000
AXPZ20 KNHC 250400
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT AUG 25 2012

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 
0345 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

A MONSOON TROUGH EXTENDS FROM 08N78W TO 12N90W TO AN EMBEDDED 
SURFACE LOW PRESSURE 1010 MB AT 11N96W...WITH THE MONSOON TROUGH 
CONTINUING NW TO 15N105W...THEN SW TO 10N117W...THEN W TO BEYOND 
11N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
FROM 10N TO 13N BETWEEN 96W AND 101W...FROM 07N TO 10N BETWEEN 
101W AND 108W...FROM 06N TO 11N BETWEEN 113W AND 123W AND WITHIN 
90 NM EITHER SIDE OF A LINE FROM 10N123W TO 13N130W TO 11N138W. 

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS AT 23N140W WITH A RIDGE EXTENDING 
NE TO ANOTHER ANTICYCLONE AT 30N122W...WITH AN UPPER RIDGE 
EXTENDING E ACROSS THE NORTHERN BAJA CALIFORNIA PENINSULA TO A 
CREST OVER NORTHERN OLD MEXICO AT 25N98W. VERY DRY UPPER AIR IS 
ADVECTED NE ALONG THE PERIPHERY OF THE UPPER RIDGE TURNING SE 
ACROSS CALIFORNIA AND ARIZONA. CONVECTION IS ENHANCED S OF THE 
UPPER RIDGE ALONG THE PACIFIC COAST OF MEXICO WITH THE RESULTANT 
UPPER DEBRIS MOISTURE SPREADING W OVER THE SOUTHERN GULF OF 
CALIFORNIA AND OVER THE PACIFIC WATERS FROM 16N TO 23 BETWEEN 
THE WESTERN MEXICAN COAST AND 111W.    
    
AN UPPER CYCLONE IS OVER THE DEEP TROPICAL PACIFIC AT 16N135W 
AND IS ALSO ACCOMPANIED BY DRY UPPER AIR WITHIN 240 NM OF 
CENTER. 

AN UPPER TROUGH EXTENDS S ALONG THE EASTERN SEABOARD OF THE 
CONUS...ACROSS THE EASETRN GULF OF MEXICO AND THE WESTERN 
CARIBBEAN TO A BASE OVER COASTAL EL SALVADOR. STRONG 
NORTHEASTERLY UPPER FLOW IS OBSERVED OVER THE ENTIRE DEEP 
TROPICAL PORTION OF THE DISCUSSION AREA...BASICALLY TO S OF 
10N...AND IS ADVECTING DEBRIS MOISTURE...ASSOCIATED WITH 
CONVECTION ALONG THE MONSOON TROUGH...SOUTHWEST TO ALONG ABOUT 
04N WHERE IT EVAPORATES.        

ELSEWHERE AT THE LOW LEVELS...WEAK SURFACE LOWS ARE OBSERVED AT 
20N113W AND 16N115W BUT BOTH LACK SIGNFICANT CONVECTION. A BROAD 
RIDGE DOMIANTES THE SUBTROPICS W OF 120W WITH SURFACE WINDS 
GENERALLY 20 KT OR LESS. LONG PERIOD CROSS EQUATORIALLY SE 
SWELLS ARE OBSERVED IN THE WATERS S OF 04N W OF 135W. SOUTHERLY 
SWELLS ARE EXPECTED TO CROSS THE EQUATOR REACHING ALONG 08N 
BETWEEN 92W AND 118W OVER THE NEXT COUPLE OF DAYS.   

$$
NELSON