000 AXPZ20 KNHC 071548 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Oct 07 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 Low... A 1007 MB surface low is analyzed at 12.5N109.5W with scattered moderate isolated strong convection flaring within 180 nm over the SE quadrant of the low. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Caribbean coast of Colombia at 09N76W to across Costa Rica along 10N to the Pacific coast of Costa Rica at 11N86W, then the trough turns NW through an embedded 1009 mb surface low at 13N92W to 18N107W where the trough axis then turns SW and through a 1007 mb low pressure at 17N111W, continuing SW to 10N121W where the trough then turns W- NW to a 1010 surface low embedded in the trough at 12N137W. Scattered moderate convection is noted along the monsoon trough within 60 nm of 13N89W and continues inland across El Salvador and Honduras, but is decreasing in both coverage and intensity. Scattered moderate isolated strong convection is observed within 150 nm of the coast of Mexico from 97W to 107W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends into the area from 22N116W to 20N110W. Moderate NW winds, and 5 to 7 ft seas, in a mix of SW and NW swell, is forecast W of the Baja Peninsula today. The leading edge of a batch of long-period NW swell will arrive at 32N120W late tonight in the form of 8 to 11 ft seas. This NW swell, resulting in seas of 6 to 9 ft, will propagate S reaching along 24N on Mon night before beginning to subside, with seas of 4 to 7 ft forecast W of Baja on Tue night. Long period SW swell is maintaining seas of of 7 to 10 ft across the Mexican waters S of 16N. Expect these seas to subside to 5 to 7 ft by late Sun. Gulf of California: Fresh NW winds currently across the entire gulf waters will diminish to a moderate breeze this evening, then further diminish to light and variable winds tonight. A moderate S breeze will set up across the gulf waters N of 30N early Sun, and then increase throughout the day, with fresh to strong southerly flow forecast N of 29.5N by Sun evening ahead of a weak cold front that sweep through the waters N of 26N through Mon night. Strong NW winds will follow the front across the waters N of 30.5N on Sun night, reaching along 29.5N on Mon morning, and then quickly diminishing to a fresh NW breeze late Mon night. A moderate NW breeze is expected across the entire gulf waters by late Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate southerly winds with seas of 7 to 10 ft in long period SW swell are observed N of 07N and W of 86W. These seas are forecast to subside to 5 to 7 ft tonight. Light SW to W winds, and 5 to 7 ft seas are observed elsewhere. Expect light SW to W winds and 3 to 5 ft seas by late Sun. The southerly flow will increase to a moderate SW breeze across the waters S of 07N on Tue. REMAINDER OF THE AREA... A ridge extends into the discussion area from 32N136W to 20N110W. Moderate SW winds and 7 to 9 ft seas are noted S of the ridge from 24N to 32N W of 137W. These seas will subside to less than 8 ft today as long period NW swell propagates into the waters N of 30N between 124W and 128W. Strong N winds and 12 ft seas will reach along 32N between 120W and 128W late tonight, then diminish to a fresh breeze on Sun night. However, the NW swell in the form of 8 to 11 ft seas will propagate S across the waters N of 27N between 119W and 133W on Sun night. Fresh NE trades and 6 to 8 ft seas forecast from 09N to 15N W of 136W on Sun and Mon. Forecast 8 ft seas across the waters N of 22N between 116W and 120W on Tue morning, with these seas subsiding to less than 8 ft on Tue night. By then, another batch of long period N swell will reach along 30N to the W of 124W. Fresh to locally strong NE winds and 8 to 11 ft seas expected N of 29N W of 122W on Wed. $$ Nelson