000 AXPZ20 KNHC 091446 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON FEB 09 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1300 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC...A NEW ROUND OF NORTHERLY FLOW WILL SEEP SOUTHWARD THROUGH THE WESTERN GULF OF MEXICO INTO CHIVELA PASS BY LATE TONIGHT. WINDS WILL RAPIDLY INCREASE IN THE GULF OF TEHUANTEPEC AND ARE EXPECTED TO BECOME GALE FORCE BY SUNRISE TUE AND DIMINISH BELOW GALE FORCE AROUND SUNSET TUE EVENING. WINDS ARE EXPECTED TO REMAIN JUST BELOW GALE FORCE FOR THE REMAINDER OF THE PERIOD ENDING WED MORNING. THE NORTHERLY FLOW IN THE WESTERN GULF OF MEXICO WILL PERSIST THROUGH TUE EVENING BEFORE STARTING TO WANE AND SHIFT MORE EASTERLY...BUT THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW SHOULD KEEP WINDS CLOSE TO 30 KT OVERNIGHT TUE NIGHT INTO WED MORNING. SEAS OF 8 FT OR GREATER WILL STRETCH DOWNSTREAM OF TEHUANTEPEC AS FAR S AS 10N...WITH MAXIMUM SEAS AROUND 13 FT DURING THE GALE WARNING PERIOD. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 10N84W TO LOW PRES NEAR 06N87W 1011 MB TO LOW PRES NEAR 05N95W 1011 MB TO 03N100W. THE ITCZ AXIS WAS ANALYZED FROM 03N100W TO 05N112W TO 04N130W TO 01N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 150 NM N OF THE AXIS BETWEEN 110W AND 116W. ...DISCUSSION... A 1022 MB SUBTROPICAL HIGH NEAR 28N132W EXTENDS A RIDGE AXIS SOUTHEASTWARD THROUGH 13N110W TO 12N100W AND ANOTHER SOUTHWESTWARD TO BEYOND 25N140W. MEANWHILE...AN UPPER TROUGH OFF THE BAJA CALIFORNIA PENINSULA IS REFLECTING LOWER PRESSURES AT THE SURFACE. THE PRESSURE GRADIENT BETWEEN THIS BROAD TROUGHING AND THE SOUTHEASTERN RIDGE AXIS IS GENERATING AN AREA OF 20-25 KT WINDS GENERALLY ALONG 117W-118W N OF 25N. THE SUBTROPICAL HIGH IS EXPECTED TO BE FORCED NORTH-NORTHEASTWARD BY A VAST...DEEP LAYERED TROUGH OVER THE N CENTRAL PACIFIC. THIS WILL SHIFT THE TIGHTEST PRESSURE GRADIENT AND AREA OF STRONGEST WINDS NORTHEASTWARD TO THE COAST OF BAJA CALIFORNIA NORTE. WINDS ARE EXPECTED TO DROP BELOW THE ADVISORY CRITERIA OF 20-25 KT THERE BY TUE AFTERNOON. AN UPPER LEVEL LOW LIES NEAR 08N121W AND REFLECTS A SURFACE TROUGH FROM 14N120W TO 04N122W. A BROAD UPPER JET LIES ON THE E SIDE OF THE UPPER LOW. ASCENT ASSOCIATED WITH THE LEFT FRONT QUADRANT OF THIS JET IS LIFTING TROPICAL MOISTURE AND ENHANCING CONVECTION N OF THE ITCZ BETWEEN 110W AND 116W AS WELL AS BETWEEN 60 NM AND 390 NM E OF THE TROUGH FROM 09N TO 13.5N. THE UPPER LOW IS FORECAST TO SHIFT NORTHEASTWARD AND PHASE WITH THE DEEP LAYERED TROUGH THAT IS SUPPORTING THE LOWER PRESSURES NEAR THE BAJA CALIFORNIA COAST. THE AFOREMENTIONED VAST...DEEP LAYERED TROUGH OVER THE N CENTRAL PACIFIC WILL GRADUALLY APPROACH THE NW WATERS ON TUE. SOUTHERLY WINDS WILL INCREASE TO A FRESH TO STRONG BREEZE IN NW WATERS TUE MORNING WITH SEAS BUILDING TO 8-12 FT HERE BY TUE AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE INTO THE AREA BY TUE NIGHT AHEAD OF THE COLD FRONT. SOUTHERLY WINDS AHEAD OF THE FRONT SHOULD INCREASE TO 30 KT AT THAT TIME. THE FRONT WILL PUSH INTO THE AREA BY WED MORNING...BUT THE MAIN MID-LEVEL IMPETUS FOR THE FRONT WILL MOVE NORTHWARD...ALLOWING WINDS TO DROP A NOTCH. SEAS WILL REACH AS HIGH AS 17 FT BEHIND THE FRONT. A SWATH OF NW SWELL WITH SEAS OVER 8 FT IS ALREADY IN PLACE W OF A LINE FROM THE COAST OF BAJA CALIFORNIA NEAR 29N TO 22N115W TO 05N130W TO 02N140W. SEAS AS HIGH AS 15 FT IN NW SWELL ASSOCIATED WITH A RECENTLY DISSIPATED COLD FRONT LIE IN THE AREA N OF 26N BETWEEN 124W AND 135W. SEAS OFFSHORE OF BAJA CALIFORNIA NORTE WILL REACH AS HIGH AS 12 FT OVERNIGHT TONIGHT AS THIS NW SWELL TRAIN APPROACHES THE COAST. THE LEADING EDGE OF THE AREA OF NW SWELL WITH SEAS OVER 8 FT WILL CONTINUE TO PROPAGATE SOUTHEASTWARD...SPREADING S ALONG THE COAST OF BAJA CALIFORNIA THROUGH WED MORNING. TO THE SW...TRADE WINDS WILL GRADUALLY WEAKEN FROM A FRESH BREEZE OVER W WATERS TO A MODERATE BREEZE AS THE SUBTROPICAL HIGH IS FORCED NORTHEASTWARD. GAP WINDS.... GULF OF PAPAGAYO...HIGH PRESSURE BUILDING OVER THE WESTERN GULF OF MEXICO TODAY WILL CONTINUE TO BUILD SOUTH THROUGH CENTRAL AMERICA ON TUE INTO WED. THIS WILL INCREASE THE PRESSURE GRADIENT ACROSS THE GULF OF PAPAGAYO BY THE END OF THE FORECAST PERIOD WED MORNING. FRESH TO STRONG E-NE WINDS ARE EXPECTED TO RETURN TO THE GULF OF PAPAGAYO BY WED MORNING WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW. $$ SCHAUER