000
AXPZ20 KNHC 310316
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT JUL 30 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 11N85W TO 1007 MB LOW PRES AT 
10N99W TO 13N115W TO 10N122W TO 11N131W TO 09N140W.  SCATTERED 
MODERATE CONVECTION WITHIN 150 NM OF AXIS W OF 132W.  

...DISCUSSION...
LARGE AMPLITUDE UPPER LEVEL TROUGH ENTERS REGION AT 32N130W 
DIGGING SE FLATTENING CREST OF RIDGE CENTERED IN ANTICYCLONE  
AT 19N121W.  AREA N OF 16N W OF 110W REMAINS VERY DRY DUE TO 
MODERATE TO STRONG SUBSIDENCE CURTAILING ANY POSSIBLE 
CONVECTION.  ANTICYCLONE SQUEEZED SE BRINGING MODERATE NE-E WIND 
SHEAR OVER CONVECTION ALONG MONSOON TROUGH RESTRICTING ANY 
POSSIBLE DEEP CONVECTION ASSOCIATED WITH SURFACE LOW PRES 1008 
MB AT 12N117W.  

ABUNDANT TROPICAL MOISTURE E OF 112W ENJOY MORE FAVORABLE UPPER 
LEVEL ENVIRONMENT WITH LIGHTER E WINDS ALOFT...WARM SEA SURFACE 
TEMPERATURES AND MORE AGGRESSIVE LOW LEVEL CONVERGING ALONG 
MONSOON TROUGH.   

ELSEWHERE AT THE LOWER LEVELS...

HIGH PRES CENTER 1032 MB WELL N OF AREA WEAKENS AS IT MOVES SE 
BEHIND WEAK SURFACE TROUGH FROM 33N127W TO 28N132W.  THIS 
DIMINISHES PREVIOUS FRESH NE BREEZE OVER NW CORNER OF E PAC 
BASIN.  LINGERING 8-9 FT NE SWELLS SUBSIDE BY SUN.   

LOW PRES CENTER AT 10N99W IS UNDER FAVORABLE UPPER LEVEL 
ENVIRONMENT AND EXPECTED TO DEVELOP TROPICAL ORGANIZATION WITHIN 
THE NEXT 18-24 HRS.

FRESH SW MONSOON BREEZE S OF 10N GET ABSORBED IN WIND FIELD 
SURROUNDING LOW PRES CENTER AT 10N97W WITH BUILDING SEAS UP TO 
12 FT IN S SEMICIRCLE.  DYNAMIC MODELS BRING TROPICAL CYCLONE 
CONDITIONS IN W-NW DIRECTION OVER 24-48 HOURS WITH POSSIBLE 
FURTHER INTENSIFICATION BEYOND THAT PERIOD.
   
$$
WALLY BARNES