000 AXPZ20 KNHC 300949 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Jun 30 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 0945 UTC. ...TROPICAL WAVES... A tropical wave is analyzed from 08N95W to 17N96W and is moving W at 12 kt. Currently scattered moderate isolated strong convection is observed to the S of 12N within 300 nm either side of the wave axis. Similar convection is noted to the N of 15N within 180 nm either side of the wave, and extends inland across the Isthmus of Tehuantepec. A surface low is forecast to develop along the wave axis near 11.5N103W on Sat, and move NW to near 12.5N106w on Sun. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W across the Gulf of Panama, then turns NW into the tropical wave at 10N95W. Scatterometer winds indicate that the ITCZ forms W of the tropical wave near 12N100W, and dips SW to 08N110W, then turns W to 10N130W. Scattered moderate isolated strong convection is observed along the Pacific Coast of Colombia, generally to the N of 02N and E of 80W. Similar convection is noted to the S of the ITCZ within 60 nm either side of a line from 07N113W to 11N126W, and along the ITCZ within 180 nm either side of a line from 12N128W to 08N139W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The remnants of former tropical cyclone Dora are dissipating near 21N118W. Otherwise,a NW to SE orientated ridge axis is just w of the offshore waters supporting gentle to moderate NW flow W of the Baja Peninsula, with 3 to 6 ft seas. Long period NW swell in the form of 7 to 9 ft seas, will arrive near 30N120W on Sat afternoon, persist through early Sun, and then begin to subside on Sun afternoon. Light to gentle winds, and 3 to 5 ft seas, are expected elsewhere across the open waters N of the Gulf of Tehuantepec through mid week. Gulf of Tehuantepec...Strong northerly nocturnal drainage flow is forecast to begin late Sat night, with seas building to about 7 ft. Expect these nocturnal conditions through Wed night. Gulf of California...Light to moderate southerly flow is expected across the entire gulf waters through midday on Sat. Expect fresh to locally strong southerly flow across the gulf waters N of 30N from Sat evening through sun evening, with seas building to 5 ft in the long fetch waters. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...fresh to locally strong NE-E nocturnal winds, and seas to 7 ft, are forecast through sunrise this morning. Moderate to locally fresh nocturnal NE-E winds are then forecast each night through the middle of next week, with seas building to 6 ft. Gentle to moderate southerly winds forecast elsewhere through the middle of next week. The long period cross-equatorial swell, in the form of 7 to 10 ft seas currently across the area s of 10N will subside from the N today with seas of 4-7 ft forecast across the entire area by early tonight. REMAINDER OF THE AREA... The remnants of former tropical cyclone Dora will gradually dissipate near 21N117W through early Sat. A surface low is forecast to develop along a tropical wave near 11.5N103W on Sat, and move generally westward between 11N and 12N through the middle of next week, accompanied by light cyclonic winds. Otherwise, a NW to SE orientated ridge will extend across the area. Fresh NW to N winds are expected to the N of 30N and E of 125W on Fri and Sat, with 7-9 ft seas. Moderate anticyclonic flow forecast elsewhere to the W of 120W, with 5-7 ft seas. Long period southerly swell, in the form of 7-10 ft seas, currently across the tropical waters S of 13N E of 120W, will subside from the N today through Sat, with seas below 8 ft on Sat night. $$ Nelson