000 AXPZ20 KNHC 290248 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 108 UTC Sun Sep 29 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 0000 UTC surface analysis and satellite imagery through 0215 UTC. ...SPECIAL FEATURES... Tropical Storm Narda is centered near 15.4N 100.6W at 29/0300 UTC moving NW at 8 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Narda is moving toward the northwest and this motion is expected to continue during the next couple of days, bringing Narda very near or over the southwestern coast of Mexico. Some slight strengthening is forecast during the next 48 hours. However, if the center moves closer to the coast and interacts with the high terrain of Mexico, weakening could occur. Narda is expected to produce total rain accumulations of 5 to 10 inches, with isolated maximum amounts of 15 inches along the southwestern coast of Mexico from Oaxaca to Nayarit through Monday. This rainfall will cause life-threatening flash floods and mudslides, especially in mountainous terrain. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends along northern Central America and enters the eastern Pacific Ocean through the Gulf of Tehuantepec near 15N93W, then continues to 15N100W to 13N115W to 14N125W to 12N140W. Scattered moderate isolated strong convection is noted N of 13N between 92W and 103W, including the Gulf of Tehuantepec. Similar convection is within 90 nm N of the trough between 103W and 106W, and from 09N to 14N W of 129W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Scatterometer data revealed gentle to moderate NW winds across the Baja California Norte offshore waters, while moderate to fresh NW winds were noted south of Cabo San Lazaro to Cabo San Lucas. Seas are running 5 to 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 is reaching the far north-central waters tonight followed by NW swell. A ridge will build into the region Sun through early next week and freshen NW winds over the Baja California waters, particularly N of Cabo San Lazaro. Please see the Special Features section above for information about Potential Tropical Cyclone Sixteen-E. Strong SW to W winds prevail south of the monsoon trough over the southern Mexico offshore waters. Altimeter data showed 8-13 ft seas within this enhanced flow over the waters between Acapulco and Puerto Angel. Numerous showers and thunderstorms with strong gusty winds will continue off the southwestern coast of Mexico through Sun. Clusters of moderate to strong convection are currently affecting parts of the States of Chiapas, Oaxaca and southern Veracruz. The Mexican Weather Service reported this morning rainfall amounts between 3 and 5 inches from Chiapas to Guerrero. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough extends across the SW Caribbean Sea and northern Central America. Fresh SW to W monsoonal flow will continue to support scattered showers and thunderstorms across the offshore waters from Guatemala southward to Panama. Altimeter data indicated 8 to 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... Elsewhere, high pressure located well NW of the forecast area is supporting light to gentle breezes, with 5 to 7 ft seas over much of the forecast region north of the monsoon trough W of 120W. Little change is expected through the weekend. South of the monsoon trough, moderate to locally fresh SW winds persist west of 125W with building seas to 8 or 9 ft. An area of low pressure is expected to form over the far southwestern portion of the eastern North Pacific early next week. Some gradual development is possible thereafter while the system drifts slowly eastward or northeastward. Currently, the Tropical Weather Outlook gives this system a low chance of tropical cyclone formation through 5 days. $$ GR