000
AXPZ20 KNHC 180954
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN AUG 18 2013

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 
0900 UTC.
                                    
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...        
MONSOON TROUGH EXTENDS FROM 10N86W TO 1009 MB LOW PRES AT
11N109W TO 13N116W TO 1011 MB LOW PRES AT 13N128W...THEN ITCZ TO
BEYOND 11N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION 
WITHIN 120 NM N OF AXIS W OF 118W.  SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 90 NM W OF LOW PRES AT 11N109W. 

...DISCUSSION...                                                 
BROAD UPPER LEVEL ANTICYCLONE AT 22N131W DRIFT W AND MAINTAINS
A DRY SUBSIDING AIR MASS OVER NW QUARTER OF BASIN N OF 15N W OF
118W.  WEAKENING INVERTED TROUGH FROM 32N121W TO 18N116W KEEPS
ADVECTED MOISTURE ON ITS E SIDE OVER BAJA CALIFORNIA.  TROUGH 
EXPECTED TO DISSIPATE WITHIN NEXT 48 HOURS.  ABUNDANT TROPICAL
MOISTURE CONTINUE TO FLOW ALONG MONSOON TROUGH AND ITCZ AND SST
REMAIN HIGH.  ONLY UPPER LEVEL ENVIRONMENT REMAINS UNFAVORABLE
FOR TROPICAL DEVELOPMENT AT THIS TIME. WITH DISSIPATING TROUGH
...THIS IS LIKELY TO CHANGE SOON.

...ELSEWHERE AT THE LOWER LEVELS...
SURFACE HIGH PRES CENTER NW OF AREA AT 36N142W EXTENDS BROAD
RIDGE SE TO 20N118W.  GENTLE TO MODERATE NE TRADES WITH SEAS
BELOW 8 FT REMAINS COMMON ACROSS WESTERN PORTION OF BASIN.  

SCATTERED MODERATE TO STRONG CONVECTION WITHIN 90 NM WESTERN 
SEMICIRCLE OF LOW PRES AT 11N109W MAY INCREASE AS UPPER LEVEL
TROUGH DISSIPATES AFTER 48 HOURS AND LOW PRES IS ALLOWED TO
INTENSIFY.  MODEL GUIDANCE SHOWS INCREASING WINDS ON E SIDE
WITH SEAS REACHING 8-9 FT LATE IN THE WEEK...AND GRADUAL 
INTENSIFICATION.  
 
$$ 
WALLY BARNES