000 AXPZ20 KNHC 202201 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN DEC 20 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 1500 UTC. ...SPECIAL FEATURE... A GALE WARNING REMAINS IN EFFECT FOR THE GULF OF TEHUANTEPEC. RECENT SCATTEROMETER PASSES SHOWED NORTHERLY WINDS IN THE 30-40 KT RANGE DOWNSTREAM OF THE GULF TO NEAR 13N95W WHILE AN ALTIMETER PASS INDICATED SEAS TO 17 FT NEAR 15N95W. THESE WINDS WILL GRADUALLY DIMINISH OVER THE NEXT 24-36 HOURS AS THE COOL AND DRY MASS OF AIR OVER THE GULF OF MEXICO MODIFIES AND SHIFTS EASTWARD. WINDS ARE EXPECTED TO DIMINISH BELOW GALE FORCE BY EARLY MON MORNING...AND TO 20 TO 25 KT BY MON EVENING. THE PLUME OF SHORT PERIOD NE SEAS GENERATED FROM THIS STRONG GAP WIND EVENT CONTINUES TO MIX WITH LONGER PERIOD NW SWELL COVERING ROUGHLY THE WATERS SOUTH OF 14N BETWEEN 92W AND 110W. WINDS WILL DIMINISH TO 20 KT OR LESS AND SEAS SUBSIDE TO LESS THAN 8 FT BY LATE MON/EARLY TUE. LOOKING AHEAD...GLOBAL MODELS ARE NOT INDICATING ANY STRONG GAP WINDS THROUGH THE GULF OF TEHUANTEPEC FOR THE REMAINDER OF THE WEEK. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A SURFACE TROUGH EXTENDS FROM 07N77W TO 04N90W. THE ITCZ AXIS EXTENDS FROM 05N96W TO 04N110W TO 05N120W TO 02N137W TO BEYOND 02N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED WITHIN 60 NM S OF TROUGH AXIS E OF 82W. SCATTERED MODERATE CONVECTION IS OBSERVED WITHIN 180 NM AND 60 NM BETWEEN 120W AND 125W AND W OF 135W. ...DISCUSSION... N OF 15N E OF 120W...A COLD FRONT REACHES FROM THE NORTHERN GULF OF CALIFORNIA ACROSS THE MIDDLE SECTIONS OF BAJA CALIFORNIA NORTE THEN SW TO NEAR 24N125W. THE SUPPORTING UPPER DYNAMICS ARE LIFTING TO THE NE OF THE AREA...LEAVING THE FRONT TO STALL AND DISSIPATE THROUGH EARLY MON. THE MAIN FORECAST ISSUE WILL BE ANOTHER ROUND OF LONGER PERIOD NW SWELL ACCOMPANYING THE FRONT MOVING INTO THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA LATE SUNDAY THROUGH MONDAY WITH SEAS TO 9 FT COVERING THE AREA WEST OF 110W INCLUDING THE REVILLAGIGEDO ISLANDS BY LATE MON. LOOKING AHEAD...THE SWELL WILL START TO SUBSIDE BELOW 8 FT THROUGH MID WEEK...JUST AS ANOTHER COLD FRONT MOVES INTO THE REGION FROM THE NW. STRONG NW WINDS WILL FOLLOW THE FRONT WITH 8 TO 11 FT SEAS IMPACTING THE BAJA CALIFORNIA NORTE COAST THROUGH WED. S OF 15N E OF 110W...BUILDING HIGH PRES ACROSS THE GULF OF MEXICO AND THE WESTERN ATLC WILL SUPPORT GALE FORCE TRADE WINDS IN THE SOUTH-CENTRAL CARIBBEAN. THESE WINDS ARE FUNNELING THROUGH THE GAPS ACROSS CENTRAL AMERICA INTO THE EASTERN PACIFIC ALLOWING WINDS TO INCREASE ACROSS THE GULF OF PAPAGAYO AND THE GULF OF FONSECA. AN EARLIER SCATTEROMETER SATELLITE PASS INDICATED WINDS TO GALE FORCE NEAR THE COAST OF SOUTHERN NICARAGUA JUST TO THE NORTH OF THE GULF OF PAPAGAYO. THIS MAY HAVE BEEN PARTLY INFLUENCED BY OVERNIGHT DRAINAGE CONDITIONS WHICH HAVE SINCE DIMINISHED...THUS WINDS ARE LIKELY JUST BELOW GALE FORCE IN THAT AREA CURRENTLY. EXPECT NE WINDS OF 20-30 KT AND SEAS OF 8-12 FT EXTENDING DOWNSTREAM OF BOTH GULFS TO NEAR 09N92W. IN ADDITION TO THE GAP WINDS...SHOWERS AND THUNDERSTORMS WILL BE ACTIVE MAINLY OVERNIGHT OFF THE COAST OF COLOMBIA THROUGH THE PERIOD. ELSEWHERE...RECENT SCATTEROMETER SATELLITE PASSES AND TOGA BUOY OBSERVATIONS INDICATED A COUPLE OF AREAS OF 20 TO 25 KT FROM 05N TO 20N W OF 130W.. THE TRADE WINDS FLOW WILL INCREASE IN EXTENT TONIGHT AS HIGH PRES BUILDS N OF THE AREA. SEAS WILL BUILD TO 13 FT BY MONDAY OVER THIS REGION DUE IN PART TO THE NE TRADE WINDS BUT ALSO INCLUDING A NEW ROUND OF LONGER PERIOD NW SWELL IN THE REGION. THE LOW LEVEL TRADE WIND CONVERGENCE IS ASSISTING DEVELOPMENT OF SCATTERED SHOWERS AND A FEW THUNDERSTORMS ALONG THE ITCZ EAST OF 120W. LOOKING AHEAD...LITTLE CHANGE INTO MID WEEK WITH TRADES DIMINISHING SLIGHTLY BY LATE IN THE WEEK. $$ GR