{"msg": "150\nAXPZ20 KNHC 180131\nTWDEP\nTropical Weather Discussion\nNWS National Hurricane Center Miami FL\n0405 UTC Tue Aug 18 2026\nTropical Weather Discussion for the eastern Pacific Ocean from\n03.4S to 30N, east of 120W including the Gulf of California, and\nfrom the Equator to 30N, between 120W and 140W. The following\ninformation is based on satellite imagery, weather observations,\nradar, and meteorological analysis.\nBased on 0000 UTC surface analysis and satellite imagery through\n0100 UTC.\n...SPECIAL FEATURES...\nGulf of Tehuantepec Gale Warning: A very tight local pressure\ngradient is present over the Gulf of Tehuantepec area in the \nwake of a departing tropical wave with a tight ridge of high \npressure nosing down eastern to southeastern Mexico, as well as a\nsurface trough to the northeast over the western Yucatan \nPeninsula. This pressure is likely supporting minimal gale-force\nnortherly gap winds in the Gulf of Tehuantepec, with seas in the\nprocess of building to 8 to 10 ft. Winds are forecast to diminish\nbelow gale-force to fresh to strong by early Tue. Please, refer\nto the latest NWS High Seas Forecast available at website:\nhttps://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.\n...TROPICAL WAVES...\nThe axis of a tropical wave is near 78W from 03N near the border\nof Ecuador and Colombia northward to across eastern Panama near \nthe border with Colombia, and continuing into the Caribbean Sea \nto near western Jamaica, moving westward at around 10 kt. \nScattered to numerous moderate and isolated strong convection is \nnoted from 02N to 12N between 77W and 93W.\nThe axis of a tropical wave is near 98W from just western \noffshore Oaxaca southward to near the Equator, moving slowly \nwestward at around 5 kt. Scattered moderate isolated strong \nconvection is noted from 06N to 13N between 96W and 103W. An area\nof low pressure is forecast to form several hundred nautical \nmiles south of the coast of southern Mexico around the end of the\nweek. Gradual development of this system is likely thereafter, \nand a tropical depression is expected to form this weekend while \nthe system moves west- northwestward, remaining well offshore of \nMexico.\nThe axis of a tropical wave is near 126W from 01N to 17N, moving\nwestward at around 10 kt. Scattered moderate isolated strong \nconvection is noted from 06N to 14N between 114W and 136W. A\nbroad area of low pressure is expected to form well to the east-\nsoutheast of the Hawaiian Islands during the latter part of this \nweek. Environmental conditions appear conducive for gradual \ndevelopment of this system, and a tropical depression could form \ntowards the end of the week or over the weekend while the system \nmoves generally westward across the western portion of the east \nPacific and into the central Pacific.\n...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...\nThe monsoon trough extends from 1009 mb low pressure near the\nborder of NW Venezuela and northern Colombia at 09N72W to along \nnorthern Panama to across Costa Rica and into the Pacific near\n09N84W to 06.5N108W. The ITCZ extends from 06.5N108W to\n08.5N122W, then resumes west of a tropical wave from 09N129W to\nbeyond 08N140W. Other than the convection described above with\nthree tropical waves, scattered moderate isolated strong is noted\nfrom 00N to 02.5N between 129W and 138W.\n...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...\nSee the Special Features section above for details on a Gale\nWarning in effect in the Gulf of Tehuantepec for the overnight\nhours. An area of 7 to 9 ft seas is found just southwest of the\nGulf of Tehuantepec, a combination of earlier fresh to strong\nwinds to the east near the Gulf of Papagayo, the Gulf of\nTehuantepec winds, and background SW swell.\nSee Tropical Waves section above for information on a tropical\nwave that has a potential for tropical development offshore\nMexico at the end of this week.\nSeas are 4 to 6 ft across the remainder of the offshore waters,\nexcept 1 to 3 ft in the Gulf of California. Moderate to fresh \nNW-N winds are found offshore Baja California from Punta Eugenia \nnorthward, locally strong near Punta Eugenia. Winds are moderate \nor weaker across the remainder of the offshore waters, except \ndeveloping fresh to strong winds along the coast between Cabo \nCorrientes and the entrance to the Gulf of California where a \nstrong thunderstorm complex is in the process of moving slightly \noffshore into the Gulf of California and adjacent areas. \nScattered thunderstorms are noted from 19N to 27N between Mexico \nand 109.5W.\nFor the forecast, the pressure gradient between high pressure \nover the Gulf of America and relatively lower pressure south of \nMexico will continue to induce pulses of strong north winds over \nthe Gulf of Tehuantepec through Wed night, to minimal gale-force\novernight tonight into early Tue, with moderate to fresh pulses \nstarting Thu. Seas will occasionally build to rough with the\nfresh to strong or stronger winds. A surge of strong SE winds \nwill move from north of Cabo Corrientes into the southern\nand central Gulf of California tonight into early Tue, \nassociated with a complex of convection. Winds and seas may build\nacross the outer offshore waters of southwestern Mexico by the \nend of the week into the upcoming weekend in association with a \npossibly developing area of low pressure beyond the offshore \nwaters.\n...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, \nAND WITHIN 750 NM OF ECUADOR...\nSee Tropical Waves section above for information on a tropical\nwave producing heavy rainfall over portions of Colombia, Panama\nand areas northwestward, with heavy thunderstorms also over the\nadjacent offshore waters as described above.\nDeveloping offshore easterly fresh to strong winds are in the\nimmediate Gulf of Papagayo. Winds are moderate or weaker elsewhere\nnorth of the monsoon trough, and moderate to fresh south of the \nmonsoon trough. Seas are 4 to 7 ft in long-period SW swell, \nexcept 7 to 9 ft southwest of the Galapagos Islands. \nFor the forecast, the pressure gradient between high pressure \nover the western Caribbean and relatively lower pressure over \nCentral America will lead to pulsing strong to near gale-froce \nnortheast to east gap winds over the Papagayo region, with \nresultant rough seas. Moderate to fresh associated winds will\nextend well downwind across the outer offshore waters of El\nSalvador and Guatemala at times. Moderate to fresh southerly \nwinds will pulse south of the monsoon trough through tonight. \nLarge southerly swell will impact waters mainly from Ecuador to \nthe Galapagos Islands through Wed night, largest expected through\nTue night.\n...REMAINDER OF THE AREA...\nSee Tropical Waves section above for information on two tropical\nwaves that have potential for tropical development later this \nweek.\nModerate to fresh E winds are noted from 09N to 20N between 121W\nand 136W associated with the tropical wave at 126W, with similar\nwinds from 20N to 28N between 129W and 138W. Moderate to fresh \nwinds and rough seas are also found south of the monsoon trough \nbetween 90W and 126W. Winds are moderate or weaker across the \nremainder of the open waters, except locally fresh near the \neastern tropical wave at 98W with locally rough seas. Seas are 4 \nto 7 ft across the remainder of the open waters. For the \nforecast, regardless of tropical development, the tropical waves \ndescribed in the above section will bring some increasing winds \nand seas to area waters. Away from these waves, little change is \nexpected in marine weather through the week.\n", "title": "Eastern Pacific Tropical Weather Discussion", "id": "1202409856237633543", "issued": "2026-08-18T04:05:00Z", "wmo": "AXPZ20", "source": "NOAA/NWS National Hurricane Center, received via the National Weather Wire Service", "page": "https://hurricane.terrapin.com/text/1202409856237633543"}