000 AXPZ20 KNHC 182103 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1943 UTC Fri Aug 18 2017 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURE... Tropical Depression Thirteen-E is centered near 14.8N 117.9W at 18/2100 UTC, moving west, or 280 degrees, at 13 kt. Minimum central pressure is estimated at 1006 mb. Maximum sustained winds are 30 kt with gusts to 40 kt. Scattered strong convection is currently observed in bands within 210 nm W, and 180 nm E semicircles of the center. The system is expected to reach tropical storm intensity tonight, and then reach minimal hurricane intensity Sun. Refer to National Hurricane Center Forecast Advisory under WMO/AWIPS headers WTPZ23 KNHC/MIATCMEP3, and the High Seas Forecast under WMO/AWIPS headers FZPN03 KNHC/MIAHSFEP2 for additional information. ..TROPICAL WAVES... The axis of a tropical wave is near 98W north of 07N, moving W at 15- 20 kt. Scattered moderate isolated strong convection is observed from 06N to 09N between 91W and 100W. The axis of a tropical wave is near 111W from 10N to 22N, moving W at 15 kt. Scattered moderate convection is noted from 20N to 22N between 109W and 111W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N76W to 08N98W to 10N110W where it loses identity. The monsoon trough resumes SW of TD Thirteen-E and extends to 12N124W to 13N130W to 12N136W to 13N140W. Scattered moderate isolated strong convection is noted north of 04N and east of 82W. Scattered moderate convection is noted from 08N to 10N between 110W and 113W. Scattered moderate convection is noted within 180 nm south of the monsoon trough west of 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A NW to SE orientated low level trough will prevail across the Baja California Peninsula and Gulf of California through Mon night. A ridge prevails west of the Baja California peninsula. This synoptic setup will produce a moderate NW breeze through the weekend to the W of the Baja California Peninsula, except the pressure gradient will tighten each evening with fresh NW flow within 90 nm of the Baja coast with 3 to 6 ft seas. Gulf of California...light to gentle southerly flow will persist across the Gulf of California through the upcoming weekend, except a moderate to locally fresh breeze will prevail over the waters N of 29.5N. Gulf of Tehuantepec: fresh to locally brief and strong N drainage winds are expected during the overnight hours with seas building to 8 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: moderate nocturnal drainage flow is expected through the weekend. Otherwise, light and variable to gentle NE to E flow expected N of the monsoon trough through early Mon, while moderate to locally fresh southerly winds are expected S of the monsoon trough with 3 to 6 ft seas throughout. REMAINDER OF THE AREA... High pressure ridge extends across the northern waters. Outside the influence of TD Thirteen-E, moderate to locally fresh anticyclonic flow is forecast N of the monsoon trough and W of 120W. $$ AL