000
AXPZ20 KNHC 232141
TWDEP 

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE AUG 23 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 18O0 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH INLAND OVER CENTRAL AMERICA THEN OVER WATERS FROM 
18N103W TO 1008 MB LOW PRES NEAR 19N107W TO 11N120W RESUMES FROM 
14N132W TO 08N140W. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION FROM 11N TO 20N BETWEEN 102W AND 110W...AND FROM 13N 
TO 16N BETWEEN 110W AND 114W. SIMILAR CONVECTION IS NOTED NEAR 
11N116W. SCATTERED MODERATE WITHIN 90 NM EITHER SIDE OF MONSOON 
TROUGH W OF 134W. 

...DISCUSSION...

ALOFT...NE TO E UPPER LEVEL WINDS DOMINATE THE EPAC E OF 110W.
AN ANTICYCLONIC CIRCULATION IS NOTED W OF BAJA CALIFORNIA NEAR 
24N115W. UPPER DIFFLUENCE SOUTH OF THIS SYSTEM IS HELPING TO 
INDUCE CONVECTION FROM JUST WEST OF PUERTO VALLARTA MEXICO 
SOUTHWARD FOR SEVERAL HUNDRED MILES. ANOTHER ANTICYCLONE IS JUST 
W OF AREA NEAR 20N143W. IN BETWEEN...THERE IS AN UPPER LEVEL 
TROUGH EXTENDING FROM A CUT-OFF LOW NEAR 32N130W TO A COL NEAR 
15N128W.

HIGH PRES LOCATED N OF THE FORECAST AREA NEAR 33N136W EXTENDS A 
RIDGE OVER THE NW CORNER OF THE REGION. REMNANT LOW OF GREG IS 
STILL NOTED ON VISIBLE SATELLITE IMAGERY NEAR 19N129W. PRES 
GRADIENT NW OF THE LOW IS SUPPORTING 20 KT NE WINDS AND SEAS TO 
8 FT WITHIN 120 NM NW SEMICIRCLE. EXPECT THE LOW TO WEAKEN INTO 
A TROUGH AND DISSIPATE BY LATE WED.

ANOTHER WEAK LOW EMBEDDED IN THE MONSOON TROUGH IS EVIDENT NEAR 
19N107W. THIS LOW IS ENHANCING SW WINDS S AND SE OF THE TROUGH 
AND BUILDING SEAS TO 8-10 FT IN AN AREA FROM 08N TO 14N BETWEEN 
100W AND 110W AND FROM 05N TO 11N BETWEEN 110W AND 120W. 
ENVIRONMENTAL CONDITIONS ARE FORECAST TO BE LESS FAVORABLE FOR 
DEVELOPMENT ON WED AS THIS SYSTEM MOVES WESTWARD OVER COOLER 
WATERS. THE MONSOONAL FLOW IN THE 20 TO 25 KT RANGE IS FORECAST 
TO PERSIST AND EXPAND TO MOST OF THE AREA FROM 08N TO 15N 
BETWEEN 100W AND 120W...WITH SEAS BUILDING TO 10-11 FT BY THU.

PRES GRADIENT BETWEEN THE AFOREMENTIONED RIDGE AND LOW PRES OVER 
NW MEXICO IS RESULTING IN NW WINDS OF 15 TO 20 KT N OF 24N E TO 
118W TO THE W COAST OF BAJA CALIFORNIA. THE 1700 ASCAT PASS 
CONFIRMED THESE WIND SPEEDS. LITTLE CHANGE TO THIS PATTERN IS 
EXPECTED OVER THE NEXT 24 TO 48 HOURS. 

SE SWELLS WILL PROPAGATE ACROSS THE S WATERS MAINLY S OF 10N AND 
W OF 100W THROUGH THU BUILDING SEAS TO 8-9 FT.

$$
GR