000
AXPZ20 KNHC 270316
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1205 UTC WED JUL 27 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 
0300 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 10N85W TO 09N88W TO 12N105W TO 
12N128W TO 10N134W THEN AS ITCZ TO 08N140W.  SCATTERED MODERATE 
CONVECTION WITHIN 180 NM S OF AXIS FROM 97W TO 104W.  ISOLATED 
MODERATE CONVECTION WITHIN 60 NM OF AXIS FROM 112W TO 117W AND 
FROM 128W TO 134W.

...DISCUSSION...
STATIONARY 1032 MB HIGH PRES WELL NW OF BASIN MAINTAINS TIGHT 
GRADIENT WITH THERMAL TROUGH ALONG CALIFORNIA COAST FORCING GALE 
FORCE WINDS N OF 31N FROM 121W TO 132W THROUGH THU.  UPPER LEVEL 
CYCLONE RETROGRADES W FORCING HIGH PRES TO EASE GRADIENT AND 
ALLOW WINDS TO DIMINISH LATE THU BUT ATTENDANT 8-10 FT SWELLS 
SPREAD S INTO E PAC N OF 27N W OF 123W.

ELSEWHERE AT THE UPPER LEVELS...BROAD ANTICYCLONE AT 25N135W 
SUPPORT SURFACE RIDGE AND PRODUCE DRY SUBSIDING AIR MASS N OF 
16N W OF 128W.  SHARP COMPLEX TROUGH WITH CYCLONIC VORTICES AT 
21N127W AND 25N123W DRIFTS W DISPLACING RIDGE AND 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 TO 22N W OF 120W.  MODERATE S-SW BREEZE DEVELOPS  
LATE 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 LATE THU.
 
$$
WALLY BARNES