000 AXPZ20 KNHC 091548 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Oct 09 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 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...Tropical Lows... A 1010 MB surface low is analyzed at 15.5N106W with scattered moderate isolated strong convection observed within 90 nm over the N quadrant of the low. This low is forecast to drift SE through tonight. A 1010 MB surface low is quasi-stationary at 16N116W with scattered moderate isolated strong convection observed within 120 nm over the W quadrant of the low. This low is forecast to fill tonight. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends NW off the Caribbean coast of Colombia at 09N78W, and extends across the Gulf of Panama and across the far SW Caribbean, then returns inland Costa Rica and Nicaragua before moving offshore and continues NW paralleling the Pacific coast of Guatemala to the Gulf of Tehuantepec, then turns SW through an embedded 1010 mb low pressure system at 15.5N106W, then turns W-NW through a second 1010 mb low pressure system embedded in the monsoon trough at 16N116W. The monsoon trough then turns SW to 09N130W, then W again to beyond 10N140W. Scattered moderate to strong convection is observed along the Pacific coast of Colombia and extends W to along 79.5W. Isolated moderate to strong convection is observed along the monsoon trough within 120 nm either side of a line from 08N81W to 13N91W to 12N101W. Scattered moderate isolated strong convection is noted along the monsoon trough within 45 nm either side of a line from 12N125W to 08N130W to 09N138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends into the area along 21N to to the E of 113W. Light W to NW winds, and 6 to 9 ft seas, primarily in NW swell is observed N of 27N W of the Baja Peninsula. This swell is expected to propagate S resulting in 6 to 9 ft seas reaching along 24N tonight before beginning to subside from the N, with seas of 3 to 6 ft forecast W of Baja on Tue night into Wed. Another round of NW swell will arrive at 32N120W on Wed night and reach as far S as 26.5N on Fri. Strong to near gale force N winds will begin across the Gulf of Tehuantepec on Tue night and continue well into the upcoming weekend. Expect seas to build to 9 ft downstream of the gulf waters near 15N95W. Long period NW swell supporting seas of 5 to 7 ft observed elsewhere across the Mexican waters are expected to gradually subside with 3 to 5 ft by mid week. Strong to near gale force NW winds are expected today through late tonight across the Gulf of California to the N of 29.5N W of 113W. A moderate NW breeze is expected across the entire gulf waters late Tue into Tue night when the pressure gradient will abruptly relax resulting in light and variable winds throughout the gulf waters on Wed and Thu except becoming a moderate southerly breeze over the northern waters on Thu. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds with 3 to 5 ft seas are expected to the N of 08N Light SW to W winds, and 4 to 7 ft seas are currently observed across the area S of 08N, but expected to soon increase to a moderate SW to W breeze, with little change then expected through the remainder of the week. REMAINDER OF THE AREA...A ridge extends into the discussion area from 32N136W to 21N115W. Fresh N winds, and long period NW swell resulting in seas of 8 to 12 ft, currently across the waters from 27N to 32N between 120W and 135W, will gradually subside as the southern edge of 8 ft seas reaches along 22N between 120W and 128W on Tue, with these subsiding to less than 8 ft on Tue night. Another batch of fresh to locally strong N winds, and long period N swell, will reach along 30N to the W of 124W on Tue night. Fresh to locally strong NE-E winds and 8 to 12 ft seas are expected N of a line from 32N118W to 27N118W to 14N140W on Fri. $$ Nelson