000 AXPZ20 KNHC 281005 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU JAN 28 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...A VERY TIGHT PRES GRADIENT HAS SETTLED IN ACROSS SOUTHEASTERN MEXICO AND THE ISTHMUS OF TEHUANTEPEC IN ASSOCIATION WITH A STRONG 1030 MB HIGH CENTER LOCATED OVER E CENTRAL MEXICO. THIS SYNOPTIC SET UP HAS INITIATED A GALE WIND EVENT OF N-NE 30-35 KT WINDS THROUGH THE GULF. WINDS ARE EXPECTED TO INCREASE TO 30-40 KT EARLY THIS AFTERNOON AS THE THE PRESS GRADIENT TIGHTENS FURTHER AND CONTINUE INTO LATE FRI MORNING. SEAS OF 9-14 FT WILL BUILD TO 10-16 FT BY LATE TONIGHT. THE TIGHT PRES GRADIENT WILL BEGIN TO WEAKEN FRI AFTERNOON ALLOWING FOR THE GALE WINDS TO DIMINISH TO 30-35 KT...AND TO JUST BELOW GALE FORCE BY EARLY FRI EVENING. SEAS WILL ARE FORECAST TO SUBSIDE TO 8-10 FT BY EARLY FRI EVENING. NE SWELL RESULTING FROM THIS EVENT WILL SPREAD SW AWAY FROM THE TEHUANTEPEC REGION...AND MIX WITH LONG PERIOD NW SWELL OVER AN AREA FROM 08N-14N BETWEEN 93W-106W FRI AFTERNOON THROUGH EARLY FRI EVENING. WAVEWATCH INDICATES THAT THIS SWELL WILL STILL CONSIST OF A NE AND NW COMPONENT OVER AN AREA FROM 06N-14N BETWEEN 95W-113W BY LATE FRI NIGHT AND INTO SAT WITH SEAS OF 8-9 FT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS EXTENDS FROM 05N94W TO 06N101W WHERE IT BRIEFLY ENDS...THEN RESUMES AT 05N104W TO 04N110W TO 05N120W TO 04N130W TO BEYOND 04N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS W OF 137W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF THE AXIS BETWEEN 94W-97W... WITHIN 60 NM OF THE AXIS BETWEEN 108W-113W...AND WITHIN 90 NM N OF AXIS BETWEEN 114W-117W. ...DISCUSSION... A SHARP UPPER TROUGH AXIS EXTENDING FROM SOUTHERN CALIFORNIA TO 18N125W AND TO NEAR 04N127W IS PRECEDED BY AMPLE DEEP TROPICAL MOISTURE IN THE FORM OF OVERCAST MULTILAYERED CLOUDS THAT COVER THE AREA FROM 09N TO 24N. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE POSSIBLE UNDERNEATH THESE CLOUDS WITH THE EXISTENCE OF A STRONG SUBTROPICAL JET STREAM BRANCH NOTED E OF THE TROUGH FROM 12N TO 18N...ENHANCED BY THE ONGOING EL NINO EVENT. THE MID/HIGH CLOUDINESS IS BEING ADVECTED ENE TO ACROSS CENTRAL MEXICO...AND ACROSS THE GULF OF MEXICO. A STRONG 1030 MB HIGH CENTERED AT 31N126W HAS A RIDGE AXIS EXTENDING SE TO NEAR 20N115W...AND ANOTHER RIDGE EXTENDING SW TO BEYOND THE AREA AT 27N140W. THIS HIGH IS FORECAST TO MOVE SLIGHTLY SW OVER THE NEXT 24 HOURS WHILE IT WEAKENS A LITTLE. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN THE VICINITY OF THE ITCZ HAS INCREASED SINCE YESTERDAY ALLOWING FOR AN AREA OF STRONG TRADE NE TO E WINDS TO MATERIALIZE FROM 04N TO 10N W OF 128W WITH SEAS IN THE 9-12 FT RANGE. THE 0618 ASCAT PASS DEPICTED THE GENERAL AREA OF THESE WINDS. THE GRADIENT IS FORECAST TO GRADUALLY LOOSEN UP THROUGH FRI EVENING AS THE HIGH SHIFTS MORE TO THE SW AND WEAKENS SOME MORE. THIS WILL ALLOW FOR THE FRESH TO STRONG TRADES TO DIMINISH TO THE FRESH RANGE WITH SEAS OF 8-11 FT DUE TO A NW SWELL. A PERSISTENT WEAK SURFACE TROUGH IS ANALYZED ALONG A POSITION FROM 10N100W TO 02N104W. LATEST SATELLITE IMAGERY SHOWS CLUSTERS OF SCATTERED MODERATE CONVECTION WITHIN 90 NM E OF THE TROUGH FROM 08N-10N. THE TROUGH EARLIER NOTED ALONG 136W IS NOT IDENTIFIABLE AT 06 UTC. A LARGE LONG PERIOD NW SWELL WILL CONTINUE TO PROPAGATE TO THE SE ACROSS THE WATERS W OF 110W THROUGH THE REMAINDER OF THE WEEK. SIGNIFICANT WAVE HEIGHTS OF 11-13 FT ARE ACROSS THE NW CORNER WILL BE REINFORCED BY A NEW SET OF NW SWELL THIS AFTERNOON...BOOSTING FURTHER UP TO 18 FT. THE LEADING EDGE OF THIS SWELL EVENT IS CURRENTLY REACHING THE PACIFIC COAST OF BAJA CALIFORNIA...AND WILL REACH AS FAR E AS 110W TONIGHT THROUGH SAT. ROUGH WAVE ACTION PRODUCING HAZARDOUS SURF CONDITIONS CAN BE EXPECTED ALONG THE PACIFIC COAST OF BAJA CALIFORNIA FRI THROUGH SUN. GAP WINDS... GULF OF CALIFORNIA...THE STRONG NW WINDS ARE CONFINED TO S OF 28N. THESE WINDS WILL GRADUALLY DIMINISH TO MAINLY FRESH INTENSITY BY EARLY THIS AFTERNOON AS THE PRES GRADIENT BETWEEN STRONG HIGH PRES OVER THE U.S. GREAT BASIN AND SURFACE TROUGHING OVER NW MEXICO SLACKENS. SIMILAR STRONG NW-N WINDS WITH SEAS OF 8 FT ARE OVER THE ENTRANCE TO GULF...S TO NEAR 19N AND BETWEEN 107W-109W. THESE WINDS WILL LINGER INTO EARLY THIS AFTERNOON BEFORE DIMINISHING TO A MODERATE RANGE. GULF OF PAPAGAYO...STRONG NE WINDS ARE FORECAST TO START UP AGAIN FRI MORNING AS HIGH PRES SURGING SOUTHWARD ACROSS THE NORTHERN PORTION OF CENTRAL AMERICA INTERACTS WITH LOWER PRES TO ITS S OVER THE REMAINDER OF CENTRAL AMERICA AND FAR EASTERN PACIFIC WATERS. THESE WINDS WILL INCREASE TO THE STRONG RANGE FRI NIGHT INTO SAT AND SPREAD N TO NEAR 11N AND W TO NEAR 88W AS THE GRADIENT TIGHTEN FURTHER. SEAS WITHIN THE AREA OF WINDS ARE FORECAST TO BUILD TO 10 FT AT THAT TIME. $$ AGUIRRE