000
AXPZ20 KNHC 091556
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 UTC FRI AUG 09 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.

...SPECIAL FEATURES...   
.LOW PRES CENTER 1008 MB AT 12N113 MOVES W AT 10 KT APPROACHES
REGION OF LIGHT SHEAR ALOFT WHILE CONTINUES OVER WARM SEA 
SURFACE TEMPERATURE.  ENVIRONMENT BECOMING MORE FAVORABLE AND
CONDUCIVE FOR STRENGTHENING.  NHC HAS LABELED A MEDIUM CHANCE TO
DEVELOP INTO TROPICAL CYCLONE OVER THE NEXT 48 HOURS AND HIGHER
WITHIN THE NEXT FIVE DAYS. 
                       
TROPICAL STORM HENRIETTE HAS MOVED W OF THE FORECAST AREA AND
CONTINUES TO WEAKEN.  WINDS AND SEAS OVER FORECAST AREA EXPECTED 
TO DIMINISH AND FALL BELOW THRESHOLD CRITERIA WITHIN THE NEXT
06 HOURS. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...   
MONSOON TROUGH EXTENDS FROM 10N86W TO 14N102W TO 1010 MB LOW
PRES AT 12N113W TO 11N118W TO 12N125W TO LOW PRES 1011 MB AT 
10N130W TO 07N137W THEN ITCZ TO BEYOND 06N140W.  SCATTERED
MODERATE ISOLATED STRONG CONVECTION WITHIN 180 NM OF AXIS W OF
114W.  SCATTERED MODERATE CONVECTION FROM 06N TO 10N E OF 100W. 

...DISCUSSION...
BROAD UPPER LEVEL RIDGE COVERS MOST OF REGION N OF 17N W OF 115W
WITH DRY SUBSIDING AIR MASS.  UPPER LEVEL CYCLONE 12N104W MOVES
W THROUGH SUN ADDING DIVERGENCE ALOFT AS IT APPROACHES EASTERN
SEMICIRCLE OF LOW PRES AT 12N113W.  ENHANCED CONVECTION MAY ADD
TO DIMINISHED SHEAR ALOFT AND WARMER OCEAN HEAT CONTENT.  THIS
TURN FOR A MORE FAVORABLE ENVIRONMENT AT BOTH UPPER AND LOWER
LEVELS MAY INTENSIFY SYSTEM THEREAFTER.     

WEAK LOW PRES CENTER AT 10N130W REMAINS UNDER MODERATE UPPER
LEVEL NE SHEAR BUT OVER STILL WARM SEA SURFACE TEMPERATURES AND
ABUNDANT TROPICAL MOISTURE.  SYSTEM HAS LOW POSSIBILITY OF 
TROPICAL DEVELOPMENT DURING NEXT 48 HOURS ALBEIT INCREASING WITH
TIME.  IT MAY CROSS W OF 140W BEFORE ABLE TO DEVELOP INTO A 
TROPICAL SYSTEM. 

...ELSEWHERE AT THE LOWER LEVELS...
STATIONARY HIGH PRES CENTER 1024 MB W OF AREA NEAR 31N148W HAS
RIDGE EXTEND SE TO 20N115W.  ABUNDANT TROPICAL MOISTURE REMAINS
ALONG ITCZ/MONSOON TROUGH WITH POTENTIAL OF STRONGER CONVECTION
NEAR BOTH LOW PRES CENTERS MENTIONED ABOVE. 

$$
WALLY BARNES