000
AXPZ20 KNHC 252146
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON JUL 25 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 
2130 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH 08N78W TO 09N87W TO 11N105W. ITCZ AXIS 11N105W TO 
11N120W TO 09N130W TO BEYOND 08N140W. SCATTERED MODERATE TO 
STRONG N OF 03N E OF 80W AND WITHIN 90 NM OF THE MONSOON TROUGH 
BETWEEN 90W AND 100W. SCATTERED MODERATE ISOLATED STRONG 
ELSEWHERE WITHIN 150 NM OF THE MONSOON TROUGH BETWEEN 95W AND 
112W. SCATTERED MODERATE WITHIN 120 NM OF THE ITCZ BETWEEN 120W 
AND 130W...AND WITHIN 60 NM OF THE ITCZ W OF 130W. 

...DISCUSSION...
A MID/UPPER LEVEL RIDGE EXTENDS FROM ARIZONA/S CALIFORNIA WSW 
ACROSS BAJA CALIFORNIA INTO THE EPAC NEAR 30N120W. AN UPPER 
LEVEL ANTICYCLONE IS NOTED NEAR 23N131W WITH A RIDGE EXTENDING 
SW TO NEAR 13N140W. THE RIDGES WERE SEPARATED BY AN UPPER LEVEL 
INVERTED UPPER TROUGH WHICH EXTENDED FROM 17N125W TO 30N121W.
AN EMBEDDED MID LEVEL CYCLONE NEAR 28N121W REPRESENTS THE 
REMNANT MID LEVEL CIRCULATION OF FORMER TROPICAL CYCLONE DORA
WHICH IS NOW ANALYZED AS A SURFACE TROUGH ON THE 25/1800 UTC 
SURFACE MAP. THE TROUGH EXTENDS FROM 27N116W TO 23N114W. A 
1702 UTC ASCAT PASS CAPTURED THE TROUGH AXIS AND NOTED N TO NW 
WINDS OF 10 TO 15 KT ON THE WEST SIDE OF THE TROUGH. UPPER 
DIFFLUENCE ALONG THE SOUTHERN PERIPHERY OF THE RIDGES NOTED 
ABOVE IS ENHANCING THE CONVECTION ALONG THE ITCZ BETWEEN 100W 
AND 130W. A BROAD UPPER RIDGE EXTENDS W OVER THE TROPICAL 
PACIFIC E OF 90W AND IS HELPING TO INDUCE CONVECTION ALONG AND 
SOUTH OF THE MONSOON TROUGH. 

AT THE SURFACE A RIDGE EXTENDS FROM 32N140W TO 20N120W TO 
18N115W. SUBNORMAL TRADE WINDS ARE NOTED BETWEEN THE RIDGE AND 
THE ITCZ. 

CROSS EQUATORIAL SE SWELLS...RESULTING IN SEAS TO 8 FT...ARE 
PROPAGATING NW ACROSS THE WATERS SW OF A LINE FROM 10N140W TO 
THE EQUATOR AT 98W. THIS SWELL TRAIN WILL GRADUALLY DECAY 
THROUGH THE NEXT 24 HOURS AS A NEW SET OF CROSS EQUATORIAL SW 
SWELL MOVES NORTHWARD TO S OF 08N W OF 95W RAISING SEAS TO UP TO 
10 FT. 

GAP WINDS...NORTHERLY WINDS ARE SURGING THROUGH THE GULF OF 
TEHUANTEPEC AT 20 KT...BUT ARE EXPECTED TO DIMINISH BELOW 20 KT 
BY TUE MORNING. CURRENTLY...IXTEPEC IN THE STATE OF OAXACA 
MEXICO IS STILL REPORTING SUSTAINED WINDS OF 15 KT WITH GUSTS TO 
25 KT. NE TRADES CONTINUE TO SURGE THROUGH THE GULF OF PAPAGAYO 
AT 15-20. THESE WINDS ARE FORECAST TO DIMINISH TO 10-15 KT 
TONIGHT. 

LOOKING AHEAD...NWP MODEL GUIDANCE SUGGESTS A GRADUAL INCREASE 
IN THE SW MONSOONAL FLOW MAINLY S OF 07N BETWEEN 90W AND 105W. 
BEGINNING WED. EXPECT WINDS OF 20 TO 25 KT WITH BUILDING SEAS OF 
AROUND 10 FT.

$$
COBB