000 AXPZ20 KNHC 030928 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Sep 03 2016 Tropical weather discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0845 UTC. ...SPECIAL FEATURE... A broad area of low pressure embedded within the monsoon trough several hundred miles southeast of Acapulco, Mexico is centered near 15N99W with an estimated pressure of 1007 mb at 0600 UTC. Convection associated with the system remains disorganized and is embedded within the monsoon trough. However, atmospheric conditions are expected to become more conducive for development. The disturbance should gradually consolidate during the next couple of days, with a tropical depression likely to form this weekend while it moves west-northwestward near the coast of Mexico. Fresh to locally strong southwesterly flow is currently observed S of the low, with combined seas of 6 to 8 ft in southwest swell. The pressure gradient between high pressure along Mexico and the low will continue to increase as the system tracks NW. This will result in fresh to near gale-force winds expanding up to 120 nm over the NW semicircle and 240 nm over the SE semicircle of the low during the weekend. Due to the close proximity to the Pacific coast of Mexico, these winds, and the resultant high seas and surf, could reach the Pacific coast of Mexico between 95W and 106W over the next 48 to 72 hours. These strong, or higher winds, will shift northward along the Mexican coast through early next week, and likely spread into the southern Gulf of California on Tue. Locally heavy rain, flash floods, and mud slides are likely along the southern and southwestern coasts of Mexico through the weekend. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends W from the Pacific coast of Costa Rica at 10N85W, through an embedded 1007 mb low pressure center at 15N99W, then continues to 13N117W...then turns to a 1010 mb low pressure at 12N120W, and then continue W to 09N140W. Scattered moderate convection is from 10N TO 13N between 103Wand 112W. Scattered moderate convection is from 08N TO 12N between 119W and 134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section above for the discussion on a tropical low with high chances of developing into a tropical depression S or SW of the Gulf of Tehuantepec this weekend. The tropical system is forecast to track NW through the offshore waters through the middle of next week. Otherwise, a sub-tropical ridge extending SE just to the W of the offshore waters, will maintain gentle to moderate NW flow, with 5 to 6 ft combined seas, across the waters along the Pacific coast of Baja through Sun, with fresh NW flow expected to develop within 120 nm of Baja Peninsula early Mon morning through Tue morning. A surface trough will meander over the Baja Peninsula, and across the northern Gulf of California supporting light and variable flow across the Gulf of California through Mon, except increasing to moderate to fresh southerly flow between 30N and 31N early Sat morning, and fresh to locally strong southerly flow is expected in the same area on Sat night. As mentioned, winds and seas conditions are anticipated to deteriorate across the southern Gulf of California beginning on Mon night, and then spread n across the entire gulf waters by the middle of next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... See special features section above for discussion on a tropical low near 15N99W with fresh to locally strong SW flow extending across the western waters of offshore zone PMZ111. These wind and seas conditions will move west of the area early Saturday morning. Gentle westerly winds and 3 to 5 ft seas expected elsewhere N of 05N, and moderate to locally fresh southerly flow and 3 to 5 ft seas forecast S of 05N through the period. REMAINDER OF THE AREA... Moderate to fresh NE to E flow will continue through late Sat S of the quasi-stationary sub-tropical ridge and N of the monsoon trough, with combined seas of 4 to 7 ft. The gradient should relax some late in the weekend. A weak tropical low currently near 12N120W will move slightly NE within the next 24 hours and gradually dissipate in the monsoon Sun. Fresh to locally strong SW flow currently observed within 90 nm S of a line from 13N118W to 08N130W is forecast to diminish to 15 to 20 kt on Sun. $$ Formosa