000 AXPZ20 KNHC 270252 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 158 UTC Fri Sep 27 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 0240 UTC. ...SPECIAL FEATURES... Low pressure located along the monsoon trough near 17.5N111W continues to produce showers and thunderstorms. Some development of this system is possible while it moves ENE and then ESE during the next couple of days, and this system could still become a tropical depression before it becomes absorbed within a broad monsoon circulation that forms near the coast of Mexico over the weekend. This system has a medium chance of tropical cyclone formation during the next 48 hours. Please see the latest Eastern North Pacific Tropical Weather Outlook for more information. An elongated trough of low pressure near the coast of southern and southwestern Mexico is producing a large area of disorganized showers and thunderstorms. A low is expected to form along this trough during the next couple of days, and it is likely to become a tropical depression over the weekend or early next week while it moves WNW to NW at 10 to 15 mph near the southern and southwestern coasts of Mexico. Regardless of development, heavy rainfall, with the possibility of flash flooding and mudslides, is likely along the Pacific coasts of Central America and southern and SW Mexico during the next several days. This system has a medium chance of becoming a tropical cyclone during the next 48 hours and a high chance of becoming a tropical cyclone during the next 5 days. ...TROPICAL WAVES... None. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N76W to 19N104W to low pres 1006 mb near 17.5N111W to 12N133W to beyond 13N140W. Numerous moderate and scattered strong convection is seen within an area bounded by 12N87W to 11.5N91.5W to 16N94W to 12N87W. Scattered moderate and isolated strong convection is noted elsewhere N of 10N between 85W and 102W. Scattered moderate convection is occurring from 14N to 20N between 111W and 115W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Recent scatterometer data revealed light to gentle winds across the Baja California offshore waters and the entrance to the Gulf of California. Farther south, ship observations and satellite derived wind data indicated fresh offshore winds south of the monsoon trough, roughly between Acapulco and Puerto Angel. Recent altimeter data showed 7-9 ft seas within this enhanced monsoon flow near the far outer offshore waters. The low pressure system described in the Special Features section above is moving ENE through the waters south of the Revillagigedo Islands today, then will turn ESE Fri and Sat. This low will likely become absorbed within a larger monsoon circulation that will strengthen off the southern coast of Mexico this weekend. Another low is expected to develop in this region along the monsoon trough during the next couple days, and it is likely to become a tropical depression over the weekend or early next week. There is a high chance of tropical cyclone formation during the next five days. Regardless of development, heavy rainfall, with the possibility of flash flooding and mudslides, is likely along the Pacific coasts of Central America and southern and southwestern Mexico during the next several days. Elsewhere, a weakening cold front will drop southward into the northern waters this weekend, accompanied by increased NW swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh SW to W monsoon flow will support showers and thunderstorms off the coasts of Guatemala and El Salvador today through Sat, as an area of low pressure is expected to develop off the southern coast of Mexico. Offshore wave heights will build to between 7 and 11 ft by Fri, with seas to 8 ft spreading eastward towards the coastal waters of Nicaragua and northern Costa Rica tonight through the weekend. REMAINDER OF THE AREA... Light to moderate NE trade winds will persist north of 17N and west of 130W for the next couple days. Elsewhere, long period N swell is producing 7 to 9 ft seas roughly north of 27N and west of 125W, based on recent altimeter data. Wave heights will peak around 10 ft tonight and Fri. A cold front will drop southward into the northern waters and weaken this weekend. Expect moderate to fresh NE winds to develop north of 26N and west of 125W on Sun following frontal passage. $$ CAM