000 AXPZ20 KNHC 100325 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN JAN 10 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...SPECIAL FEATURES... A COLD FRONT APPROACHING NW PORTIONS OF THE FORECAST AREA HAS REACHED 30N143W THIS EVENING. AS THE FRONT MOVES CLOSER TO THE AREA THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE NORTHERN WATERS AND THE FRONT WILL TIGHTEN...AND INCREASE SW WINDS TO GALE FORCE OVER THE NW WATERS N OF 27N AND E OF THE FRONT OVERNIGHT. THE GALE FORCE WINDS WILL THEN SHIFT N OF THE AREA SUN AFTERNOON AS LOW PRESSURE RESPONSIBLE FOR THE COLD FRONT LIFTS NE AND FURTHER AWAY FROM THE AREA. WITH THIS LOW MOVING FURTHER FROM THE AREA...THE PRESSURE GRADIENT OVER THE FORECAST WATERS WILL RAPIDLY WEAKEN AND DIMINISH WINDS TO 20 KT OR LESS OVER THE FORECAST WATERS BY EARLY MON MORNING. BEHIND THIS FRONT A FRESH PULSE OF LONG PERIOD...18-21 SECONDS...NW SWELL WILL MOVE SE INTO THE AREA. COMBINED SEAS ASSOCIATED TO THIS SWELL WILL PEAK NEAR 20-22 FT OVER THE FAR NW WATERS SUN NIGHT BEFORE STARTING TO SUBSIDE. GULF OF TEHUANTEPEC...A COLD FRONT IS MOVING THROUGH THE CENTRAL GULF OF MEXICO TONIGHT AND WILL MOVE ACROSS THE BAY OF CAMPECHE OVERNIGHT. COOL DENSE AIR BEHIND THIS FRONT WILL START TO FUNNEL THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC LATE TONIGHT WITH WINDS RAMPING UP TO GALE FORCE BY SUN MORNING AND CONTINUE THROUGH SUNDAY. WINDS WILL START TO VEER OVER THE GULF OF MEXICO LATE SUN NIGHT. THIS WILL DECREASE WINDS FUNNELING INTO THE GULF OF TEHUANTEPEC AND WINDS WILL DIMINISH BELOW GALE FORCE MON MORNING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A SURFACE TROUGH EXTENDS FROM 10N85W TO 06.5N92W TO 07N99W. THE ITCZ EXTENDS FROM 07N100W TO 07.5N109W TO BEYOND 05N140W. WIDELY SCATTERED TO SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 210 NM N AND 150 NM S OF AXIS W OF 109W. ...DISCUSSION... A 1024 MB HIGH IS CENTERED ACROSS NE PORTIONS NEAR 28N123W AND EXTENDS A RIDGE SE TO NEAR 15N105W AND SW TO BEYOND 18N150W. THE PRESSURE GRADIENT BETWEEN THE AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS SUPPORTING FRESH TO STRONG TRADES FROM 08.5N TO 16N BETWEEN 116W AND 127W. THE HIGH PRESSURE WILL REMAIN OVER THE NORTHERN WATERS AND MAINTAIN A GRADUALLY SHRINKING ZONE OF FRESH TO LOCALLY STRONG WINDS N OF THE ITCZ THROUGH MONDAY. NW SWELL IS CONTINUING TO PROPAGATE THROUGH THE FORECAST WATERS THIS EVENING WHILE SLOWLY SUBSIDING...AND IS DOMINATING SEAS ACROSS THE DISCUSSION AREA. COMBINED SEAS 8 FT OR GREATER CONTINUE TO AFFECT MUCH OF THE FORECAST WATERS W OF 100W...WITH PEAK SEAS OF 10-13 FT COVERING A LARGE AREA FROM 06.5N TO 25N BETWEEN 105W AND 125W THIS EVENING. SEAS WILL CONTINUE TO GRADUALLY SUBSIDE OVER THE NEXT COUPLE OF DAYS AND THE COVERAGE OF COMBINED SEAS 8 FT OR GREATER WILL SIGNIFICANTLY DECREASE. THE PRESSURE GRADIENT BETWEEN THE RIDGE OF HIGH PRESSURE AND LOWER PRESSURE OVER MEXICO WILL STRENGTHEN WINDS OFF THE COAST OF SW MEXICO TONIGHT...AS WELL AS INSIDE THE GULF OF CALIFORNIA...AND ALONG W COASTAL PORTIONS OF BAJA CALIFORNIA SUR. THESE WINDS WILL DIMINISH LATE SUN AFTERNOON AS THE PRESSURE GRADIENT WEAKENS...THEN BECOME FRESH TO STRONG AGAIN LATE SUN NIGHT THROUGH MON AS THE HIGH STRENGTHENS SLIGHTLY. GAP WINDS... GULF OF PAPAGAYO...WINDS WILL PULSE TO 20 TO 25 KT OVER THE GULF OF PAPAGAYO SUNDAY NIGHT THROUGH MON AS HIGH PRES BUILDS ACROSS THE SE CONUS...THE EASTERN GULF OF MEXICO AND THE WESTERN CARIBBEAN. THIS GAP WIND FLOW WILL WEAKEN MON EVENING AND THEN INCREASE AGAIN TO AROUND 20 KT MON NIGHT THROUGH MIDDAY TUESDAY. THE BUILDING HIGH PRESSURE WILL ALSO PROMOTE FRESH NORTHERLY WINDS TO AROUND 20 KT BLOWING ACROSS PANAMA AND ACROSS AND DOWNSTREAM OF THE GULF OF PANAMA...TO AROUND 06N SUN NIGHT THROUGH MONDAY. SEAS ARE EXPECTED TO BUILD TO 5-7 FT DOWNSTREAM DURING THIS TIME. $$ STRIPLING