{"msg": "552\nAXPZ20 KNHC 200256\nTWDEP \nTropical Weather Discussion\nNWS National Hurricane Center Miami FL\n0405 UTC Thu Aug 20 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\n0130 UTC.\n...SPECIAL FEATURES...\nCentral Pacific (EP90): A broad area of low pressure, Invest,\nEP90, is located well to the east-southeast of the Hawaiian \nIslands near 10.5N140W. Associated winds are currently 20 to 30\nkt and seas are 8 to 10 ft. This low is along a tropical wave at\n140W. The system is producing showers and thunderstorms that are\ngradually becoming better organized. Scattered to numerous\nmoderate to strong convection is noted from 03N to 16N between\n131W and 140W. Environmental conditions appear favorable for \nfurther development of this system, and a tropical depression is \nlikely to form during the next day or so while the disturbance \nmoves westward to west-northwestward at 10 to 15 mph and crosses \ninto the Central Pacific tonight. Interests in the Hawaiian \nIslands should closely monitor the progress of this system. This \nsystem has a high chance of tropical cyclone formation in the \nnext 48 hours. Interests in the Hawaiian Islands should closely \nmonitor the progress of this system. Please refer to the latest \nNHC Tropical Weather Outlook at website:\nhttps://www.nhc.noaa.gov/text/MIATWOEP.shtml for more details.\n...TROPICAL WAVES...\nThe axis of a tropical wave is near 95.5W from 02N to 16N near\nthe western Gulf of Tehuantepec, moving westward at 15 to 20 kt.\nScattered to numerous moderate to strong convection is noted from\n09N to 13N between 92W and 99W.\nThe axis of a tropical wave is near 109W south of 17N, moving \nwestward at 10 kt. Scattered moderate isolated strong convection \nis noted from 07N to 15N between 101W and 113W. An area of low\npressure is expected to form several hundred nautical miles \nsouth-southwest of the coast of southern Mexico around the end \nof the week. Gradual development of this system is likely \nthereafter, and a tropical depression is likely to form this \nweekend while the system moves generally west-northwestward, \nremaining well offshore of Mexico. This system has a low chance\nof tropical cyclone formation in the next 48 hours, and a high\nchance in the next 7 days. Regardless of development, expect\nincreasing winds and seas to impact the outer offshore waters of\nsouthwestern Mexico. Please refer to the latest NHC Tropical \nWeather Outlook at website:\nhttps://www.nhc.noaa.gov/text/MIATWOEP.shtml for more details.\nThe axis of a tropical wave is near 140W, and is described above\nin the Special Features section above regarding the possibility\nof tropical cyclone formation.\n...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...\nThe monsoon trough extends from 1007 mb low pressure over\nnorthern Colombia at 10N74W to 08N91W to 1006 mb low pressure \nnear 09N110W to 06N122W to low pressure, Invest EP90, near\n10.5N140W. Other than the convection described above with three\ntropical waves, scattered moderate isolated strong convection is\nnoted from 03N to 08N between 77W and 94W, from 10N to 17N \nbetween 99W and 107W, from 03N to 07N between 113W and 132W, and \nfrom 07N to 14N between 122W and 131W.\n...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...\nPlease refer to the Tropical Waves section above for information\non a tropical wave that has a potential for tropical development\noffshore Mexico this upcoming weekend, and for related\nconvection. \nHigh pressure across the NE Pacific extends a ridge south-\nsoutheastward into the regional waters to just northwest of the\nRevillagigedo Islands. The pressure gradient over the waters from\nsouthwestern Mexico to Baja California has weakened today,\nallowing for moderate or weaker winds across those waters,\nincluding in the Gulf of California, except lingering fresh winds\nin the northern Gulf. Meanwhile, a tight pressure gradient \ncontinues over the Gulf of Tehuantepec where the northern portion\nof a tropical wave is moving by, and is producing strong N to NE\ngap winds in the Gulf. Resultant seas of 5 to 7 ft are present \nthere. Seas are 4 to 6 ft across the remainder of these offshore \nwaters, and 1 to 3 ft inside the Gulf of California.\nFor the forecast, northerly gap winds will continue to pulse to \nstrong north winds over the Gulf of Tehuantepec each evening and \nnight through the next several days, with seas occasionally\nbuilding to rough. Low pressure across Baja California will \nsustain a southerly wind flow across the Gulf of California \nwaters, with fresh winds expected across northern portions there \ngradually diminishing later tonight. Winds may freshen across the\nGulf of California Sat night through Sun night. Looking ahead, \nwinds and seas are expected to build across the outer offshore \nwaters of southwestern Mexico by Fri into the upcoming weekend in\nassociation with a developing area of low pressure, expected to \ndevelop outside of the offshore waters.\n...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, \nAND WITHIN 750 NM OF ECUADOR...\nRefer to the Tropical Waves section above for details on any\nconvection.\nFresh to locally strong easterly gap winds continue across the \nPapagayo region. Seas there are 5 to 8 ft with these winds, with\nthe highest seas extending well downwind to near 11N92W where\nmoderate to fresh winds also extend to. Winds are moderate or \nweaker elsewhere north of the monsoon trough, and moderate south \nof the monsoon trough, except moderate to fresh south of the\nEquator, highest near the entrance of the Gulf of Guayaquil where\nthey are locally strong2. Seas across most of the remainder of \nthe waters north of the Equator are 4 to 6 ft in mixed cross \nequatorial S and SW swell, and 7 to 9 ft in S to SW swell south \nof 02N, highest south through southwest of the Galapagos \nIslands.\nFor the forecast, the pressure gradient between high pressure \nover the northwestern Caribbean and relatively lower pressure \nover Central America will lead to fresh NE to E gap winds pulsing\nto strong winds over the Papagayo region each evening and night \nthrough the early next week, resulting in rough seas at times. \nModerate to fresh winds extending well downwind of Papagayo will \nimpact the outer waters offshore of El Salvador and Guatemala \nthrough at least early next week. Moderate to locally fresh \nsoutherly winds south of the monsoon trough and across the \nGalapagos waters will gradually diminish tonight through Thu, \nthen remain gentle to moderate through the weekend. Cross- \nequatorial SW swell moving into the regional waters will continue\nto merge with larger S to SE swell dominating the southern \nPacific waters well south of the Galapagos to produce rough seas \n8 ft and greater south of 02N, and moderate seas elsewhere \nthrough Thu before seas subside. \n...REMAINDER OF THE AREA...\nPlease see the Special Features section and the Tropical Waves \nsection above for information on two systems that have the\npotential for tropical cyclone formation, and any associated\nconvection currently present leading to locally higher winds and\nseas.\nHigh pressure across the NE Pacific extends a ridge south- \nsoutheastward into the regional waters to just northwest of the \nRevillagigedo Islands, however it is now disrupted by a surface \ntrough analyzed from 30N135W to 23N140W. Away from Invest EP90\nalong 140W and exiting into the Central Pacific basin, moderate \nto fresh winds are near a 1006 mb low pressure at 09N110W along a\ntropical wave at 110W, from 10N to 14N between 108W and 112W \nwhere seas are locally rough. Moderate to fresh NE to E winds \nextend well downwind from a Gulf of Papagayo gap wind event to \nnear 10N100W. Seas are locally rough there as well. Winds are \nmoderate or weaker across the remainder of the waters, except \nmoderate to fresh south of 06N. Seas are 8 to 10 ft near Invest \nEP90, and 4 to 6 ft elsewhere north of 12N, 6 to 8 ft from 07N to\n12N, and 7 to 9 ft in mixed SE and SW swell south of 07N.\nFor the forecast, regardless of tropical development, the \nfeatures described above will bring some increasing winds and \nseas to area waters south of 20N, as they move south of the \ncurrent ridge in place. Invest EP90 near 140W will move away from\nthe waters into the Central Pacific basin through Thu. Away from\nthese features, little change is expected in marine weather \nthrough the next several days, except for the rough seas over the\nsouthern waters which are forecast to subside by the start of the\nweekend.\n", "title": "Eastern Pacific Tropical Weather Discussion", "id": "1202992501247082499", "issued": "2026-08-20T04:05:00Z", "wmo": "AXPZ20", "source": "NOAA/NWS National Hurricane Center, received via the National Weather Wire Service", "page": "https://hurricane.terrapin.com/text/1202992501247082499"}