000 AXPZ20 KNHC 291018 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0845 UTC. ...SPECIAL FEATURES... Tropical Storm Narda is centered near 16.0N 101.0W at 0900 UTC moving NW at 7 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Narda is expected to continue a NW motion during the next couple of days, bringing the center very near or across the coasts of southwestern Mexico between Michoacan and Jalisco. Narda has become better organized overnight, with large bands of thunderstorms west of the center, and some slight strengthening is forecast during the next 24 hours before potential interaction with land begins to impact the core circulation. Scattered to numerous moderate to strong convection is occurring north of 13N between 99W and 107.5W, and extends well inland across Michoacan, Colima, and Jalisco, where rainfall amounts of 3 to 5 inches can be expected before sunrise. 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 from 09.5N74W TO 07.5N81W TO 14N91W, then resumes to the W of Narda near 17N104W TO 16N117W TO 14.5N130W TO 11.5N136W TO beyond 11.5N140W. Scattered moderate isolated strong convection is noted N of 05N to the E of 80W, and N of 08N between 87W and 93W. Scattered moderate to strong convection is N of 12N between 93W and 99W, and from 08.5N to 14.5N between 127W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate NW winds prevail 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 entering the far north-central waters this morning followed by moderate NW swell raising seas to 8 ft. A ridge will build into the region later today 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 Tropical Storm Narda. A broad zone of strong to near gale force SW winds prevail south of Narda and the monsoon trough, over the southern Mexico offshore waters between Puerto Angel and Narda, and extends further SW into the tropics to near 11N107W. Recent altimeter data showed seas of 9 to 16 ft within this enhanced SW wind flow. Numerous showers and thunderstorms with strong gusty winds will continue off the southwestern coast of Mexico through Sun. Clusters of moderate to strong convection continue to affect portions of coastal Mexico from Tehuantepec to Jalisco, while other strong clusters are moving NW across the Gulf of Honduras and across Chiapas and Campeche. Heavy rainfall potential will continue through this evening across the area. Please refer to statements issued by the Meteorological Service of Mexico for more info on rainfall potential. 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 coastal Nicaragua and Costa Rica. Fresh SW to W monsoonal flow will continue to support scattered showers and thunderstorms across the offshore waters from Guatemala southeastward to Panama. Seas of 8 to 10 ft continue across the waters off Guatemala and El Salvador, with 8 ft seas extending to the northern Costa Rica offshore waters, and 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 fresh NE winds to the north of a weak cold front that extends across N portions from 30N117W to 26N140W. Seas are running 7-8 ft north of this boundary. South of the front, light to gentle breezes, with 5 to 7 ft seas prevail over much of the forecast region north of the monsoon trough W of 120W. The front will sink slowly southward and dissipate through Mon, but otherwise, little change is expected through the weekend. South of the monsoon trough, moderate to locally fresh SW winds persist west of 125W with seas of 8 or 9 ft. A few small low pressure centers are expected to form along the monsoon trough over the far southwestern portion of the area, and W of 130W through Mon, and will maintain the fresh SW winds and seas around 8 ft there through at least early Tue. $$ Stripling