000 AXPZ20 KNHC 202205 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN MAR 20 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 2145 UTC. ...SPECIAL FEATURES... A RATHER STRONG COLD FRONT FOR THIS TIME OF THE YEAR IS MOVING ACROSS THE CENTRAL GULF OF MEXICO WITH ITS SOUTHERN EXTENSION DRAPED SWD TO OVER SOUTHEASTERN MEXICO. STRONG HIGH PRES SURGING S ALONG THE SIERRA MADRE ORIENTAL MOUNTAINS OF EASTERN MEXICO IN THE WAKE OF THE FRONT HAS INDUCED A VERY TIGHT PRES GRADIENT ACROSS SOUTHEASTERN MEXICO. IN ADDITION...A COOLER AIR MASS IS SPREADING S THROUGH THE CHIVELA PASS AND MIXING DOWNWARD OVER VERY WARM SEA SURFACE TEMPERATURES IN THE GULF OF TEHUANTEPEC AND VICINITY. THE STRONG WINDS MIXING DOWN FROM 30 METERS HAVE INITIATED A N-NE GALE FORCE WIND EVENT ACROSS THE GULF. THESE WINDS ARE PRESENTLY IN THE RANGE OF 30-35 KT WITH SEAS OF 8-10 FT. THESE WINDS WILL RAPIDLY INCREASE TO THE RANGE OF 30-45 KT EARLY TONIGHT WITH SEAS BUILDING TO THE RANGE OF 10-15 FT. THE SEAS WILL BUILD TO THE RANGE OF 11-20 FT BY MON AFTERNOON IN RESPONSE TO THE EXPECTED LONG DURATION OF THE 30-45 KT WINDS AS THEY ARE FORECAST TO CONTINUE INTO MON EVENING BEFORE THEY BEGIN TO SLOWLY SUBSIDE. A LARGE SWATH OF N-NE 20-30 KT WINDS WILL SPREAD S AND SW FROM THE GULF TO NEAR 100W MON AFTERNOON. SEAS S WITHIN THIS AREA WILL BE IN THE RANGE OF 10-16 FT BY MON AFTERNOON...AND SUBSIDE TO ABOUT 10-13 FT BY TUE AFTERNOON AT WHICH WIND GUIDANCE FROM THE GFS/NAM MODELS INDICATES THAT THE GALE FORCE WINDS WILL DROP BELOW GALE FORCE. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFEP2/ FZPN03 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS EXTENDS FROM 05N95W TO 06N108W TO 05N118W TO 04N125W TO 04N134W TO 04N140W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 107W-110W. SCATTERED MODERATE ISOLATED/STRONG CONVECTION IS E OF THE ITCZ WITHIN 60 NM EITHER SIDE OF A LINE FROM 07N83W TO 05N87W. ...DISCUSSION... A 1022 MB HIGH PRES IS CENTERED NEAR 27N128W WITH A RIDGE AXIS EXTENDING SE TO NEAR THE REVILLAGIGEDO ISLANDS. THE OVERALL PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRES TO THE S WITHIN THE ITCZ REGION IS SUPPORTING MODERATE TO LOCALLY FRESH NE TRADES S OF 18N W OF ABOUT 128W WITH SEAS IN THE RANGE OF 8-9 FT DUE TO A NW-N SWELL. SIMILAR WIND SPEEDS ARE ALSO NOTED JUST OFF THE BAJA CALIFORNIA PENINSULA DUE TO THE PRES GRADIENT BETWEEN THE RIDGE AND A TROUGH ALONG THE NW COAST OF MAINLAND MEXICO. SEAS ACROSS THE PACIFIC WATERS OF BAJA ARE GENERALLY RANGED 5-8 FT IN NW SWELL...BUT WILL SLOWLY SHIFT SWD THROUGH MON WHILE SUBSIDING. A WEAKENING COLD FRONT IS OVER THE NW PORTION OF THE AREA FROM NEAR 32N128W TO 27N132W WHERE IT BECOMES STATIONARY SW TO 24N140W. GENTLE TO MODERATE W-NW WINDS ARE W OF THE FRONT. AN EXTENSIVE NW SWELL TRAIN IN THE WAKE OF THE FRONT HAS USHERED IN SEAS OF 8-12 FT BEHIND IT WITH HIGHER SEAS OF 12-16 FT NW OF A LINE FROM 32N127W TO 28N140W. THE NW SWELL WILL CONTINUE TO PROPAGATE SE WITH THE LEADING EDGE OF THE SWELL TRAIN REACHING A LINE FROM NEAR 28N115W TO 15N120W TO 09N121W TO 03N125W TO 01N140W BY TUE AFTERNOON. AT THAT TIME...SEAS OF 11- 13 FT ARE FORECAST N OF 27N BETWEEN 119W-126W. A GULF OF PAPAGAYO GAP WIND EVENT WITH 20-25 KT NE WINDS IS SUGGESTED BY MODEL GUIDANCE TO TAKE PLACE MON MORNING AS HIGH PRES BUILDS ACROSS THE WESTERN CARIBBEAN AND NORTHERN CENTRAL AMERICA. THE AREA OF FRESH TO STRONG NE WINDS IN THE 20-30 KT RANGE IS FORECAST TO INCREASE FROM 09N-11N E OF 88W LATE MON NIGHT TO WITHIN 90 NM EITHER SIDE OF A LINE FROM 11N86W TO 09.5N88W TO 09N91W BY EARLY TUE WITH THE 25-30 KT WINDS E OF 88W TO NCLUDING THE GULF OF PAPAGAYO. SEAS ARE FORECAST TO BUILD FROM 8 FT ON MON TO 8-10 FT BY EALRY ON TUE AND POSSIBLY SLIGHTLY HIGHER WAVEHEIGHTS. NE SWELL GENERATED BY THE COMBINED GAP WIND EVENTS IN TEHUANTEPEC AND PAPAGAYO WILL MERGE DOWNSTREAM TO PRODUCE A LARGE AREA OF SEAS GREATER THAN 8 FT FROM 05N TO 13N BETWEEN 93W AND 105W...AND FROM 06N TO 11N BETWEEN 105W AND 110W. $$ AGUIRRE