000
AXPZ20 KNHC 280900
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC MON SEP 28 2015

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 
0830 UTC.               

...SPECIAL FEATURES...

TROPICAL STORM MARTY CENTERED NEAR 15.6N 103.0W AT 28/0900 UTC 
OR 148 NM SSW OF ZIHUATANEJO MEXICO AND 196 NM WSW OF ACAPULCO 
MEXICO MOVING N AT 2 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 
990 MB. MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 
KT. SCATTERED STRONG CONVECTION IS WITHIN 75 NM OF THE CENTER. 
NUMEROUS MODERATE CONVECTION IS ELSEWHERE WITHIN 150 NM OF THE 
CENTER...EXCEPT 240 NM IN THE SW QUADRANT. MARTY IS FORECAST TO 
MOVE SLOWLY TO THE N THIS MORNING...THEN NE LATER TODAY THROUGH 
TUE. DEEP TROPICAL MOISTURE WILL CONTINUE TO SPREAD NORTHWARD 
ACROSS SOUTHWESTERN MEXICO INCREASING THE LIKELIHOOD FOR 
LOCALIZED FLASH FLOODING AND MUDSLIDES. IN ADDITION...LARGE 
SWELLS WILL PROPAGATE TOWARD SHORE RESULTING IN DANGEROUS SURF 
AND AN INCREASED THREAT OF RIP CURRENTS. SEE LATEST NHC FORECAST 
/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR  
MORE DETAILS.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH AXIS EXTENDS FROM 14N106W TO 13N114W TO LOW 
PRES NEAR 09N122W TO 08N130W TO 12N140W. SCATTERED MODERATE 
CONVECTION IS WITHIN 150 NM S OF THE AXIS BETWEEN 106W AND 134W.

...DISCUSSION...

SWELLS GENERATED BY T.S. MARTY ARE FORECAST TO PROPAGATE WELL 
AWAY FROM THE SYSTEM OFF TO THE NW...OFFSHORE OF THE BAJA 
CALIFORNIA PENINSULA BY TUE AFTERNOON THROUGH LATE TUE NIGHT 
WITH SEAS OF 7-9 FT.

NEARLY STATIONARY LOW PRES OF 1009 MB IS NEAR 32N135W WITH A 
COLD FRONT EXTENDING FROM 30N131W TO 25N135W THEN CONTINUING AS 
A STATIONARY FRONT TO 21N140W. A RECENT ASCAT-B SCATTEROMETER 
PASS SHOWED MODERATE TO FRESH WINDS W OF THE FRONT ACROSS THE 
WATERS S OF 30N WITH STRONGER WINDS TO THE N. SEAS OF 8-11 FT 
ARE PROPAGATING INTO THE NW CORNER OF THE DISCUSSION WATERS. THE 
INITIAL COLD FRONT WILL DRIFT TO THE E WHILE DECAYING DURING THE 
NEXT 24 HOURS WITH A NEW REINFORCING FRONT ARRIVING BY 24 HOURS. 
THE SECOND FRONT WILL THEN ALSO WEAKEN BY 48 HOURS WITH 
CONDITIONS GRADUALLY IMPROVING.

A 1008 MB SURFACE LOW NEAR 10N122W WILL MOVE TO A POSITION NEAR 
11N118W BY 24 HOURS AND THEN TO 12N116W BY 48 HOURS. 
SCATTEROMETER DATA INDICATED FRESH TO STRONG WINDS SE OF THE LOW 
CONTINUING EASTWARD TOWARD T.S. MARTY S OF THE MONSOON TROUGH. 
MEANWHILE CROSS EQUATORIAL SOUTHERLY SWELL IS MIXING WITH LONG 
PERIOD NW SWELL RESULTING IN COMBINED SEAS OF 8-11 FT 
SURROUNDING THE AREA OF WINDS...AND ACROSS THE REMAINDER OF   
THE S CENTRAL WATERS. THESE CONDITIONS ARE FORECAST TO PERSIST 
DURING THE NEXT 24-48 HOURS.
    
$$
LEWITSKY