000
AXPZ20 KNHC 150355
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED AUG 15 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.

...SPECIAL FEATURE...
TROPICAL STORM HECTOR CENTERED AT 17.3N 115.1W AT 15/0300 UTC 
MOVING W OR 260 DEG AT 3 KT.  ESTIMATED MINIMUM CENTRAL PRES 999 
MB. MAXIMUM SUSTAINED WIND SPEED 35 WITH GUSTS TO 45 KT. HECTOR 
SIGNIFICANTLY WEAKENED BY MODERATE WIND SHEAR ALOFT AND COOLER 
SST.  ITS CENTER HAS BECOME EXPOSED AND SCATTERED MODERATE 
CONVECTION...PREVIOUSLY RESTRICTED TO SW QUADRANT...HAS BLOSOMED 
AND EXPANDED INTO S QUADRANT.  APPEARANCE STILL SHOW A DOWNWARD 
TREND.  HECTOR EXPECTED TO BECOME TROPICAL DEPRESSION LATE WED.  
MODELS AGREE ON SCENARIO AS OVERALL ENVIRONMENT REMAINS 
ADVERSE.  SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/ WMO 
HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS.

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

MONSOON TROUGH EXTENDS FROM 13N88W TO EMBEDDED 1008 MB LOW PRES 
AT 09N93W TO 09N98W THEN RESUMES FROM 13N117W TO 09N138W.  ITCZ 
AXIS HENCE TO BEYOND 09N140W.  ISOLATED MODERATE CONVECTION N OF 
05N E OF 97W.  SCATTERED MODERATE CONVECTION WITHIN 90 NM S OF 
AXIS FROM 117W TO 127W.

...DISCUSSION...
ILL-DEFINED UPPER LEVEL CYCLONE AT 27N119W HAS ASSOCIATED TROUGH 
EXTEND S-SW TO 20N123W...JUST W OF TROPICAL STORM HECTOR...AND 
ONE OF THE CONTRIBUTORS TO HECTORS WEAKENING.  BROAD UPPER LEVEL 
ANTICYLONE CENTER JUST W OF FORECAST REGION AT 22N142W HAS RIDGE 
EXTENDING NE TO 32N122W.  DRY STABLE AIR MASS COVER LARGE REGION 
OF BASIN MAINLY N OF 15N W OF 118W.  AFOREMENTIONED CYCLONE 
EXTEND DRY SLOT FURTHER E TO BAJA CALIFORNIA COAST.  SECOND 
ANTICYCLONE OVER CENTRAL MEXICO MAINTAINS FLOW OF MOIST TROPICAL 
AIR MASS INTO E PAC E OF 115W.  

...AT THE LOWER LEVELS...
LOW PRES CENTER 1008 MB AT 09N93W EMBEDDED IN MONSOON TROUGH 
REMAINS UNDER MODERATE NE SHEAR ALOFT AND AT THE EDGE OF REGION 
OF A DRY AIR POCKET.  STRONG MONSOONAL SW WINDS JUST NW OF LOW 
PRES DO NOT HELP ORGANIZED TROPICAL CIRCULATION.  SO CONDITIONS 
ARE MIXED AND NONE OF THE MODEL GUIDANCE SOLUTIONS GIVES MUCH 
ATTENTION TO SYSTEM.  FORECAST KEEPS LOW IN MAP WITH VERY LOW 
PROBABILITY OF DEVELOPMENT. 

CROSS EQUATORIAL SOUTHERLY SWELL RESULTING IN 10-11 FT SEAS 
PROPAGATING N ACROSS E PAC WATERS S OF 10N E OF 120W.  

$$
WALLY BARNES