000 AXPZ20 KNHC 010851 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU OCT 01 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... DOWNGRADED POST-TROPICAL REMNANT LOW MARTY CENTERED NEAR 16.7N 104.4W AT 01/0900 UTC OR 139 NM S OF MANZANILLO MEXICO MOVING WNW AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. SCATTERED MODERATE CONVECTION IS BETWEEN 15 NM AND 75 NM IN THE N QUADRANT OF MARTY. EVEN THOUGH MARTY IS NO LONGER A TROPICAL CYCLONE ADDITIONAL MOISTURE WILL CONTINUE TO SPREAD NORTHEASTWARD ACROSS SW MEXICO WHICH COULD RESULT IN ADDITIONAL HEAVY RAINS AND LOCALIZED FLASH FLOODING. SWELLS ASSOCIATED WITH MARTY WILL GRADUALLY SUBSIDE AS THE REMNANT LOW SPINS DOWN... DISSIPATING INTO A TROUGH BY 36 HOURS. SEE THE FINAL NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. A 1007 MB LOW IS EMBEDDED IN THE MONSOON TROUGH NEAR 10.5N121W. SCATTERED MODERATE CONVECTION IS WITHIN 240 NM IN THE SE QUADRANT OF THE LOW. FRESH TO STRONG S-SW WINDS ARE OCCURRING WITHIN 180 NM SE OF A LINE FROM 15N119W TO 09N123W WHILE A LARGE AREA OF CROSS-EQUATORIAL SOUTHERLY SWELL WITH SEAS OF 8-10 FT SURROUNDS THE LOW ACROSS THE S CENTRAL WATERS. THE LOW IS FORECAST TO MOVE TO NEAR 12N123.5W BY 24 HOURS...THEN TO NEAR 11.5N128W BY 48 HOURS AND ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BECOME MORE FAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT THROUGH 48 HOURS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 09N82W TO 09N95W TO 13N104W THEN RESUMES FROM 17N106W TO LOW PRES NEAR 10.5N121W 1007 MB TO 07N133W TO 09N140W. NO ITCZ AXIS IS PRESENT. SCATTERED MODERATE CONVECTION IS FROM 07N TO 09N BETWEEN 83W AND 86W...FROM 06N TO 08N BETWEEN 88W AND 90W...WITHIN 150 NM N OF THE AXIS BETWEEN 116W AND 119W...FROM 07N TO 11N BETWEEN 122W AND 130W...AND ALSO FROM 12N TO 15N BETWEEN 123W AND 130W. ...DISCUSSION... A SURFACE RIDGE EXTENDS ACROSS THE AREA FROM 1018 MB HIGH PRES NEAR 32N139W THROUGH 28N133W TO 22N119W. THE RIDGING IS BEING COMPROMISED BY A WEAKENING COLD FRONT WHICH IS ANALYZED FROM 1011 MB LOW PRES N OF THE AREA NEAR 37N129W THROUGH 32N125W TO 25N134W THEN CONTINUES AS A STATIONARY FRONT TO 22N140W. THE FRONT WILL BECOME DIFFUSE DURING THE NEXT 24 HOURS WHICH WILL ALLOW RIDGING TO BUILD BEHIND IT OVER NORTHERN WATERS. THE PRES GRADIENT WILL TIGHTEN AS THIS OCCURS...ESPECIALLY ALONG THE BAJA CALIFORNIA PENINSULA WITH FRESH N-NW WINDS EXPECTED LATE TONIGHT THROUGH FRI OFF THE PACIFIC COAST OF BAJA CALIFORNIA NORTE. AS A RESULT...SEAS WILL BUILD TO 8 FT N OF 28N BETWEEN 115W AND 118W MEANWHILE TROUGHING WILL BUILD JUST W OF THE AREA DIRECTING FRESH SE TO S WINDS OVER THE NW WATERS FRI. SEAS ARE EXPECTED TO BUILD TO 8 TO 10 FT HERE BY EARLY FRI IN MIXED SE AND NW SWELL BUILDING UP TO 12 FT NEAR 30N140W BY LATE FRI NIGHT AS THE EDGE OF SEAS OF 8 FT OR GREATER SPREADS TO THE SE COVERING THE WATERS N OF 22N W OF 130W BY LATE FRI NIGHT. GAP WINDS... GULF OF TEHUANTEPEC...HIGH PRES IS BUILDING OVER THE WESTERN GULF OF MEXICO AND THE EASTERN COASTAL SECTIONS OF MEXICO. AS A RESULT...A SURGE OF STRONG TO NEAR GALE FORCE N-NE WINDS IS OCCURRING FROM THE GULF DOWNSTREAM TO 14.5N95.5W AS CONFIRMED BY RECENT ASCAT AND ASCAT-B SCATTEROMETER PASSES. THESE CONDITIONS WILL CONTINUE THROUGH THE END OF THE WEEK...AND MODEL GUIDANCE WILL NEED TO BE MONITORED IN CASE A GALE WARNING IS REQUIRED. THE LATEST TAFB-NWPS WAVE MODEL OUTPUT INDICATES SEAS BUILDING TO 12 FT BY LATE TONIGHT INTO FRI MORNING. $$ LEWITSKY