSIDE 
GRADUALLY THROUGH NEXT TWO DAYS.  

WEAK LOW PRES SURFACE TROUGH FROM 11N110W TO 04N115W ATTRACTING 
FRESH SE-S WINDFLOW ALONG WITH MODERATE SWELL TRAINS OBSERVED 
S OF 06N FROM 107W TO 130W.  TROUGH WEAKENS AND SWELLS SUBSIDE 
WITHIN 24 HRS.  
 
GAP WINDS...RETURN OF STRONG TRADE WINDS IN WRN CARIBBEAN 
PROMPTED BY 1008 MB LOW PRES OVER COLOMBIA ALLOW FOR ELY FLOW TO 
SEEP THROUGH NRN COSTA RICA AND SRN NICARAGUA INTO GULF OF 
PAPAGAYO...WITH FRESH BREEZE BEGINNING LATER TODAY. 

$$
WALLY BARNES