000 AXPZ20 KNHC 311629 AAA TWDEP Tropical Weather Discussion...Updated NWS National Hurricane Center Miami FL 1511 UTC Sun Jul 31 2016 Updated Special Features for Tropical Depression Nine-E 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 1630 UTC. ...SPECIAL FEATURES... Tropical Depression Nine-E centered near 14.2N 120.5W AT 31/1630 UTC or 795 nm southwest of the southern tip of Baja California moving west-northwest at 8 kt. Estimated minimum central pressure 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 35 kt. Scattered moderate and isolated strong convection is within 210 nm in the southeast and 120 nm in the northwest semicircles of the depression. Associated seas are 8 to 11 ft. The depression is forecast to continue to move west- northwest today while strengthening to a tropical storm by this evening, and then more northwesterly. The system is forecast to move west of 140W by early Thursday while weakening and becoming a post-tropical/remnant low. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for more details. ...TROPICAL WAVES... A tropical wave along 106W northward of 05N is moving west at 10 to 15 kt. Scattered moderate convection is from 09N to 17N between 97W and 103W, and also from 10N to 14N between 93W and 97W. Model guidance continues to indicate the potential for broad low pressure to form along the wave axis in the next few days. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N80W to 08N93W to 10N106W to low pressure near 14.5N120W to 10N140W. Scattered moderate convection is from 06N to 10N between 109W and 114W, and also within 150 nm to the south of the axis between 123W and 138W. Also, scattered moderate convection is from 21N to 23.5N within 120 nm west of the coast of Mexico. This convection developed overnight across Jalisco and Nayarit before propagating offshore. ...DISCUSSION... N of 15N E of 120W: In the Gulf of California, weak surface troughing will linger along the Baja California peninsula for the next several days. Light to moderate southerly flow will prevail across the northern Gulf, with northerly flow across the southern Gulf. Across the Gulf of Tehuantepec, nocturnal northerly flow will pulse to fresh to strong during the overnight and early morning hours starting late tonight, and occurring each night through Thursday morning. Seas will build to up to 8 to 10 ft by early Monday. Elsewhere, a weak surface ridge extends into the area from the northwest. This ridging will support mainly gentle west to northwest flow across the open Pacific waters, occasionally pulsing to moderate just offshore of the Baja California peninsula. Seas will remain in the 4 to 6 ft range. S of 15N E of 120W: Across the Gulf of Papagayo, fresh easterly drainage flow is expected through Monday during the overnight hours helping to build fresh seas to 7 to 9 ft. Weaker winds are expected through the rest of the next week as the monsoon trough drifts slightly northward. Otherwise, light to moderate flow is anticipated on either side of the monsoon trough. Long-period, cross-equatorial southwesterly swell producing seas of 4 to 7 ft will linger through most of the week. W of 120W: Ridging extending from northwest of the area is disrupted by the remnant 1014 mb circulation of Frank, currently near 22N133W. This low remnant will become a trough later today or tonight. Fresh to strong northerly winds offshore of California will generate fresh northerly swells. Seas of 8 ft will propagate down to 29N by late tonight into early Monday, decaying to less than 8 ft by the middle of the week. $$ LEWITSKY