000
AXPZ20 KNHC 280238
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.               

...SPECIAL FEATURE...

TROPICAL STORM MARTY IS CENTERED AT 15.3N 103.W...OR ABOUT 235  
MILES W-SW OF ACAPULCO MEXICO AND 190 MILES SSW OF ZIHUATANEJO 
MEXICO...AT 0300 UTC WITH AN ESTIMATED PRESSURE OF 994 MB.  
MAXIMUM SUSTAINED WINDS ARE 55 KT WITH GUSTS TO 65 KT. CURRENTLY 
NUMEROUS MODERATE TO STRONG CONVECTION IS OBSERVED WITHIN 120 NM 
OVER THE NE QUADRANT OF CENTER. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS NOTED ELSEWHERE WITHIN 120 NM OF LINE FROM 
17N99W TO 13N103W. MARTY IS DRIFTING N...OR 000 DEG AT 02 KT.  A 
MOVEMENT TOWARDS THE NE IS EXPECTED DURING MON NIGHT. THE STORM 
HAS LIKELY PEAKED IN INTENSITY AND WILL CONTINUE TO ENCOUNTER 
WESTERLY WIND SHEAR RESULTING IN A WEAKENING TREND BEGINNING ON 
MON NIGHT. HEAVY RAINFALL IS EXPECTED TO PRODUCE LIFE-
THREATENING FLASH FLOODS AND MUDSLIDES ACROSS THE SOUTHERN STATE 
OF GUERRERO MEXICO THROUGH THU. LARGE SWELLS WILL REACH THE 
PACIFIC COAST OF MEXICO BETWEEN 100-105W THROUGH THE MIDDLE OF 
THE WEEK RESULTING IN DANGEROUS SURF AND RIP CURRENTS. INTERESTS 
ARE ENCOURAGED TO REFER TO THE LATEST NHC FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR UPDATED 
DETAILS. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH IS ANALYZED BETWEEN 10-11N FROM THE CARIBBEAN 
COAST OF COLOMBIA AT 11N75W TO THE PACIFIC COAST OF COSTA RICA 
AT 10N85W THEN CONTINUES W TO 09N94W WHERE IT LOSES IDENTITY IN 
THE BROAD CYCLONIC CIRCULATION ASSOCIATED WITH TROPICAL STORM 
MARTY. SCATTEROMETER WINDS SUGGEST THAT THE MONSOON TROUGH 
RESUMES SW OF MARTY NEAR 14N108W...AND CONTINUES SW THROUGH AN 
EMBEDDED 1009 MB LOW PRESSURE AT 10N121W TO 08N127W...THEN TURNS 
NW TO 12N135W....THEN SW TO BEYOND 11N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS OBSERVED WELL S OF THE MONSOON 
TROUGH WITHIN 150 NM OF 06N90W...AND WITHIN 120 NM EITHER SIDE 
OF A LINE FROM 12N103W TO 10N119W TO 07N129W TO 12N137W. 

THE SURFACE LOW AT 10N121W WILL MOVE NE TO A POSITION NEAR 
11N118W LATE MON AND NEAR 12N116W LATE TUE. SOUTHERLY FLOW SE OF 
THE LOW IS AT 20-25 KT WITHIN 180 NM SE OF A LINE FROM 07N122W 
TO 10N110W WITH 7-10 FT SEAS. CROSS EQUATORIAL SOUTHERLY SWELL 
IS MIXING WITH LONG PERIOD NW SWELL...RESULTING IN COMBINED SEAS 
OF 7-9 FT...SURROUNDING THIS AREA OF STRONGER SOUTHERLY WINDS TO 
THE S OF 11N BETWEEN 90-127W. 
  
A SURFACE RIDGE EXTENDS SE FROM 32N130W TO 16N115W. A 1011 MB  
SURFACE LOW HAS OCCLUDED NEAR 31N136W AND IS TRAILING A WEAK 
COLD FRONT SW ACROSS THE DISCUSSION AREA FROM 30N132W TO 25N113W 
WHERE IT BECOMES STATIONARY TO 20N140W. THIS WEAK COLD FRONT 
WILL CONTINUE E TO A POSITION FROM 32N130W TO 25N134W TO 20N138W 
ON MON AS A SECOND COLD FRONT MOVES INTO THE DISCUSSION AREA 
FROM 32N135W TO 26N140W. NORTHERLY WINDS WILL INCREASE TO 20-25 
KT N OF 30N W OF THE  SECOND FRONT ON SUN...WITH NW-N 15-20 KT 
WINDS EXPECTED S OF 30N W OF THE FRONT. COMBINED SEAS WILL 
INCREASE TO 8-12 FT N OF 30N AND 7-10 FT S OF 30N PRIMARILY IN 
MIXED N AND S SWELL. THE FIRST FRONT WILL WEAKEN TO A FRONTAL 
TROUGH FROM 32N128W TO 20N140W ON TUE AS THE SECOND FRONT BEGINS 
TO WEAKEN FROM 30N134W TO 26N135W. BY THEN ASSOCIATED WINDS WILL 
HAVE DIMINISHED TO 15-20 KT AND SEAS SUBSIDED TO 5-7 FT.
    
$$
NELSON