000 AXPZ20 KNHC 241525 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN JAN 24 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1400 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...HIGH PRES ACROSS NW MEXICO HAS WEAKENED THIS MORNING...DIMINISHING THE PRES GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC. WINDS ARE BELIEVED TO HAVE BEEN MINIMAL GALE FORCE AROUND SUNRISE THIS MORNING AND WILL DROP BELOW GALE FORCE BY MIDDAY. WINDS WILL CONTINUE TO DIMINISH BELOW THE ADVISORY CRITERIA OF 20-25 KT EARLY MON AS THE DRIVING HIGH PRES OVER THE SE UNITED STATES SHIFTS NE TO THE CAROLINA COAST. MAXIMUM SEAS CURRENTLY IN THE RANGE OF 9-14 FT WILL SUBSIDE BELOW 8 FT BY EARLY MON. GULF OF PAPAGAYO GALE WARNING...A COLD FRONT OVER THE SW CARIBBEAN HAS USHERED IN HIGH PRES BEHIND IT OVER CENTRAL AMERICA. THE GRADIENT BETWEEN THIS HIGH PRES AND THE ITCZ TO THE S HAS BROUGHT WINDS TO GALE FORCE FUNNELING INTO THE GULF OF PAPAGAYO. THE 0330 UTC ASCAT-B PASS FROM 0330 UTC SHOWED A SMALL AREA OF 30-35 KT WINDS IN THE GULF OF PAPAGAYO E OF 87W...PRIOR TO THE PERIOD OF PEAK NOCTURNAL DRAINAGE FLOW. GALE CONDITIONS ARE EXPECTED TO DIMINISH BY MIDDAY TODAY. THE HIGH PRES TO THE N WILL ERODE OVER THE NEXT TWO DAYS...GRADUALLY DIMINISHING THE PRESSURE GRADIENT. MAXIMUM WINDS TO 30 KT ARE EXPECTED DURING THE PERIOD OF PEAK NOCTURNAL DRAINAGE LATE TONIGHT INTO EARLY MON MORNING...AND WINDS TO 25 KT ARE EXPECTED LATE MON NIGHT INTO EARLY TUE. THE NE SWELL FROM THIS EVENT IS MIXING WITH THE NE SWELL FROM TEHUANTEPEC AND LONG-PERIOD NW SWELL TO MAKE FOR A WIDESPREAD AREA OF SEAS IN THE 8-10 FT RANGE WHICH SHOULD SUBSIDE TONIGHT THROUGH EARLY TUE. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS WAS ANALYZED FROM 01N83W TO 05N88W TO 02N96W TO 05N110W TO 04N124W TO 04N132W TO 03N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 100W-108W. ...DISCUSSION... THE LEADING EDGE OF A LONG-PERIOD SWELL TRAIN...WITH PERIODS IN THE 18-20 SECOND RANGE...IS MAKING ITS WAY S ALONG THE COAST OF SOUTHERN MEXICO THIS MORNING. IT IS EXPECTED TO REACH COSTA RICA AND THE GALAPAGOS ISLANDS OVERNIGHT MON NIGHT AND COULD GENERATE HIGH SURF AND POSSIBLY DANGEROUS CONDITIONS ENTERING AND EXITING HARBORS. A WIDESPREAD AREA OF SEAS IN THE 8-11 FT RANGE IN THIS NW SWELL LIES OVER THE FORECAST AREA W OF 108W. THE SEAS WILL GRADUALLY SUBSIDE THROUGH THE PERIOD...WITH SEAS OVER 8 FT IN NW SWELL CONFINED TO S OF 10N BETWEEN 94W-120W BY SUNRISE TUE. THE SUBTROPICAL RIDGE ACROSS THE AREA IS DOMINATED BY THE 1026 MB HIGH PRES CENTER LOCATED NEAR 32N130W. SCATTEROMETER DATA SHOWED FRESH TO STRONG NE WINDS N OF THE ITCZ AND W OF A SURFACE TROUGH NEAR 130W EARLY THIS MORNING. THIS WEAK...FAST- MOVING...LOW-LEVEL TROUGH IS TIGHTENING THE PRES GRADIENT OVER SW WATERS BETWEEN IT AND THE SUBTROPICAL RIDGE. THE TROUGH WAS ANALYZED FROM 04N-10N ALONG 133W AT 1200 UTC...WITH FRESH TO STRONG TRADES BELIEVED TO BE W OF THE TROUGH FROM 05N-09N. THE TROUGH WILL MOVE W OF THE AREA BY TONIGHT AS THE HIGH PRES TO THE N SHIFTS NORTHEASTWARD...DIMINISHING THE PRES GRADIENT AND ALLOWING WINDS TO DIMINISH TO A FRESH BREEZE. A NEW COLD FRONT WILL APPROACH THE NW WATERS...INCREASING S-SW WINDS AND BUILDING SEAS TO THE ADVISORY CRITERIA OF 20-25 KT AND 8 FT...RESPECTIVELY...MON MORNING. THE FRONT WILL WEAKEN AS IT SLOWLY APPROACHES THE AREA. WINDS WILL DIMINISH BELOW A FRESH TO STRONG BREEZE OVERNIGHT MON NIGHT AS THE SWELL CONTINUES TO BUILD SEAS SOUTHEASTWARD. SEAS ARE EXPECTED TO REACH AS HIGH AS 14 FT OVER NW WATERS BY LATE MON NIGHT AS THE DISSIPATING FRONT MOVES INTO THE AREA. GULF OF PANAMA...THE AFOREMENTIONED COLD FRONT IN THE SW CARIBBEAN HAS USHERED 20-30 KT N WINDS THROUGH PANAMA INTO THE GULF OF PANAMA AND SOUTHWARD TO 03N THIS MORNING. THE HIGH PRES OVER CENTRAL AMERICA AND THE WESTERN CARIBBEAN SEA WILL WEAKEN OVER THE NEXT TWO DAYS...WITH WINDS EXPECTED TO DIMINISH TO A FRESH TO STRONG BREEZE THIS EVENING AND THE EXTENT OF THE WINDS EXPECTED TO SHRINK NORTHWARD TO 05N THROUGH MIDDAY MON BEFORE DIMINISHING BELOW THE ADVISORY CRITERIA BY TUE MORNING. $$ SCHAUER