000
AXPZ20 KNHC 260243
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI AUG 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH FROM 13N87W TO 12N95W TO 19N105W TO 1004 MB LOW 
PRES NEAR 18N112W TO 12N120W TO 13N133W TO 10N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS FROM 12N TO 17N BETWEEN 
101W AND 106W...AND FROM 08N TO 12N BETWEEN 95W AND 98W. 
SCATTERED MODERATE WITHIN 60 NM OF LINE FROM 13N110W TO 11N115W. 

...DISCUSSION...
ALOFT...MODERATE UPPER-LEVEL NE TO E WINDS CONTINUE TO DOMINATE 
MOST OF FORECAST WATERS S OF 25N E OF 120W AND S OF AN 
ANTICYCLONIC CIRCULATION LOCATED OVER ARIZONA WHICH EXTENDS A 
RIDGE TO THE SW TO A COL NEAR 19N133W. A DIFFLUENT PATTERN ALOFT 
ASSOCIATED WITH THIS RIDGE IS HELPING TO INDUCE SOME CONVECTION 
S OF THE MONSOON TROUGH PARTICULARLY FROM FROM 12N TO 17N 
BETWEEN 101W AND 106W...AND FROM 08N TO 12N BETWEEN 95W AND 98W.
ANOTHER ANTICYCLONE IS LOCATED W OF THE AREA NEAR 18N143W. AN 
UPPER-LEVEL TROUGH ENTERS THE DISCUSSION AREA NEAR 30N132W THEN 
CONTINUES SW TO BEYOND 25N140W. THIS TROUGH IS ANCHORED TO A 
RATHER VIGOROUS CYCLONIC CIRCULATION LOCATED N OF AREA NEAR 
36N129W.

AT THE SURFACE...WEAK RIDGE REMAINS IN CONTROL OF THE WEATHER 
PATTERN ACROSS THE NW CORNER OF THE AREA. A LOW PRES TROUGH... 
WHAT IS LEFT OF REMNANT LOW GREG...EXTENDS FROM 20N134W TO 
14N135W. LIGHT TO MODERATE WINDS ARE EITHER SIDE OF THE TROUGH 
AXIS PER A MUCH EARLIER WINDSAT PASS. 

FRESH SW WINDS S OF THE MONSOON TROUGH DOMINATE A LARGE AREA 
GENERALLY WITHIN 240 NM EITHER SIDE OF A LINE FROM 08N122W TO 
14N105W. SIMILAR WINDS WERE ALSO NOTED FROM 05N TO 10N BETWEEN 
87W AND 100W. A 1624 ASCAT PASS WAS INSTRUMENTAL IN PROVIDING
ADDITIONAL DETAILS OF THESE WINDS. THE MONSOON TROUGH WILL 
REMAIN MODERATELY ACTIVE OVER THE NEXT COUPLE OF DAYS AS THE 
1004 MB LOW NEAR 18N112W CONTINUES TO MOVE WSW ALONG THE TROUGH. 
WAVE WATCH GUIDANCE CONTINUES TO BUILD SEAS TO 12 OR 13 FT BY 
SAT IN ASSOCIATION WITH THE FRESH TO STRONG MONSOONAL FLOW.

WINDS W OF BAJA CALIFORNIA HAVE DIMINISHED TO BELOW 20 KT. 
HOWEVER...A SWATH OF NW TO N WINDS OF 15 TO 20 KT IS NOTED PER 
THE 1800 ASCAT PASS BETWEEN THE AFOREMENTIONED RIDGE AND THE LOW 
PRES SYSTEM LOCATED NEAR 18N112W. THE LAST LOW LIGHT VISIBLE 
SATELLITE IMAGERY REVEALED A SWIRL OF LOW CLOUDS ASSOCIATED WITH 
THIS LOW WITH SCATTERED MODERATE CONVECTION JUST TO THE S OF THE 
CENTER. 

$$
COBB