000 AXPZ20 KNHC 092217 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED MAR 09 2016 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...INTERTROPICAL CONVERGENCE ZONE... A SURFACE TROUGH EXTENDS FROM 07N88W TO 01N107W. THE ITCZ AXIS EXTENDS FROM 01N110W TO00N124W TO BEYOND 02S140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 120 NM NW AND 30 NM SE OF TROUGH BETWEEN 88W AND 96W. SCATTERED STRONG CONVECTION NOTED FROM 03S TO 00.5N W OF 133W TO BEYOND 140W. ...DISCUSSION... AN UNUSUALLY STRONG MID TO UPPER TROUGH CONTINUES MOVING EASTWARD OVER WESTERN MEXICO AND THE SW U.S. THIS AFTERNOON. A VIGOROUS DEEP LAYERED CYCLONE EMBEDDED WITHIN THIS TROUGH HAS BEEN DIGGING SOUTHWARD WITHIN THE TROUGH...AND WAS CENTERED ALONG THE COAST OF NAYARIT AND EXTREME SOUTHERN SINALOA. A COLD FRONT ASSOCIATED WITH THIS SYSTEM HAS MOVED EASTWARD ACROSS THE SIERRA MADRES DURING THE PAST 36 HOURS AND WAS LOCATED FROM SOUTHERN TEXAS TO NORTHEASTERN MEXICO THIS AFTERNOON. HOWEVER... CONTINUED COLD NORTHERLY FLOW ALOFT INDUCED BY THE UPPER TROUGH HAS PRODUCED A SECONDARY COLD FRONT STRETCHED NORTH TO SOUTH ALONG THE SIERRA MADRE OCCIDENTALES OF NW MEXICO TO NEAR MANZANILLO THEN OVER WATER TO 14N110W TO 11N120W. THUNDERSTORMS PRODUCING SIGNIFICANT SNOW ACCUMULATIONS HAVE BEEN REPORTED TODAY ACROSS CENTRAL INTERIOR MEXICO NEAR THE COLD FRONT. THE MIDDLE TO UPPER TROUGH WILL SHIFT EASTWARD ACROSS MEXICO DURING THE NEXT FEW DAYS AND INTO THE W GULF OF MEXICO BY SAT...AND DRAG THE WEAKENING COLD FRONT EAST AND SOUTHEASTWARD TO NEAR PUERTO ANGEL ON THE PACIFIC COAST. OVER THE PACIFIC WATERS OFFSHORE OF MEXICO...STRONG NW WINDS BEHIND THE FRONT HAVE GRADUALLY DIMINISHED OVER THE PAST 24 HOURS...WITH WINDS 20-25 KT LINGERING NEAR THE FRONT E OF 110W...AND ON BOTH SIDES OF BAJA CALIFORNIA SUR. HOWEVER...A BROAD AREA OF HIGH SEAS IN LARGE NW SWELL CONTINUES TO PROPAGATE SOUTHEASTWARD ACROSS THE WATERS NW OF THE FRONT...WITH SEAS GENERALLY 10-15 FT NW OF THE FRONT...BETWEEN 125W AND BAJA CALIFORNIA. WINDS HAVE ALSO DIMINISHED INSIDE THE GULF OF CALIFORNIA...WHERE SEAS WERE 6 TO 9 FT FROM 24N TO NEAR LAS ISLAS TRES MARIAS. WINDS ARE EXPECTED TO INCREASE TO 20-25 KT AGAIN TONIGHT INSIDE THE GULF...MAINLY FROM 26N TO 30N...AND TO AROUND 20 KT ELSEWHERE...WITH SEAS BUILDING 5-8 FT TONIGHT S OF THE TIBURON BASIN. HIGH SEAS ACROSS THE OUTSIDE WATERS WILL CONTINUE TO SLOWLY SUBSIDE AS THE SWELL MOVES SOUTH AND SOUTHEASTWARD AND INTO THE TROPICS...SUBSIDING TO 8-12 FT BETWEEN 120W AND THE MEXICAN COASTLINE ALONG 100W N OF 10N BY THU AFTERNOON...AND TO 6-8 FT BY FRI AFTERNOON. VERY LARGE SURF AND DANGEROUS MARINE CONDITIONS WILL CONTINUE ALONG THE BAJA CALIFORNIA AND MEXICAN COASTLINE TONIGHT THROUGH THU MORNING. NW OF THE ABOVE...A 1023 MB HIGH PRESSURE CENTER IS LOCATED NEAR 30N125W AND EXTENDS A BROAD RIDGE SE TO NEAR 22N115W AND ALSO W- SW TO BEYOND 21N140W. THE PRESSURE GRADIENT TO THE S OF THE RIDGE IS SUFFICIENT TO CONTINUE TO PRODUCE FRESH NE TO E TRADE WINDS GENERALLY FROM 03N TO 21N W OF 115W. SEAS ARE GENERALLY 9 TO 11 FT ACROSS THIS AREA IN PREDOMINANTLY NW SWELL. THE HIGH WILL SHIFT SLOWLY E AND WEAKEN OVER THE NEXT 48 HOURS...REDUCING THE PRESSURE GRADIENT...THUS DECREASING THE WINDS TO MODERATE TO FRESH WITH SEAS SLOWLY SUBSIDING BELOW 8 FT. A NEW COLD FRONT MOVING OVER THE NW CORNER OF THE AREA THIS AFTERNOON WILL REACH FROM 30N135W TO 26N140W BY THIS EVENING. FRESH TO STRONG S TO SW WINDS ARE E OF THIS FRONT WITH SEAS BUILDING TO 8 TO 13 FT. THIS FRONT WILL MOVE EAST TO 30N130W TO 21N140W BY THU EVENING WHILE WEAKENING. MEANWHILE...A REINFORCING FRONT WILL MOVE ACROSS 30N140W THU AND WILL MERGE WITH THE WEAKENING COLD FRONT ON FRI. FRESH TO STRONG NW WINDS AND SWELL WILL BUILD SEAS TO 16 FT BEHIND THIS REINFORCING FRONT. $$ STRIPLING