000
AXPZ20 KNHC 250952
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...ITCZ/MONSOON TROUGH...
THE AXIS OF THE MONSOON TROUGH EXTENDS FROM E PANAMA TO 08N79W 
TO 07N92W TO 09N103W WHERE LOW LEVEL WINDS INDICATE THE ITCZ 
AXIS BEGINS. THE ITCZ AXIS CONTINUES W ALONG 09N TO 110W THEN 
TURNS NW IN RESPONSE TO AN EMBEDDED N TO S ORIENTATED TROUGH 
WITHIN THE ITCZ ALONG 117W. THE ITCZ AXIS RESUMES AT 10N117W AND 
CONTINUES W SW TO BEYOND 07N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS OBSERVED TO THE N OF 02N E OF 80W ALONG THE 
COAST OF COLOMBIA AND OVER THE SOUTHERN GULF OF PANAMA. SIMILAR 
CONVECTION IS NOTED WITHIN 120 NM EITHER SIDE OF A LINE FROM 
01N84W TO 05N88W TO 07N110W...AND WITHIN THE AREA BOUNDED BY 06N 
TO 14N BETWEEN 100W AND 125W.

...DISCUSSION...
AN DEEP LAYERED TROUGH HAS NEARLY STALLED JUST NW OF THE AREA 
WITH AN EMBEDDED UPPER CYCLONE FORMING AT 33N145W. AN UPPER 
ANTICYCLONE IS OVER NE NEW MEXICO WITH A RIDGE SW TO 30N118W. 
ANOTHER UPPER ANTICYCLONE IS AT 25N128W WITH A RIDGE SW TO 
12N139W. AN INVERTED UPPER TROUGH EXTENDS FROM 16N117W TO 
29N117W AND SEPARATES THE TWO UPPER RIDGES. THIS TROUGH EXTENDS 
OVER THE REMNANT LOW OF TROPICAL CYCLONE DORA WHICH IS FILLING 
RAPIDLY NEAR 25N116W. UPPER LEVEL CYCLONES ARE OVER THE DEEP 
TROPICAL PACIFIC AT 04N128W AND AT 03N107W.

UPPER DIFFLUENCE ALONG THE SOUTHERN PERIPHERY OF THE RIDGES AND 
ALONG THE NORTHERN EXTENT OF TROPICAL CYCLONE SETS UP AN AREA OF 
UPPER DIFFLUENCE WHICH IS ENHANCING THE CONVECTION ALONG THE 
ITCZ BETWEEN 100W AND 140W. THE DEBRIS MOISTURE IS FANNING OUT 
OVER THE AREA FROM 04N TO 13N BETWEEN 100W AND 120W. SOME DEBRIS 
MOISTURE IS ALSO ADVECTED N ALONG 135W FROM 11N TO 20N WHERE IT 
SEEMS TO EVAPORATE. DEBRIS MOISTURE FROM DORA IS NOTED ALONG 
119W FROM 18N TO 30N. DEBRIS MOISTURE FROM FORMER CONVECTION 
OVER INTERIOR OLD MEXICO HAS SPREAD W ACROSS THE GULF OF 
CALIFORNIA AND ACROSS THE BAJA CALIFORNIA PENINSULA TO OVER THE 
E PACIFIC E OF A LINE EXTENDING FROM 32N118W TO 17N107W TO 
17N99W.
  
AN UPPER TROUGH CONTINUES TO EXTEND W ACROSS THE SOUTHERN GULF 
OF MEXICO TURNING SW OVER SE OLD MEXICO. A BROAD UPPER RIDGE 
EXTENDS W OVER THE TROPICAL PACIFIC E OF 90W ACCOMPANIED BY 
DENSE DEBRIS MOISTURE.

AT THE LOW LEVELS A RIDGE EXTENDS FROM 32N140W TO 18N115W...WITH 
ASSOCIATED TRADES MAXING AT 15 KT. CROSS EQUATORIAL SE SWELLS... 
RESULTING IN SEAS TO 8 FT...ARE PROPAGATING NW ACROSS THE WATERS 
SW OF A LINE FROM 12N140W TO THE EQUATOR AT 110W. SOUTHERLY 
SWELL IS DOMINATE ACROSS THE ENTIRE DISCUSSION AREA MIXING WITH 
SECONDARY NE SWELL OVER AREA N OF 10N W OF 115W. 

GAP WINDS...NE TRADES OVER THE W CARIBBEAN ARE EXPECTED TO 
CONTINUE TO SURGE THROUGH THE GULF OF PAPAGAYO AT 15-20 KT EARLY 
THIS MORNING...THEN DIMINISH TO 10-15 KT LATE TODAY. NORTHERLY 
WINDS ARE SURGING ACROSS THE GULF OF TEHUANTEPEC AT 20 TO 25 
KT...BUT ARE EXPECTED TO DIMINISH BELOW 20 KT LATE TONIGHT.

$$
NELSON