414 AXPZ20 KNHC 020354 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 354 UTC Thu Aug 2 2018 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 0300 UTC. ...SPECIAL FEATURE... Tropical Storm Hector centered near 14.0N 122.2W at 02/0300 UTC or 880 nm SW of The Southern Tip Of Baja California moving W at 10 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Numerous moderate to scattered strong convection is observed within 60 nm north and 120 nm south semicircles. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP5/WTPZ35 KNHC for more details. ...TROPICAL WAVES... A tropical wave is analyzed N of 07N along 85W moving off the coast of Nicaragua and is estimated to be progressing W at 10 to 15 kt. Scattered moderate convection is currently noted within 60 nm off the coast of El Salvador. A tropical wave extends from 07N109W to 17N109W and is moving W at 10 to 15 kt. Scattered moderate isolated strong convection is noted where the tropical wave meets the monsoon trough from 10N to 15N between 107W and 113W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... Segments of the monsoon trough extend from 08N83W to 15N113W, and from 13N125W to 10N135W, losing identity near T.S. Hector between 15N113W and 13N125W. The intertropical convergence zone continues from 10N135W to beyond 09N140W. Scattered moderate convection is observed within 150 nm either side of the monsoon trough between 94W and 101W, from 10N to 15N between 107W and 113W, and from 10N to 13N between 135W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Gentle onshore flow is expected during the daylight hours becoming moderate to fresh offshore flow during the overnight hours through Sat morning. The northerly drainage flow is expected to increase to 20 to 25 kt across, and about 120 nm downstream of the gulf waters on Sat and Sun nights with model guidance suggesting near gale conditions on Mon night with seas building to 11 ft near 15N95W. Gulf of California: Gentle to moderate southerly winds are expected along 30N with light to gentle southerly flow expected elsewhere through late Sun when guidance suggests moderate to locally fresh southerly flow will develop across the entire gulf waters, with little change through early Tue. Low pressure is expected to form several hundred miles south or southwest of the Gulf of Tehuantepec late this week. Environmental conditions are expected to be conducive for gradual development of this system over the weekend, and a tropical depression could form early next week while it moves west-northwestward off the coast of Mexico. Even if this system is weaker, fresh to strong SE winds with building seas are likely in the Mexican waters offshore of the coast from Puerto Angel to Cabo Corrientes. A surface low is forecast to develop near 09N102W early Thu and move NW to near 11N102W on Fri then turn to the N and track across the far offshore waters between 100W and 110W during the upcoming weekend, and into early next week. Although track and intensity are uncertain, mariners should expect increasing southerly winds followed by strong easterly winds, and building seas. The low has a medium chance of developing into a tropical cyclone in 3 to 5 days. Otherwise, a broad N-NW to S-SE orientated trough will meander E to W across the Baja California Peninsula and the Gulf of California through the upcoming weekend. Gentle to locally moderate NW breezes are forecast W of 108W. Expect 3 to 5 ft seas throughout. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to locally strong nocturnal easterly flow is expected through the upcoming weekend and into early next. Gentle to occasionally moderate E winds are forecast elsewhere N of the monsoon trough which is meandering between 08N and 10N. Moderate to locally fresh southerly winds are forecast S of the monsoon trough through the upcoming weekend accompanied by 4 to 6 ft seas. The exception is long period southerly swell, in the form of 7 to 8 ft seas, is forecast to reach along 03S E of 93W on Thu night and Fri. REMAINDER OF THE AREA... See the special features section for information on Tropical Storm Hector, and refer to the tropical waves section for details on the tropical waves. Thunderstorms continue to develop near where the monsoon trough intersects the tropical wave along 109W. Environmental conditions appear conducive for gradual development of this system during the next several days as it moves generally westward across the tropical eastern Pacific. Otherwise, a ridge will persist N of 20N W of 120W through the upcoming weekend, supporting moderate N to NE winds and 4 to 7 ft seas. Moderate to locally fresh southerly winds are forecast elsewhere S of the monsoon trough or roughly S of 10N for the next several days. $$ Christensen