000 AXPZ20 KNHC 291553 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Thu Jul 29 2021 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Scattered to numerous showers and thunderstorms are evident within 120 nm south of the center of a 1007 mb low pressure area along the monsoon trough near 12N107W. So far, winds are only moderate to fresh with seas to 7 ft near this slow. However, winds and seas are expected to increase as upper- level winds become more conducive for development. There is a medium chance a tropical depression will form in the next couple of days, and a high chance of a tropical depression will form within the next five days while the system moves westward or west- northwestward at 5 to 10 kt. Another 1007 mb low pressure is centered along the monsoon trough near 14N122W. Upper level NW shear is keeping scattered to numerous showers and thunderstorms within 90 to 210 nm to the east and southeast of the low. Fresh to strong winds and seas to 8 ft are likely near this low. Environmental conditions remain conducive for continued development. There is a medium chance a tropical depression will form in the next couple of days, and a high chance of a tropical depression will form within the next five days while the system moves westward or west- northwestward at 10 kt. Please see the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details on both these systems. ...TROPICAL WAVES... A tropical wave over the far eastern part of the area has its along 81W north of 03N to across western Panama and into the southwestern Caribbean Sea. It is moving westward at 15 kt. Scattered moderate convection is from 06N to 08N east of 81W. A tropical wave with its axis along 95W extends from far southeastern Mexico and the Gulf Tehuantepec region to near 05N. It is moving westward at 10 to 15 kt. Scattered moderate to isolated strong convection is evident from 09N to 13N between 92W and 97W. A tropical wave has its axis along 109W from 03N to 15N, moving west at 10 to 15 kt. No significant convection is evident with this wave. A tropical wave has its axis near 125W/126W from 03N to 18N, moving westward at 10 kt. Scattered moderate convection is evident from 09N to 12N between 123W adn 126W. A tropical wave has axis along 139W from 03N to 16N. It is moving westward at 10-15 kt. Scattered moderate to isolated strong convection is noted from 08N to 10N between 138W and 140W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Colombia near 07N78W to across northern Panama to a 1007 mb low pressure near 12N107W to 10N114W and northwest to another 1007 mb low pressure near 14N122W and to 10N130W to beyond 10N140W. In addition to the convection described in the Tropical Waves section above, scattered moderate to isolated strong convection from 08N to 10N between 127W and 131W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong north gap winds pulsing across the Gulf of Tehuantepec, between relatively higher pressure to the north of the region and lower pressure farther south, are starting to diminish. Light to gentle variable winds are elsewhere with seas mainly to 3 to 5 ft due to a south to southwest swell. Farther north, a relatively weak pressure gradient supports gentle to locally moderate northwest winds over the Baja California offshore waters with seas in the 3 to 5 ft range in SW swell. For the forecast, high pressure north of the area and lower pressure farther south will continue to support pulses of fresh gap winds across the Gulf of Tehuantepec and off western Oaxaca tonight. Mostly moderate winds and seas will persist elsewhere. Looking ahead, seas will build off southern Mexico starting late Sat due to increased southerly swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate south to southwest winds will remain south of the monsoon trough through the forecast period along with a southwest swell that will build seas to 5-7 ft. Seas of 3-6 ft due to a southwest swell will change little over Gulf of Papagayo region during the next few days. For the forecast, fresh to strong gap winds across the Gulf of Papagayo will diminish this afternoon, then pulse again tonight into Fri, and possibly again on Sat. Elsewhere, gentle to moderate south to southwest winds will dominate the waters south of the monsoon trough through the forecast period along with southwest swell. The tropical wave along 80W may help to increase instability over most of the Central American offshore waters through the next couple of days possibly leading to enhanced convection over those offshore waters. REMAINDER OF THE AREA... See the Special Features section above for details on two low pressure systems that have potential for tropical cyclone formation. Aside from the two Special Features low pressure systems, relatively weak high pressure is present with the associated gradient allowing for generally moderate northeast trades to persist north of the monsoon trough and moderate south to southwest winds farther south, with 5 to 7 ft seas in mixed swell in most areas. Larger southerly swell is noted south of the equator. Winds and seas over some sections of the area will be impacted by the Special Features low pressure systems during the next several days. $$ Christensen/Aguirre