000
AXPZ20 KNHC 170930
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0745 UTC.

...SPECIAL FEATURE...

POST-TROPICAL CYCLONE HECTOR WAS NEAR 20.8N 116.4W AT 0900 UTC 
MOVING N-NW OR 335 DEG AT 06 KT. MAXIMUM SUSTAINED WINDS WERE 25 
GUSTS TO 35 KT WITHIN 150 NM SE QUADRANT ACCORDING TO THE 0528 
UTC ASCAT PASS. THE CENTRAL PRESSURE WAS 1005 MB. HECTOR WAS 
DEVOID OF SIGNIFICANT DEEP CONVECTION. MODERATE WIND SHEAR AND 
COOLER SEA SURFACE TEMPERATURES HAVE TAKEN THEIR TOLL ON THE 
SYSTEM. SEE THE FINAL NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS.

...TROPICAL WAVE...

A TROPICAL WAVE WAS ALONG 95W N OF 14N. SCATTERED MODERATE 
CONVECTION WAS WITHIN 150 NM E OF THE WAVE N OF 15N AS WELL AS 
OVER THE SOUTHERN MEXICO/GUATEMALA BORDER. THIS TROPICAL WAVE 
SHOULD FALL APART AS IT MOVES WESTWARD OVER THE HIGH TERRAIN OF 
SOUTHERN MEXICO TOMORROW. 


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

THE MONSOON TROUGH AXIS WAS ANALYZED FROM 08N78W TO 11N86W THEN 
CONTINUES FROM 11N93W TO 1009 MB LOW PRES NEAR 09N99W TO 10N105W 
THEN CONTINUES FROM 16N120W TO 13N130W TO 09N140W. NUMEROUS 
MODERATE TO STRONG CONVECTION WAS S OF THE AXIS TO 03N E OF 
80W. 

...DISCUSSION...

AN UPPER LEVEL CYCLONE IS N OF AREA AT 38N134W AND HAS A TROUGH 
EXTENDING S TO A COL NEAR 22N131W THEN THROUGH A WEAKER CYCLONE 
NEAR 16N125W TO 10N120W. A WEAK SURFACE REFLECTION OF THIS 
TROUGH LIES OVER FORECAST WATERS FROM 30N133W TO 32N132W. 
ANTICYCLONES NEAR 21N149W AND OVER NW MAINLAND MEXICO NEAR 
29N111W EXTEND A RIDGE BETWEEN THEM THROUGH THE AFOREMENTIONED 
COL. WATER VAPOR IMAGERY SHOWS STRONG SUBSIDENCE N OF 15N W OF 
127W. THE ANTICYCLONE OVER NW MAINLAND MEXICO IS PROPELLING MID 
TO UPPER LEVEL MOISTURE WEST OF 120W. DIFFLUENCE ASSOCIATED WITH 
THIS ANTICYCLONE IS ENHANCING CONVECTION OVER THE SOUTHERN GULF 
OF CALIFORNIA. 

WEAK 1009 MB LOW PRES LIES ALONG THE MONSOON TROUGH AT 09N99W. 
SATELLITE IMAGERY SHOWS THE LIMITED DEEP CONVECTION ASSOCIATED 
WITH THE LOW IS SKEWED WESTWARD BY EASTERLY SHEAR. THIS SHEAR IS 
EXPECTED TO INTENSIFY OVER THE NEXT FEW DAYS. THIS SYSTEM IS NOT 
EXPECTED TO DEVELOP FURTHER. 
 
1016 MB HIGH PRES CENTERED NEAR 29N128W IS PRESENTING AN 
OBSTACLE FOR THE NW MOTION OF THE REMAINS OF HECTOR. THE HIGH IS 
EXPECTED TO LINGER NEAR 30N130W THE NEXT FEW DAYS. THE REMNANTS 
ARE EXPECTED TO DRIFT FURTHER N BEFORE DISSIPATING ON SUN. 

CROSS EQUATORIAL LONG PERIOD S SWELL HAS PROPAGATED ALONG THE 
ENTIRE PACIFIC COASTLINE WITHIN THE FORECAST AREA. THE PERIOD OF 
THIS SWELL REMAINS AROUND 16-18 SECONDS. SEAS TO 10 FT CAN 
CURRENTLY BE FOUND NEAR THE REMAINS OF HECTOR. SEAS WILL 
GRADUALLY SUBSIDE THROUGH TODAY.

$$
SCHAUER