000 AXPZ20 KNHC 271005 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE JAN 27 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...A PERSISTENT TIGHT PRES GRADIENT ACROSS SOUTHEASTERN MEXICO IS PRODUCING A LONG DURATION EVENT OF N TO NE 30-40 KT WINDS THROUGH THE ISTHMUS OF TEHUANTEPEC AND THE GULF WITHIN 45 NM EITHER SIDE OF A LINE FROM 16N95W TO 15N95W TO 14N96W. SEAS THERE ARE IN THE 11-17 FT RANGE. EARLIER OBSERVATIONS AS REPORTED EARLY MON EVENING AND DURING THE OVERNIGHT HOURS FROM SHIPS "ZCDI4"..."SLKR"...AND "ZOAY4" VERIFIED THE GALE WIND CONDITIONS WITH SHIP "ZCDI4" NEAR 16N95W REPORTING 42 KT AT 00 UTC...SHIP "SLKR" NEAR 14N95W REPORTING 40 KT AT 06 UTC AND SHIP "ZOAY4" NEAR 14N96W REPORTING 36 KT ALSO AT 06 UTC. A LARGE AREA OF N-NE 20-30 KT WINDS IS ELSEWHERE WITHIN 75 NM OF A LINE FROM 16N95W TO 15N95W TO 12N98W WITH SEAS OF 10-15 FT. NE SWELLS THAT HAVE PROPAGATED DOWNSTREAM FROM THIS EVENT OVER THE PAST FEW DAYS ARE COMBINING WITH LONG PERIOD NW SWELLS FROM 08N- 14N BETWEEN 94W-101W...AND ALSO S OF 11N BETWEEN 101W-112W. THE COMBINATION OF THESE SWELLS IS RESULTING IN SEAS TO 9 FT. THE HIGH PRES TIED TO CULPRIT TIGHT PRES GRADIENT WILL GRADUALLY WEAKEN THROUGH THU ALLOWING FOR THE GALE WINDS TO DIMINISH TO MINIMAL THRESHOLD WITH MAX SEAS IN THE GULF EXPECTED AT AROUND 13 FT AT THAT TIME. GULF OF PAPAGAYO GALE WARNING...A TIGHTENING PRES GRADIENT ACROSS THE WESTERN CARIBBEAN SEA IS EXPECTED TO INCREASE THE PRESENT NE 20-25 KT THROUGH THE GULF OF PAPAGAYO TO 30 KT BY LATE TONIGHT...AND TO GALE FORCE OF 30-35 KT BY LATE WED NIGHT WITH SEAS BUILDING FROM 9 TO 12 FT AT THAT TIME. MEAN ENSEMBLE GUIDANCE FROM THE GFS MODEL SUGGESTS THAT THIS GALE EVENT IS LIKELY TO OCCUR...BUT SHOULD BE RATHER SHORT-LIVED. FRESH TO STRONG WINDS WILL EXTEND DOWNWIND FROM THE GULF ELSEWHERE FROM 09N-13N E OF 88W...INCLUDING THE GULF OF FONSECA AND ALSO WITHIN 60 NM OF A LINE FROM 09N88W TO 08N90W WITH SEAS OF 8-10 FT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 02N78W TO 03N84W TO 05N89W WHERE SCATTEROMETER DATA SUGGESTS A TRANSITION TO THE ITCZ CONTINUING TO 06N102W TO 07N112W TO 07N122W TO 08N130W TO 06N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM N OF THE TROUGH BETWEEN 78W-79.5W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF THE ITCZ BETWEEN 93W-94.5W. ...DISCUSSION... ALOFT...A LONGWAVE TROUGH STRETCHES FROM 32N133W SSE TO 23N130W...AND TO NEAR 11N123W. BROAD SCALE RIDGING IS NOTED ON EITHER SIDE OF THE TROUGH WITH A RIDGE AXIS STRETCHING FROM THE TEXAS PANHANDLE SEWD TO SE MEXICO...AND TO ACROSS CENTRAL AMERICA. AT THE SURFACE...THE PREVIOUS COLD FRONT THAT MOVED INTO THE FAR NW PORTION OF THE AREA HAS STALL ALONG A POSITION FROM 31N135W TO 23N140W. A TIGHT PRES GRADIENT W OF THE FRONT IS INDUCING N- NE WINDS OF 20-25 KT THERE WITH SEAS IN THE RANGE OF 9-10 FT. THE FRONT IS FORECAST TO WEAKEN THROUGH LATE TONIGHT WITH THE GRADIENT BEHIND IT SLACKENING. THIS WILL DECREASE THESE WINDS TO 15 KT WITH SEAS JUST UNDER 8 FT. E OF THE FRONT WEAK HIGH PRES OF 1019 MB CENTERED NEAR 33N123W EXTENDS A RIDGE SSE TO NEAR 11N113W. THE ASSOCIATED PRES GRADIENT IS WEAK AS INDICATED IN ASCAT PASSES FROM JUST AFTER 04 UTC AND NEAR 0530 UTC THAT DISPLAYED MOSTLY GENTLE WINDS N OF 11N AND TO THE E OF THE FRONT. NE-E FRESH WINDS ARE S OF 11N...EXCEPT IN REGIONS OF GAP WINDS AS DESCRIBED ABOVE. LONG PERIOD NW SWELLS DOMINATE MUCH OF THE FORECAST WATERS AND ARE CURRENTLY MIXING WITH THE SHORT PERIOD WIND WAVES GENERATED IN THE AFOREMENTIONED GAP WIND REGIONS OF TEHUANTEPEC AND PAPAGAYO. ADDITIONAL PULSES OF NW SWELLS RELATED TO THE AFOREMENTIONED COLD FRONT ARE PROPAGATING SEWD OVER AN AREA TO THE N OF 14N AND W OF ABOUT 122W WITH RESULTANT MAX SEAS IN THE 9-10 FT. SWELL ENERGY IS FORECAST TO GRADUALLY DISSIPATE THROUGH WED ALLOWING FOR SEAS TO SUBSIDE TO LESS THAN 8 FT. GAP WINDS... SEE SPECIAL FEATURES FOR DETAILS. OTHERWISE...FRESH TO STRONG N WINDS ARE FUNNELING THROUGH THE GULF OF PANAMA FROM THE WESTERN CARIBBEAN SEA REACHING TO NEAR 04N BETWEEN 79W-81W. THESE WINDS WILL CHANGE LITTLE THROUGH WED NIGHT WITH SEAS THERE MAXING OUT TO 8 OR 9 FT. $$ AGUIRRE