000 AXPZ20 KNHC 050234 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN OCT 04 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 0100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 08N77W TO 06N82W TO 11N97W TO LOW PRES NEAR 08N103W 1006 MB TO 06N111W...THEN CONTINUES FROM 18N117W TO LOW PRES NEAR 15N122W 1005 MB TO 10N129W TO 13N140W. SCATTERED MODERATE CONVECTION WAS N OF 05N E OF 80W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 120 NM N AND 240 NM S OF THE AXIS BETWEEN 98W-110W. SCATTERED MODERATE TO STRONG CONVECTION WAS FROM 07N-14N BETWEEN 121W-134W. ...DISCUSSION... A 1005 MB LOW IS EMBEDDED IN THE MONSOON TROUGH NEAR 15N122W. CONVECTION CONTINUES TO FLARE S OF THE LOW SINCE IT HAS MOVED INTO THE DIFFLUENT REGION OF THE UPPER JET...WITH SCATTERED MODERATE TO STRONG CONVECTION NOTED FROM 07N-14N BETWEEN 121W- 134W. THE SYSTEM IS BEING LURED TO THE NE BY AN AMPLIFYING UPPER TROUGH. THE 1804 UTC ASCAT-B PASS SHOWED A FRESH TO STRONG S-SW BREEZE WITHIN 240 NM SE SEMICIRCLE OF THE LOW. THE SYSTEM HAS WEAKENED A BIT SINCE THAT TIME AND IS FORECAST TO CONTINUE WEAKENING AS THE DIFFLUENT REGION OF THE UPPER JET PULLS NE AWAY FROM THE LOW LEVEL SYSTEM. THE LOW PRES SYSTEM IS EXPECTED TO OPEN TO A TROUGH MON NIGHT. HOWEVER...MERGING SW AND NW SWELL SHOULD HELP KEEP SEAS TO 8 FT THROUGH TUE EVENING. POST-TROPICAL REMNANT LOW MARTY HAS FINALLY MOVED ONSHORE NEAR MAZATLAN AT 24N107W. THE CENTRAL PRESSURE WAS ESTIMATED AT 1008 MB. SCATTERED MODERATE CONVECTION WAS FOUND FROM 17N TO 22.5N BETWEEN 104W AND 107W...INCLUDING INLAND OVER MAINLAND MEXICO. THE 1706 UTC ASCAT-A PASS HAD SHOWED S-SE WINDS TO 30 KT JUST OFF THE COAST FROM CABO CORRIENTES TO MAZATLAN. NOW THAT THE SYSTEM HAS MOVED INLAND...A FRESH TO STRONG BREEZE IS LIKELY LIMITED TO WATERS OFFSHORE N OF 23N E OF 107.5W AND SHOULD DIMINISH QUICKLY TONIGHT AS THE LOW DISSIPATES. SEAS ARE BELIEVED TO BE IN THE 8-10 FT RANGE IN THE MOUTH OF THE GULF OF CALIFORNIA AND SHOULD ALSO SUBSIDE RAPIDLY TONIGHT. A COLD FRONT HAS MOVED INTO THE FORECAST AREA FROM ENSENADA MEXICO TO 29N122W TO 32N131W. THE FRONT IS EXPECTED TO WEAKEN OVERNIGHT AND DISSIPATE ON MON. NW SWELL ASSOCIATED WITH THIS FRONT HAS BROUGHT SEAS IN THE 7-9 FT RANGE TO THE AREA N OF 27N BETWEEN 118W-131W. THIS AREA OF HIGHER SEAS WILL SUBSIDE BELOW 8 FT BY MON EVENING AS THE SWELL TRAIN TRAVELS SOUTHWARD. THE COLD FRONT HAS HELPED WEAKEN THE SURFACE RIDGING OVER N WATERS. AS A RESULT...ONLY MODERATE TO FRESH TRADE WINDS LIE N OF THE MONSOON TROUGH W OF 120W. A REGION OF GRADUALLY SUBSIDING SEAS...CURRENTLY IN THE 7-9 FT RANGE IN NW SWELL...LIES OVER W WATERS FROM 08N-18N. THESE SEAS WILL MERGE MON WITH AN AREA OF 8- 10 FT SEAS BEING GENERATED BY A LOW PRES SYSTEM W OF THE AREA MON AND TUE. GAP WINDS... GULF OF CALIFORNIA...AN AMPLIFIED UPPER TROUGH OVER THE WESTERN UNITED STATES AND NW MEXICO INDUCED A STRONG PRESSURE GRADIENT BETWEEN HIGH PRES IN THE U.S. GREAT BASIN AND LOW PRES IN THE SOUTHERN GULF OF CALIFORNIA WHERE THE REMNANTS OF MARTY HAVE JUST MOVED ONSHORE. THIS IS DRIVING STRONG TO NEAR GALE S-SW WINDS IN THE GULF OF CALIFORNIA N OF 30N WITH SEAS AS HIGH AS 8 FT. WINDS AND SEAS WILL DIMINISH HERE BY MON AFTERNOON. GULF OF TEHUANTEPEC...DEEP-LAYER RIDGING WILL BUILD OVER THE WESTERN GULF OF MEXICO AND NE MAINLAND MEXICO LATE MON INTO TUE. THIS WILL INCREASE THE PRESSURE GRADIENT ACROSS CENTRAL AMERICA. N WINDS ARE EXPECTED TO FUNNEL THROUGH CHIVELA PASS BEGINNING MON EVENING AND REACH NEAR GALE CONDITIONS IN THE GULF OF TEHUANTEPEC AROUND SUNRISE TUE WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW BEFORE BACKING OFF TO A FRESH TO STRONG BREEZE IN THE AFTERNOON...CONTINUING INTO TUE EVENING. $$ SCHAUER