388 AXPZ20 KNHC 031021 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Aug 3 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 0830 UTC. ...SPECIAL FEATURE... Hurricane Hector centered near 14.0N 127.8W at 0900 UTC moving W at 10 kt. Estimated minimum central pressure is 975 mb. Maximum sustained winds are 90 kt with gusts to 110 kt. Numerous moderate to strong convection is within 90 nm of the center. Scattered moderate isolated strong convection is observed elsewhere within 120 nm of the center. Refer to the latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP5/WTPZ35 KNHC for additional details. ...TROPICAL WAVES... A tropical wave axis is N of 09N along 93W moving W at 15-20 kt. Scattered moderate isolated strong convection is noted south and west of where the wave intersects the monsoon trough between 85W and 93W. A tropical wave axis extends from 06N116W to 18N115W and moving W at 15 kt. Scattered moderate isolated strong convection is observed within 120 nm W of the wave axis from 13N to 16N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W from the coast of Costa Rica near 09N84W to 15N121W, where the trough loses identity within the larger cyclonic circulation associated with Hurricane Hector. Scattered moderate isolated strong convection is observed within 45 nm N and 180 nm S of the trough axis between 85W and 120W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Gentle onshore flow is expected during the daylight hours and moderate to fresh offshore flow is forecast during the overnight hours, with little change through Sat. The northerly drainage flow is expected to increase to 20 kt across, and about 120 nm downstream, of the gulf on Sat and Sun nights. Model guidance suggests a slightly stronger event on Mon night, when seas will build to 10 ft near 15N95W. Gulf of California: Gentle to moderate southerly winds are expected along 30N while light to gentle southerly flow is expected elsewhere through early Sun. Model guidance suggests moderate southerly flow will develop across the entire gulf waters Sun, with little change afterwards through early Tue. A surface low is forecast to develop near 13N103W this weekend then move NW across far offshore waters between 100W and 117W through the middle of next week. Although its actual track and intensity are uncertain, mariners can expect increased southerly winds followed by strong to near gale force easterly winds, and building seas. The low has a high chance of developing into a tropical cyclone in the 3-5 day time frame. Otherwise, a broad N-NW to S-SE orientated trough will meander W of the Baja Peninsula and the Gulf of California through the middle of next week. Gentle to locally moderate NW breezes and 3 to 5 ft seas are expected until the developing tropical low reaches the area. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to fresh nocturnal easterly flow is expected into early next. Gentle to occasionally moderate E winds are forecast elsewhere N of the monsoon trough, which will meander between 09N and 11N. Moderate to locally fresh southerly winds are forecast S of the monsoon trough this weekend, accompanied by 4 to 6 ft seas. REMAINDER OF THE AREA... See the special features section for information on Hurricane Hector, and refer to the tropical waves section for details on the tropical waves. A surface low is forecast to develop near 12N100W on Sat and move NW to an estimated position near 13N105W Sun night and near 15N108W on Tue. This low has a high chance of developing into a tropical cyclone in 3-5 days. Otherwise, a ridge will meander from 32N135W to 19N110W through the weekend, supporting moderate N to NE winds and 4-7 ft seas. Moderate to locally fresh southerly winds are forecast elsewhere S of 10N for the next several days. $$ Mundell