000 AXPZ20 KNHC 281520 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1520 UTC Sat Sep 28 2019 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Potential Tropical Cyclone Sixteen-E is centered near 14.9N 100.4W at 28/1500 UTC moving NW at 11 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. A northwestward motion is expected to continue during the next couple of days. This track should bring the disturbance or the cyclone very near or over the southwestern coast of Mexico. Some strengthening is forecast during the next 48 hours, and the disturbance is expected to become a tropical storm later today or Sunday. However, if the center forms closer to the coast and interacts with the high terrain of Mexico, weakening should then occur. The disturbance is becoming better organized, and a tropical depression or a tropical storm is forecast to form later today or Sunday. The disturbance is expected to produce total rain accumulations of 3 to 7 inches with isolated maximum amounts of 15 inches along the southwestern coast of Mexico from Chiapas to Nayarit through Monday. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N76W to 10N82W to 15N90W to 14.5N100W to 15N125W to 12N140W. Numerous moderate scattered strong convection is noted from 17N to 23N between 105W and 107W. Scattered strong convection is occurring within 120 nm of the monsoon trough between 93W and 107W. Scattered moderate isolated strong convection is noted from 03N to 07N east of 80W, and within 180 nm south of the monsoon trough west of 122W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Overnight scatterometer data revealed moderate NW winds across the Baja California Norte offshore waters, while fresh NW winds were noted south of Cabo San Lazaro to Cabo San Lucas. A strong line of thunderstorms extends from east of Las Tres Marias southward across Cabo Corrientes and into the adjacent offshore waters. These storms are likely producing strong wind gusts and locally rough seas. Otherwise, seas are running 5-7 ft across the Baja offshore waters in mixed NW and SW swell, except to 8 ft within the fresh flow between Cabo San Lucas and the Revillagigedo Islands. A weakening cold front offshore of southern California will dissipate today. A high pressure ridge will build into the region Sun through early next week and freshen NW winds over the Baja California Norte waters. Please see the Special Features section above for information about Potential Tropical Cyclone Sixteen-E. Strong W to SW winds prevail south of the monsoon trough over the southern Mexico offshore waters. Overnight altimeter data showed 8-13 ft seas within this enhanced flow over the waters between Acapulco and Puerto Angel, and offshore seas likely peak around 15 ft this morning. Numerous showers and thunderstorms with strong gusty winds will continue off the southwestern coast of Mexico through Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh SW to W monsoon flow will support scattered showers and thunderstorms across the offshore waters from Guatemala southward to Costa Rica today. Overnight altimeter data indicated 8-10 ft seas across the waters off Guatemala and El Salvador, with 8 ft seas extending to the northern Costa Rica offshore waters. Seas 8-12 ft will persist off Guatemala and El Salvador into tonight, then remain 8 ft or greater through Mon before subsiding Mon night. REMAINDER OF THE AREA... Overnight satellite wind data showed a small area of moderate to fresh NE winds roughly north of 26N and west of 135W. Seas in this region are running 8-10 ft in combined northerly swell and locally generated wind waves. Seas will gradually subside to 8 ft in this area on Sun. Elsewhere, high pressure centered near 24N127W is supporting light to gentle breezes with 5-7 ft seas over much of the high seas north of the monsoon trough. Little change is expected through the weekend. South of the monsoon trough, moderate to locally fresh SW winds persist west of 125W. An area of low pressure is expected to form along the monsoon trough over the southwestern portion of the high seas early next week. This could result in fresh to strong winds with locally higher seas near the low center. $$ Reinhart