000 AXPZ20 KNHC 020249 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC fri Sep 02 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 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...SPECIAL FEATURE... A trough of low pressure located several hundred miles southeast of Acapulco, Mexico and embedded within the monsoon trough is analyzed as a 1009 mb surface low near 11.1N94.3W at 0000 UTC. Currently scattered moderate convection is observed mainly south and west of the low center from 07N to 11N between 91W and 97W. Isolated moderate convection within 150 nm north semicircle of the low center. Upper-level winds are expected to become more conducive for tropical cyclone development during the next couple of days, and a tropical depression is likely to form over the weekend while the low moves west-northwestward or northwestward near the coast of Mexico. Locally heavy rain, flash floods and mud slides are likely along the southern and southwestern coast of Mexico starting Friday and continuing through the weekend. Fresh southwesterly flow is observed southwest of the low south of the monsoon trough axis from 08.5N to 11N between 96W and 109W with combined seas of 6 to 8 ft. The pressure gradient will continue to tighten and southwesterly flow south and southwest of the low center is forecast to become strong by Friday morning. Although the array of global model guidance differs slightly on track, most suggest near gale conditions could develop over the east semicircle of the low beginning late Sat night. These winds, and the resultant high seas, could reach the Pacific coast of Mexico between 96W and 101W on Sun. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N89W through an embedded 1009 mb low pressure center at 11.1N94.3W to 15N106W to a 1010 mb low pressure at 10N120W to 12N137W. Aside from the convection associated with the low at 11.1N94.3W already discussed in the Special Features section, scattered moderate convection is observed N of 05N between 78W and 89W, from 08N to 14N between 97W and 110W and from 07N to 11N between 116W and 129W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section above for discussion on a tropical low with potential of developing into a tropical depression southwest of the Gulf of Tehuantepec on Saturday. Otherwise, a sub-tropical ridge covering the forecast waters N of 17N west of 117W is maintaining gentle to moderate northwest flow with 5 to 6 ft combined seas across the northern waters generally north of 23N and w of 116W. Variable gentle wind flow is across the remainder Baja California Sur coast and Pacific coast of Mexico along with 3 to 5 ft seas. Except for the area south of the Gulf of Tehuantepec, little change is expected through Sat evening. Moderate to fresh northwest flow will develop along the Baja Peninsula late Saturday night through Sunday. A surface trough will meander over the Gulf of California supporting light and variable flow across the gulf through Mon night, except N of 30N where intermittent south to southwesterly moderate flow will continue through early Sunday morning when it increases to fresh southwesterly flow. 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 11N94W with potential of developing into a tropical depression within offshore zone PMZ027 on Saturday. Moderate to fresh southwest flow associated with the tropical low will spread across offshore zone PMZ111 starting on early morning Friday through Saturday morning. Gentle to moderate southwesterly winds expected elsewhere through Fri morning, then the gradient will relax with gentle west to northwest flow expected elsewhere north of 05N through Sunday morning. Gentle to moderate southerly flow forecast south of 05N through Monday. REMAINDER OF THE AREA... A quasi-stationary surface ridge covering the forecast waters N of 17N west of 117W support moderate to fresh NE to E winds with a maximum of 8 ft seas N of 19N W of 120W, except from 16N to 19N W of 136W where winds are from the southeast. These winds and seas due to the pressure gradient between the ridge and hurricane Lester west of the area will shift W of 140W tonight. Moderate to fresh NE to E flow will develop on Fri and continue through late Sat S of the ridge and N of the monsoon trough, with combined seas of 4 to 7 ft, with little change through the weekend. Moderate to fresh N to NE flow is forecast N of the ridge, with 5 to 7 ft combined seas through tonight, then the gradient will relax with moderate N flow expected Fri through Mon. A tropical low currently near 10N120W will remain nearly- stationary through Sat with low chances of development. Fresh S to SW flow within 270 nm SE quadrant of the low is expected through Fri morning then expanding to the SW quadrant through Saturday morning. $$ Ramos