000 AXPZ20 KNHC 170321 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Sep 17 2024 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...TROPICAL WAVES... The southern portion of a tropical wave is along 86W extending from Belize to western Honduras and continuing southward over the eastern Pacific to near 09N. It is moving westward at 5-10 kt. Scattered moderate convection is noted within 120 nm either side of the wave where it just crosses the monsoon trough. Otherwise, no significant convection is occurring with this wave. A tropical wave is along 105W from southwestern Mexico to near 08N, moving westward at about 10 kt. Scattered moderate convection is within 120 nm east of the wave from 09N to 10N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11.5N73.5W to 10.5N85W to 08N93W to 10.5N104W to 10.5N122W. The ITCZ extends from 10.5N122W to 08.5N137W to beyond 09N140W. Scattered moderate convection is seen from 03.5N to 09N E of 96W. Scattered moderate to strong convection is within 60 nm of the coasts from NW Nicaragua along 87W to Cabo Corrientes along 106W, from 10.5N to 12N between 96W and 105W, within 90 nm NW of a line from 15.5N112W to 10N122W, and from 06.5N to 12N between 122W and 136W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The remnants and associated moisture of former tropical cyclone Ileana has moved well inland across Sonora, Mexico this afternoon and evening, bringing scattered showers and an isolated moderate thunderstorm or two. Gentle to moderate southerly flow prevail across the central Gulf of California in its wake, with seas 3 ft or less. A narrow plume of fresh to strong SW gap winds extends northeastward across the northern Gulf from the coast along Campo Huerfanito to near La Choya. Seas there are 4 to 6 ft, while winds and seas are lower on either side. Elsewhere, light and variable winds prevail across the southern Gulf south of 25N, where seas are 2 to 3 ft. A persistent broad and weak ridge extends southeastward into the area waters tonight. The resultant pressure gradient is producing gentle to moderate NW winds prevail across the near and offshore waters of Baja California, and extend to Cabo Corrientes and the Revillagigedo Islands. Winds have increased t fresh this evening along the coast near Punta Abreojos. Seas across these area waters are generally 3 to 5 ft except to 6 ft across the waters NW of Isla Guadalupe. Generally, light and mostly westerly winds dominate the waters from Manzanillo to the Tehuantepec region where seas are 4 to 5 ft in southerly swell east of 103W, and with mixed NW and S swell west of 103W. Scattered moderate to strong thunderstorms have shifted off the coast and into the nearshore waters from Cabo Corrientes to Chiapas. For the forecast, fresh to strong SW winds will continue over portions of the northern Gulf of California through early Tue morning. A brief instance of fresh to strong N winds is expected N of 30N early Tue morning as the tail-end of a weak cold front sweeps eastward across the far northern Gulf of California. Elsewhere, broad high pressure northwest of the area support gentle to moderate northerly winds across the Baja offshore waters will increase slightly tonight through Wed morning. Winds will pulse to fresh during the afternoons and evenings off the Baja California coast through Fri. New northerly swell will move into the regional waters Tue through Wed, raising seas slightly before slowly subsiding Thu and Fri. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh NE gap winds prevail across the Papagayo region this evening, where seas are 4 to 5 ft. Elsewhere Light and variable winds prevail across the regional waters north of 09N. Seas there range 4 to 5 ft in south swell. S of 09N, gentle to moderate southwest to west winds prevail. Seas are 4 to 6 ft in south to southwest swell there, except 2 to 3 ft inside the Gulf of Panama. Very active thunderstorms along the Central America coast from Costa Rica to Panama and Colombia this afternoon has diminished considerably this evening. For the forecast, gentle to moderate southwest to west winds will continue south of the monsoon trough through Tue, then freshen modestly Wed and Fri. North of the trough, light to gentle winds are expected through Thu. The moderate to fresh gap winds across the Papagayo region will become gentle to moderate east winds on Tue before shifting SE. Moderate seas in primarily southwest swell will continue through Wed before increasing Wed night through Fri, with little change expected afterward. ...REMAINDER OF THE AREA... A 1030 mb high continues across the NE Pacific along 153W, extending a broad ridge southward into the region, dominating the area north of the ITCZ and west of about 122W. The related pressure gradient is producing generally moderate to fresh northeast trades S of about 21N and W of 124W, except W of 135W where locally strong trades are occurring due to a weak low level trough shifting westward across that area. Seas are 7 to 8 ft in NE swell are west 135W, while seas over the rest of the area are 5 to 7 ft in mixed swell. Gentle to moderate winds and seas 4 to 5 ft are noted N of 27N. Moderate to fresh S to SE winds continue south of the ITCZ W of 130W, with gentle to moderate winds elsewhere south of the monsoon trough. Seas are 5 to 7 ft south of the monsoon trough, and 4 to 7 ft east of 120W. For the forecast, the aforementioned high pressure will drift SW through the rest of the week, with the associated ridge changing little. This will result in moderate to fresh trades south of 20N and west of 130W, and seas 6 to 8 ft in NE swell through Wed morning. Winds will become moderate to locally fresh Wed through Fri. Moderate to fresh SW to W winds and mostly seas of 4 to 7 ft are expected elsewhere south of the monsoon trough through Wed night before a modest increase E of 110W Thu and Fri. $$ Stripling