{"msg": "634\nAXPZ20 KNHC 181605\nTWDEP \nTropical Weather Discussion\nNWS National Hurricane Center Miami FL\n1605 UTC Fri Sep 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 1200 UTC surface analysis and satellite imagery through\n1545 UTC.\n...SPECIAL FEATURES...\nInvest EP98: A tropical wave with axis along 119W extends from \n07N to 19N. Low pressure of 1009 is along the wave axis near\n12N119W. These feature compose a broad area of low pressure \nthat is located well southwest of the southern tip of the Baja \nCalifornia Peninsula. The wave is moving westward at about 10 \nkt. Satellite imagery reveal disorganized numerous moderate to \nstrong convection from 08N to 17N between the wave and 125W.\nEnvironmental conditions appear conducive for additional \ndevelopment of this system, and a tropical depression is likely \nto form this weekend as it moves westward across the western\nportion of the eastern Pacific. The wave has a medium chance \nof tropical cyclone formation chance through 48 hours and a high\nof formation through 7 days.\nPlease refer to the latest NHC Tropical Weather Outlook at \nwebsite: www.hurricanes.gov for more details.\n...TROPICAL WAVES...\nA tropical wave, Invest EP99, has its axis extending from 16N103W \nto 06N105W. It is moving westward at around 10 to 15 kt, and \nis part of a broad area low pressure that is located about 700 \nnautical miles south-southwest of the southwestern coast of \nMexico. Satellite imagery depicts disorganized scattered \nmoderate to isolated strong convection within 180 nm east of the \nwave from 06N to 12N. Environmental conditions are conducive for \ndevelopment, and a tropical depression is likely to form late \nthis weekend or early next week while it moves gradually north- \nnorthwestward and northward off the coast of southwestern Mexico.\n...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...\nThe monsoon trough axis extends from northwest Colombia \nsouthwestward to across the border between Panama and Colombia,\nand continues to 08N78W to 10N86W to 09N91W to 08N101W to \n06N108W to 12N115W and to 13N123W. It resumes at 15N135W to \nbeyond 13N140W. Numerous strong convection is seen from 04N to \n08N between 77W-80W. Scattered moderate to isolated strong \nconvection is from 03N to 08N between 81W-92W, and within 120 nm \nsouth of the trough between 114W-119W. Scattered moderate \nconvection is from 03N to 08N between 95W-102W. \n...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...\nThe pressure gradient between a ridge over the Gulf of America \nand the eastern extension of the Pacific monsoon is supporting \nstrong to near-gale force north to northeast gap winds across \nthe Gulf of Tehuantepec. Seas with these winds are 6 to 8 ft. \nScattered to numerous showers and thunderstorms are over most of \nthe offshore waters, with numerous coverage of the activity \nconfined to the offshore waters of Jalisco and Colima. The \nnorthern portion of tropical wave extends along 104W, northward \nto near 17N. The gradient related to high pressure west of the \nBaja California offshores is supporting moderate to fresh \nnorthwest winds N of Cabo San Lazaro. Moderate or weaker winds \nare elsewhere along with moderate seas, except for slight seas in\nthe Gulf of California. \nFor the forecast, winds will continue to pulse in Tehuantepec at\nfresh to strong speeds through Sat. The environmental conditions\nof the tropical wave along 104W are conducive for development, \nand a tropical depression is likely to form late this weekend or \nearly next week while it moves gradually north-northwestward and\nnorthward off the coast of southwestern Mexico. Regardless of \ndevelopment, this system is forecast to bring fresh to strong \nwinds and moderate to rough seas to the Michoacan and Jalisco \noffshores Tue night into midweek. Otherwise, moderate to fresh\nnorthwest winds will persist along the Baja Peninsula offshores,\nreaching strong speeds at night today and Mon. \n...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, \nAND WITHIN 750 NM OF ECUADOR...\nFresh to strong northeast to east winds prevail across the Gulf \nof Papagayo extending downstream to near 90W. Moderate easterly \nwinds from this gap event are affecting the outer offshores El \nSalvador and Guatemala. Moderate or weaker winds prevail \nelsewhere, except for moderate to fresh N winds in the Gulf of \nPanama extending to about 07N. Seas across the offshores are \nmoderate in SW swell. \nFor the forecast, the pressure gradient between the ridge north \nof the area and the eastern Pacific monsoon will support pulsing \nfresh to occasionally strong easterly winds and moderate to rough\nseas across the Papagayo region into early Sat, then pulsing to \nmoderate to fresh thereafter. Moderate winds and seas will \nprevail elsewhere.\n...REMAINDER OF THE AREA...\nThe remnant 1006 mb low of former Tropical Depression Fifteen-E \nis located near 16N136W. Fresh to strong northeast to east winds\nare within 480 nm northern semicircle of the low. Seas are 7 to \n10 ft with these winds. Satellite imagery indicates numerous \nmoderate to strong convection from 15N to 19N between 131W and \n136W. Moderate to fresh northeast northeast to east winds\nare along the northern portion of the tropical wave. Invest \nEP98, along 119W. These winds extend northward to near 22N \nbetween 115W and 128W. Seas are in the range of about 6 to 9 ft \nwith these winds as suggested by recent satellite altimeter data \npasses. Elsewhere, winds are moderate or weaker and seas are \nmoderate, except rough in the vicinity of Invest EP98. \nFor the forecast, see the Special Features and the Tropical Waves\nSection. Otherwise, environmental conditions appear conducive \nfor some development of this system as it moves westward to west-\nsouthwestward, and a tropical depression could form well to the \nsouth or southeast of the Hawaiian Islands by the middle to \nlatter part of next week.\n", "title": "Eastern Pacific Tropical Weather Discussion", "id": "1211358000956440578", "issued": "2026-09-18T16:05:00Z", "wmo": "AXPZ20", "source": "NOAA/NWS National Hurricane Center, received via the National Weather Wire Service", "page": "https://hurricane.terrapin.com/text/1211358000956440578"}