994 AXPZ20 KNHC 021001 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 830 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURE... Tropical Storm Hector centered near 14.3N 123.4W at 02/0900 UTC or 930 nm WSW of The Southern Tip Of Baja California moving WNW at 10 kt. Estimated minimum central pressure is 995 mb. Maximum sustained wind speed is 60 kt with gusts to 70 kt. Northeasterly shear is impacting the storm currently. Numerous moderate to scattered strong convection is noted within 45 nm in the northeast and 150 nm in the southwest semicircles of Hector. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP5/WTPZ35 KNHC for more details. ...TROPICAL WAVES... A tropical wave is analyzed N of 10N along 88W through the Gulf of Fonseca and eastern El Salvador. The tropical wave is estimated to be moving westward at 10 to 15 kt. No significant convection is noted along the tropical wave axis, but there may be some enhancement of a large area of overnight showers and thunderstorms along the coast from Guatemala to Oaxaca. Another tropical wave is analyzed from 07N to 17N along 111W, moving W at 10 to 15 kt. While mostly a lower to mid level feature, a scatterometer pass from 04 UTC hinted is defined at the surface as well. Scattered moderate convection is observed from 14N to 17N between 110W and 113W. Scattered moderate convection is also evident where the tropical wave is interacting with the monsoon trough, from 12N to 14N between 112W and 117W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Nicarauga near 12N87W to 14N118W. West of that, it loses identity around T.S. Hector, the resumes from 12N127W to beyond 10N140W. Scattered moderate to isolated strong convection is noted within 90 nm north of the trough axis between 90W and 93W. Scattered moderate convection is active from 06N to 09N between 95W and 105W, within 90 nm south of the monsoon trough between 112W and 117W. ...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 10 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. Looking ahead, an area of low pressure may form over the eastern Pacific through the next several days and move through Revillagigedo Islands and into the water beyond 90 nm off Baja California Sur by mid week possibly as a tropical depression. 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. 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. Low pressure is expected to form near the tropical wave currently along 111W. Environmental conditions appear conducive for gradual development of this system during the next few days as it moves generally westward across the tropical eastern Pacific. By early next week, close proximity to another developing low pressure system to the east could limit the potential for further development of this disturbance. The other low pressure area is forecast to form several hundred miles south or southwest of the southern coast of Mexico 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. 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