000
AXPZ20 KNHC 141534
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE AUG 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1445 UTC.

...SPECIAL FEATURE...

TROPICAL STORM HECTOR CENTERED NEAR 18.1N 114.4W AT 14/1500 UTC 
MOVING W OR 280 DEG AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 
IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 
50 KT. HECTOR CONTINUES TO EXPERIENCE MODERATE EASTERLY SHEAR 
WITH NUMEROUS STRONG CONVECTION OBSERVED WITHIN 210 NM OVER THE 
SW SEMICIRCLE. SCATTERED MODERATE CONVECTION IS ALSO NOTED IN A 
SMALL BAND NE OF THE CENTER WITHIN 30 NM EITHER SIDE OF A LINE 
FROM 18N110W TO 19N113W. HECTOR IS FORECAST TO REMAIN AS A 
MINIMAL TROPICAL STORM DURING THE NEXT 24-36 HOURS THEN IS 
EXPECTED TO WEAKEN TO A DEPRESSION THU MORNING AND TO A REMNANT 
LOW FRI MORNING AS THE SYSTEM MOVES ACROSS A GRADUAL COOLING OF 
SURFACE WATERS AND UNDER A PERSISTENT SHEAR ENVIRONMENT. SEE 
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/ 
WTPZ23 KNHC FOR MORE DETAILS.

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

MONSOON TROUGH EXTENDS FROM 10N84W TO EMBEDDED LOW PRES AT 
09N91W TO 16N106W THEN CONTINUES W OF HECTOR FROM 14N120W TO 
11N128W. ITCZ AXIS IS FROM 11N128W TO 08N140W. SCATTERED 
MODERATE CONVECTION IS NOTED N OF 07N E OF 80W INCLUDING THE 
GULF OF PANAMA. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION 
CAN BE FOUND FROM 05N TO 10N BETWEEN 82W AND 90W. SIMILAR 
CONVECTION IS ALSO FROM 11N TO 16N BETWEEN 102W AND 106W. 
SCATTERED MODERATE IS WITHIN 60 NM S OF ITCZ AXIS W OF 137W.  

...DISCUSSION...

ALOFT...AN UPPER CYCLONE IS NOTED JUST N OF THE AREA AT 36N132W 
WITH AN UPPER TROUGH EXTENDING SW INTO THE NW CORNER OF THE 
DISCUSSION TO AROUND 28N132W. AN UPPER ANTICYLONE IS CENTERED 
JUST W OF THE FORECAST REGION AT 23N141W WITH A RIDGE EXTENDING 
E THEN NE TO NEAR 32N122W. ANOTHER ANTICYLONE IS NOTED OVER 
CENTRAL MEXICO NEAR 21N99W. A WEAK UPPER LEVEL LOW IS NEAR 
27N119W WITH A TROUGH STRETCHING MAINLY TO THE EAST ALONG 
26N113W TO 28N105W. NE UPPER LEVEL FLOW DOMINATES MOST OF THE 
FORECAST WATERS E OF 110W.  

A SURFACE LOW ANALYZED NEAR 16N103W HAS BEEN TRACKING NW 
PARALLEL TO THE PACIFIC COAST OF MEXICO WITH INTERMITTENT 
BANDING CONVECTION. LATEST SATELLITE IMAGERY SHOWS A BAND OF OF 
MODERATE TO ISOLATED STRONG CONVECTION EXTENDING FROM 11N TO 16N 
BETWEEN 102W AND 106W. MODEL GUIDANCE SUGGESTS THE LOW PRES WILL 
MOVE NW AND PARALLEL TO THE MEXICAN COAST OVER THE NEXT COUPLE 
OF DAYS REACHING A POSITION NEAR 20N118W BY THU MORNING. A SMALL 
AREA OF 20 TO 25 KT WINDS AROUND THE NE PERIPHERY OF THE LOW 
WILL BE ASSOCIATED WITH THIS SYSTEM. BEYOND THU MORNING...THE 
LOW PRES IS FORECAST TO BE ABSORBED BY THE LARGE CYCLONIC 
CIRCULATION OF HECTOR. 

A 1009 MB LOW PRES IS EMBEDDED IN THE MONSOON TROUGH NEAR 
09N91W. THE MOST RECENT ASCAT PASS AND FEW SHIP OBSERVATIONS 
SHOWED THE CYCLONIC CIRCULATION RELATED TO THIS SYSTEM WITH 
WINDS IN THE 10-15 KT RANGE. THIS WEAK LOW PRES WILL MOVE MAINLY 
WWD ALONG THE MONSOON TROUGH. NO TROPICAL CYCLONE DEVELOPMENT IS 
EXPECTED.

THE ENVELOPE OF CYCLONIC 20 KT OR GREATER WINDS ASSOCIATED WITH 
TROPICAL STORM HECTOR IS EXPECTED TO CHANGE LITTLE THE REST OF 
TODAY AND TONIGHT...THEN BEGIN TO SHRINK IN AREAL COVERAGE WED 
AND THU. SOUTHERLY MONSOON FLOW AT 20 TO 25 KT TO THE S OF 
HECTOR IS EXPECTED CONTINUE WITH SOUTHERLY SWELLS EXPANDING 
ACROSS THE AREA FROM 09N TO 23N BETWEEN 102W AND 118W DURING THE 
NEXT COUPLE OF DAYS. SOUTHERLY SWELL...RESULTING IN COMBINED 
SEAS OF 8 TO 10 FT... WILL PROPAGATE NE ACROSS THE PACIFIC 
WATERS S OF 09N BETWEEN 80W AND 105W INTERRUPTED BETWEEN 88W AND 
92W BY THE GALAPAGOS ISLANDS.  

$$
GR