000
AXPZ20 KNHC 170325
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI AUG 17 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 
0300 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION HECTOR AT 20.2N 116.0W AT 0300 UTC MOVING 
N-NW OR 340 DEG AT 04 KT WITH MAXIMUM WINDS 25 GUSTS TO 35 KT. 
CENTRAL PRESSURE 1005 MB.  HECTOR EXPECTED TO WEAKEN FURTHER TO 
A REMNANT LOW PRES LATE TONIGHT AS ONLY MODERATE CONVECTION IS 
NOTED AND NOW RESTRICTED TO JUST WITHIN 120 NM IN ITS WESTERN 
QUADRANT.  MODERATE WIND SHEAR ALOFT AND COOLER SST ARE TAKING A 
HEAVY TOLL ON THE SYSTEM.  SEE LATEST NHC FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 08N78W TO 11N92W TO EMBEDDED LOW PRES 08N99W 
1009 MB TO 07N105W THEN RESUMES FROM 15N119W TO BEYOND 09N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 240 NM S OF 
AXIS W OF 119W.   

...DISCUSSION...
UPPER LEVEL CYCLONE N OF AREA AT 38N132W HAS TROUGH EXTENDING S 
TO AN ILL-DEFINED CYCLONE AT 18N132W.  MODERATE TO STRONG 
SUBSIDING AIR MASS REMAINS DRY AND STABLE N OF MONSOON TROUGH W 
OF 121W.  FURTHER E...MID TO UPPER LEVEL ANTICYLONE CENTERED 
OVER NW MEXICO AT 28N109W FLOWS WARM MOIST TROPICAL AIR MASS 
INTO E PAC E OF 120W.  ABUNDANT MOISTURE ALOFT E OF MONSOON 
TROUGH AXIS PROVIDES ONE INGREDIENT FOR DEVELOPMENT OF 1009 MB 
LOW PRES CENTER AT 08N99W...BUT PRESENT STEADY FLOW OF MODERATE 
EASTERLY WIND SHEAR PREVENT ANY SIGNIFICANT INTENSIFICATION.  
MODEL GUIDANCE SOLUTIONS PLAY IT SHY ON STRENGTHENING SYSTEM BUT 
DO MAINTAIN SORT OF CIRCULATION AND LOWER PRESSURES IN REGION. 
FORECAST DOES NOT CONSIDER IT AN IMMEDIATE THREAT TO BECOME A 
TROPICAL FEATURE.
 
ELSEWHERE AT THE LOWER LEVELS...HIGH PRES CENTER 1016 MB AT 
30N127W PRESENTING AN OBSTACLE FOR HECTOR NW TRACK.  REMNANTS 
ARE EXPECTED TO DRIFT FURTHER N THEN NE BEFORE DISSIPATING 
WITHIN 48 HRS.  

CROSS EQUATORIAL LONG PERIOD S SWELL PROPAGATING N AS FAR AS 19N 
WITH SEAS TO 10 FT IS EXPECTED TO SUBSIDE FRI.

$$
WALLY BARNES