000
AXPZ20 KNHC 262150
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JUL 26 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 11N86W TO 09N95W TO 13N116W TO 
10N134W THEN AS ITCZ TO 08N140W.  SCATTERED MODERATE CONVECTION 
WITHIN 210 NM OF AXIS FROM 95W TO 105W.  ISOLATED MODERATE 
CONVECTION WITHIN 90 NM OF AXIS FROM 112W TO 116W AND FROM 127W 
TO 135W.

...DISCUSSION...
STATIONARY 1031 MB HIGH PRES WELL NW OF BASIN SQUEEZE GRADIENT 
WITH THERMAL TROUGH ALONG CALIFORNIA BACKBONE FORCING SHORT-LIVED
GALE FORCE WINDS N OF 31N E OF 132W WED.  UPPER LEVEL CYCLONE 
RETROGRADES W FORCING HIGH PRES TO EASE GRADIENT AND ALLOW WINDS 
TO DIMINISH THU BUT ATTENDANT 8-9 FT SWELLS SPREAD S INTO E PAC
N OF 27N W OF 122W.

ELSEWHERE AT THE UPPER LEVELS...BROAD ANTICYCLONE AT 24N135W 
SUPPORT SURFACE RIDGE AND PRODUCE DRY SUBSIDING AIR MASS N OF 
15N W OF 128W.  CYCLONIC VORTEX AT 21N127W DRIFTS W DISPLACING 
RIDGE ALLOWING MOISTURE TO EXPAND W ALONG MONSOON TROUGH AND 
ITCZ.  

AT THE SURFACE...
TRADE WINDS EASE AS RIDGE MOVES W WITH LIGHT TO MODERATE 
NORTHEASTERLIES COVERING PORTION OF BASIN N OF MONSOON 
TROUGH/ITCZ W OF 120W.  MODERATE S-SW BREEZE DEVELOPS THU E OF 
100W AS MONSOON TROUGH STRENGTHENS WITH APPROACH OF TROPICAL 
WAVE TO CENTRAL AMERICA AND FAVORABLE UPPER LEVEL ENVIRONMENT 
ENHANCES CONVECTION E OF 90W.

CROSS-EQUATORIAL S SWELLS WITH SEAS TO 10 FT PROPAGATING N INTO 
E PAC S OF 10N E OF 130W DIMINISHING IN COVERAGE BY THU.
 
$$
WALLY BARNES