{"msg": "938\nAXPZ20 KNHC 170832\nTWDEP \nTropical Weather Discussion\nNWS National Hurricane Center Miami FL\n1005 UTC Thu Sep 17 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 0600 UTC surface analysis and satellite imagery through\n0830 UTC.\n...SPECIAL FEATURES...\nGulf of Tehuantepec Gale Warning: The pressure gradient between high pressure over\nsouthern Mexico and the eastern north Pacific monsoon trough will support\nstrong to near-gale force N to NE gap winds across the Gulf of Tehuantepec\ninto Fri. A recent scatterometer satellite pass confirmed gale force\nwinds across the Gulf of Tehuantepec, and this may persist into the\nearly morning. Winds may again reach minimal gale force briefly tonight.\nRough seas will accompany these gap winds. Winds and seas will diminish\nFri.\n...TROPICAL WAVES...\nA tropical wave is along 101W, from 06N northward to southern \nMexico, moving westward at around 10 to 15 kt. Nearby convection\nis discussed in the ITCZ/monsoon trough section below. An area \nof low pressure could form in association to this wave well \noffshore of southwestern Mexico within the next few days. \nEnvironmental conditions appear conducive for some gradual \ndevelopment, and this system could become a tropical depression \nearly next week while it moves slowly northwestward or northward.\nThere is a low chance for development in the next 48 hours, and \na high chance for tropical cyclone development within the next 7 \ndays. \nThe axis of a tropical wave is near 116W from 07N to 16N, moving\nwest at 10 to 15 kt. Nearby convection is discussed in the \nITCZ/monsoon trough section below.\n...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...\nThe monsoon trough extends from 09N79W to 08N90W to 1007 mb low\npressure near 15N129W to 10N140W. Scattered moderate convection\nis active from 02N to 06N east of 83W, and from 10N to 16N\nbetween 112W and 116W. Scattered moderate to isolated strong\nconvection from 08N to 13N between 90W and 100W.\n...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...\nPlease see Special Features section above for more on a gale \nwarning in the Gulf of Tehuantepec. \nAn afternoon scatterometer satellite pass indicated fresh S \nwinds over the northern Gulf of California, related to lower\npressure in the region. These winds are likely diminishing this\nevening. Gentle to moderate winds and 4-7 ft are noted \nelsewhere, except 1-3 ft in the central and southern Gulf.\nFor the forecast, please see the Special Features section for \ninformation about the gale warning in the Gulf of Tehuantepec. \nGentle to moderate breezes and moderate seas will persist \nelsewhere through the end of the week. Meanwhile, a tropical \nwave is producing disorganized showers and thunderstorms south of\nAcapulco. Looking ahead, environmental conditions appear \nconducive for gradual development, and there is a high chance a \ntropical depression may form late this weekend or early next \nweek while it moves north- northwestward or northward at 5 to 10 \nkt off southwest Mexico.\n...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, \nAND WITHIN 750 NM OF ECUADOR...\nFresh to strong easterly winds, and moderate to rough seas, \nprevail across the Gulf of Papagayo region, extending downstream \nto near 90W. Moderate to fresh winds extend downstream from the \nGulf of Papagayo to the outer offshore waters of El Salvador and \nGuatemala. \nFor the forecast, the pressure gradient between a ridge north of the area\nand the eastern north Pacific monsoon trough will support pulsing\nfresh to occasionally strong easterly winds and moderate to rough\nseas across the Papagayo region today, then pulsing to moderate \nto fresh thereafter. Moderate winds and seas will prevail\nelsewhere.\n...REMAINDER OF THE AREA...\nThe 1007 mb remnant low of TD Fifteen-E is centered near \n15N130W. Scattered showers and thunderstorms remain active in \nthe vicinity of the low. Fresh to strong winds, and rough seas, \nsupported by the pressure gradient between the area of low \npressure and the subtropical ridge north of the area, cover the \nwaters from 15N to 25N west of 125W. Moderate to fresh winds,\nseas to 7 ft, a scattered showers and thunderstorms are also\nactive near a 1008 mb low pressure area along the monsoon trough\nnear 12N112W. Gentle to moderate winds and 4-6 ft combined seas \nin mixed swell are noted elsewhere. \nFor the forecast, environmental conditions appear conducive for \ngradual development of the 1008 mb low pressure near 12N112W, \nand a tropical depression could form this weekend as the system \nmoves westward at around 10 kt. There is a low chance for \ndevelopment in the next 48 hours, and a medium chance for \ntropical cyclone development within the next 7 days. Farther\nwest, a broad area of fresh to strong NE to E winds and moderate\nto rough seas in N swell will persist through the remainder of \nthe week from 15N to 25N west of 125W. Also, as described in the \ntropical wave section above, there is some potential for tropical\ncyclone development associated with a tropical wave near 101W.\n", "title": "Eastern Pacific Tropical Weather Discussion", "id": "1210985918504108034", "issued": "2026-09-17T10:05:00Z", "wmo": "AXPZ20", "source": "NOAA/NWS National Hurricane Center, received via the National Weather Wire Service", "page": "https://hurricane.terrapin.com/text/1210985918504108034"}