000
AXPZ20 KNHC 130946
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED MAY 13 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 08N83W TO 07N96W TO 09N113W TO 04N135W TO 04N140W.  
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM OF 
AXIS E OF 102W AND WITHIN 60 NM OF 13N114W.

...DISCUSSION...
UPPER TROUGH FROM 32N136W TO UPPER CYCLONE AT 25N136W THEN TO  
06N125W PREVENTED FROM FURTHER EASTWARD DRIFT BY BROAD UPPER 
LEVEL RIDGE CENTERED AT 15N100W.  ABUNDANT UPPER MOISTURE 
ADVECTED AROUND TROUGH BASE AND TURNED NE BY RIDGE TOWARDS 
SOUTHERN BAJA CALIFORNIA AND N HALF OF MEXICO.  DRY UPPER AIR 
WITHIN 240 NM OF TROUGH AXIS.  THERMAL LOW PRES OVER CENTRAL 
MEXICO FEEDING ON TROPICAL MOISTURE CONTINUES DEVELOPING DEEP 
CONVECTION DURING MAXIMUM DAYTIME HEATING...THEN ABATE IN 
EVENING HOURS. 

ITCZ CONTINUES BEING SUPPLIED MOISTURE BY RIDGE OVER SOUTH 
AMERICA BECOMING MORE ACTIVE E OF 102W ENHANCED BY A MORE 
PRONOUNCED EQUATORIAL TROUGH.     

AT THE SURFACE...
WEAKENING HIGH PRES 1027 MB AT 38N130W HAS RIDGE EXTEND TO 
15N105W PRODUCING SMALL AREA OF FRESH N-NW TRADES ALONG COAST OF 
CALIFORNIA AND ENCROACHING INTO E PAC N OF 25N E OF 125W.  
SWELLS FROM GALE FORCE WINDS WELL N OF AREA SPREAD S INTO E PAC 
THROUGH 48 HRS.       

GULF OF PAPAGAYO GAP...FRESH NE TRADES IN W CARIBBEAN SEEP 
THROUGH GULF OF PAPAGAYO WITH HELP OF LATE NIGHT DOWNSLOPE 
MOUNTAIN DRAINAGE DIMINISHING AS SEA BREEZE DEVELOPS IN LATE 
MORNING AND AFTERNOON.  CONDITIONS EXPECTED TO WEAKEN WED.

$$
WALLY BARNES