000 AXPZ20 KNHC 081545 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Oct 08 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 15N107W with scattered moderate isolated strong convection flaring away from the low center within 75 nm of 12.5N104.5W AND 15N109W. A 1010 MB surface low is analyzed at 17N115W with scattered moderate convection observed within 60 nm of 16.5N117W. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends SW off the Caribbean coast of Colombia at 09N76W to across the northern Gulf of Panama where the trough turns W and then NW through western Costa Rica, then parallels the Pacific coast of Central America and crosses the Gulf of Tehuantepec to 16N102W, then turns SW through an embedded 1010 mb low pressure system at 15N107W, then turns NW through a second 1010 mb low pressure system embedded in the monsoon trough at 17N115W. The monsoon trough then turns SW to 10N123W, then W again through two more 1010 mb surface lows at 10N134W and 10N139W. Scattered moderate isolated strong convection is observed within 30 nm either side of a line from 07.5N78W to 03N78W, and within 75 nm either side of a line from 10N123W to 08N128W. Scattered moderate convection is noted within 30 nm either side of a line from 13N90W to 16N94W. Scattered moderate isolated strong convection is observed within 90 nm either side of a line from 17.5N104.5W to 21.5N108W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends into the area along 20N to 113W. Moderate NW winds, and 5 to 7 ft seas, in a mix of SW-W and NW swell, is observed S of 30N W of the Baja Peninsula. The leading edge of a batch of long-period NW swell has arrived at 32N120W in the form of 8 to 11 ft seas. This swell is expected to propagate S resulting in 6 to 9 ft seas reaching along 24N late Mon night before beginning to subside from the N, with seas of 4 to 7 ft forecast W of Baja on Tue night into Wed. Another round of NW swell will arrive at 32N120W on Wed night. Long period SW swell is maintaining seas of 5 to 7 ft across the Mexican waters S of 16N. Expect these seas to subside to 4 to 6 ft on Mon, and 3 to 5 ft on Tue and Wed. A moderate to fresh S breeze is setting up across the Gulf of California waters N of 30N. Expect fresh to strong southerly flow N of 29.5N this evening ahead of a weak cold front that sweep through the gulf waters N of 25N through early Tue. Strong to near gale force NW winds will follow the front across the waters N of 30.5N tonight, reaching along 29.5N on Mon morning, and then quickly diminishing to a fresh NW breeze late Mon night into early Tue. 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. Strong N winds will begin across the Gulf of Tehuantepec late Tue night and continue through Thu night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light SW to W winds, and 4 to 7 ft seas are currently observed across the area. This southerly flow will increase to a moderate SW to W breeze on Mon, with little change then expected through mid week. REMAINDER OF THE AREA...A ridge extends into the discussion area from 32N136W to 20N115W. Fresh N winds, and long period NW swell resulting in seas of 7 to 11 ft, currently across the waters from 28N to 32N between 120W and 130W, will propagate S to along 22N between 116W and 132W on Tue before beginning to subside. 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 winds and 8 to 12 ft seas are expected N of a line from 32N118W to 25N140W on Thu. $$ Nelson