000 AXPZ20 KNHC 210247 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON MAR 21 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 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 AVE INITIATED A N-NE GALE FORCE WIND EVENT ACROSS THE GULF AS INDICATED EARLIER THIS EVENING BY A SHIP IN THE VICINITY OF THE GULF. IR SATELLITE IMAGERY IS REVEALING WHAT APPEARS TO BE A DEVELOPING TONGUE OF COLD WATER UPWELLING WITHIN ABOUT 80 NM S OF THE GULF. THE GALE FORCE WINDS ARE PRESENTLY IN THE RANGE OF 30-45 KT WITH SEAS OF 10-16 FT. THE RESULTANT SEAS WILL BUILD TO THE RANGE OF 11-19 FT NEAR 09Z MON AND TO 20 FT BY EARLY ON 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 WITHIN THIS AREA WILL BE IN THE RANGE OF 10-16 FT BY MON AFTERNOON...AND SUBSIDE SLIGHTLY 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/TROUGH... TROUGH FROM 08N83W TO 04N89W TO 04N95W...THEN TRANSITIONS TO THE ITCZ AXIS EXTENDS TO 05N108W TO 04N117W TO 01N125W TO 03N132W TO 03N140W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 115W-119W...AND WITHIN 60 NM OF THE TROUGH BETWEEN 85W-89W. ...DISCUSSION... UPPER LEVELS... A STRONG UPPER JET STREAM BRANCH EXTENDS FROM 14N137W TO 18N120W TO 19N109W AND ENE ACROSS CENTRAL MEXICO...AND NE FROM THERE ACROSS THE GULF OF MEXICO. THE JET IS TRANSPORTING AMPLE MOISTURE IN THE FORM OF BROKEN HIGH CLOUDS...OBSERVED AS TRANSVERSE BANDING IN SATELLITE IMAGERY WITHIN 240 NM TO ITS S. SURFACE... A 1021 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 32N126W TO 28N131W 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 MUCH HIGHER SEAS OF 12-17 FT NW OF A LINE FROM 32N134W TO 28N140W. THE NW SWELL WILL CONTINUE TO PROPAGATE SEWD WITH THE LEADING EDGE OF THE SWELL TRAIN REACHING FROM JUST W OF BAJA CALIFORNIA SUR TO 12N117W TO 05N124W TO 01N130W TO THE EQUATOR AT 140W BY EARLY TUE EVENING. ON TUE EVENING...SEAS OF 10-12 FT ARE FORECAST IN THE NE PORTION N OF 26N E OF 125W. EXPECT HAZARDOUS MARINE CONDITIONS ALONG THE BAJA CALIFORNIA NORTE TUE...SPREADING SE TO THE CENTRAL COAST OF THE PENINSULA BY LATE TUE. THE FRONT IS FORECAST TO DISSIPATE BY LATE MON NIGHT. AT THAT TIME...SEAS OF 11-13 FT ARE FORECAST N OF 27N BETWEEN 119W-126W. OTHER GAP WIND EVENTS... A GULF OF PAPAGAYO GAP WIND EVENT WITH 20-25 KT NE WINDS IS SUGGESTED BY 10 METER MODEL GUIDANCE TO TAKE PLACE NEAR OR AT 12Z MON AS HIGH PRES BUILDS SEWD ACROSS THE WESTERN CARIBBEAN AND NORTHERN CENTRAL AMERICA AND INTERACTS WITH LOWER PRES OVER PANAMA AND COLOMBIA. 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 INCLUDE THE GULF OF PAPAGAYO. SEAS ARE FORECAST TO BUILD FROM 8 FT ON MON TO 9-11 FT. 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-13N BETWEEN 93W AND 96WW...AND FROM 03N-14N BETWEEN 96W-112W BY TUE NIGHT. $$ AGUIRRE