000 AXPZ20 KNHC 030930 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Nov 3 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 10N94W to low pressure near 16N112W 1009 mb to 13N115W to low pressure near 16N130W 1010 mb. The ITCZ continues from 16N131W to 10N140W. Scattered moderate isolated strong convection from 08N to 17N between 102W and 113W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Weak surface high centered near 27N121W will meander W of Baja California through Tue, supporting gentle to locally moderate northerly flow and 3 to 5 ft seas W of Baja. Moderate NE to E winds and 4 to 6 ft seas across Mexican offshore waters from 13N to 20N are expected to persist through early Sat. Gulf of Tehuantepec: A tightening pressure gradient will result in strong to near gale force northerly drainage flow continuing through Wed, with long range model guidance then suggesting the next gale event could begin Wed evening. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh NE drainage winds and 4 to 6 ft seas across and up to 150 nm downstream from the Gulf of Papagayo through Sat night. Model guidance is suggesting fresh drainage flow on Sun and Mon nights. Light NW-N winds and 2 to 4 ft seas are expected elsewhere N of the monsoon trough, with moderate to locally fresh southerly winds and 4 to 7 ft seas prevailing S of the trough axis. REMAINDER OF THE AREA... Surface lows along the monsoon trough are analyzed near 16N112W and 16N130W. A surface trough is also analyzed over NW waters from 30N139W to 22N141W. ASCAT data indicates winds associated with these surface features are less than 15 kt. Strong high pressure will build NW of the area through Sat night and create a cold front along the existing surface trough during this time. The newly formed front will extend from 32N130W to 22N140W late tonight, then stall from 32N124W to 21N137W by Sat night. A reinforcing surge of cold air will push southward along 32N between 135W and 140W tonight, with strong force northerly flow developing in NW waters and seas building to 8-12 ft with NW swell. Winds will diminish on Sun. Models show a frontal wave or weak low developing along the frontal boundary early Sun near 29N129W, which then drifts northward through Mon. If a deep low develops, strong N to NW winds are likely to occur NW of the low center on Sun. $$ Mundell