000 AXPZ20 KNHC 081007 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Oct 8 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 0830 UTC. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from NW Colombia near 10.5N74W TO 09N79.5W TO 17N100W TO low pres 1010 MB near 14.5N107.5W TO low pres 1010 MB near 16.5N115.5W TO 10N126W TO low pres 1010 MB near 10.5N133W TO low pres 1010 MB near 11N138.5W TO 11N140W. Scattered moderate isolated strong convection is currently within 120 nm N and 150 nm S of the monsoon trough between 100W and 110W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends SE from strong high pressure across the NE Pacific through 30N136W to SW of Cabo San Lucas near 21N116W. The pressure gradient offshore of Baja California remains modest tonight and is producing moderate NW winds and 5 to 7 ft seas, in a mix of SW and NW swell. Little change in these conditions are expected today. However, the leading edge of a new pulse of long-period NW swell will arrive across the N waters late tonight and raise seas to 8 to 11 ft seas across the far NW waters by Mon morning. This NW swell will propagate S with seas reaching 8 ft and higher near 24N by Mon night before beginning to subside. Seas of 6 to 8 ft are then forecast W of Baja by Tue night. Long period SW swell are maintaining seas of 7 to 9 ft across the Mexican waters S of 18N. Expect these seas to subside to between 5 and 7 ft by late Sun. Moderate NW winds covering the entire basin will continue to diminish to light and variable by dawn this morning. A moderate SE to S breeze will then set up over the waters N of 29N during the morning hours, and steadily increase. Fresh to strong southerly flow is forecast N of 29.5N by Sun evening ahead of a weak cold front sweeping through the waters N of 26N on Mon night. Strong NW winds will follow the front across the waters N of 30.5N Sun night, reaching as far south as 29N on Mon morning. Seas in this area are expected to peak around 8 ft. Winds will quickly diminish to a fresh NW breeze late Mon night. A light to moderate NW breeze is expected across the entire gulf waters by late Tue. A low level trough has developed in the past 24 hours along the Mexican coast from southern Sonora southward to northern Sinaloa to near Las Tres Marias. Ample tropical moisture continues along and just E of this trough and spawned scattered clusters of moderate to strong convection late Saturday afternoon through the early morning hours, where strong convection lingers across Las Tres Marias. Global models show this trough persisting through tonight before weakening, and thus active convection is expected in this area again this afternoon through tonight. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate southerly winds and seas of 7 to 9 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 by Sunday evening. Light SW to W winds and 5 to 7 ft seas elsewhere will become light SW to W winds and 3 to 5 ft seas respectively by late Sun. The southerly flow will increase to a moderate SW breeze across the waters S of 07N Mon through Wed night. REMAINDER OF THE AREA... A ridge extends into the discussion area from 30N136W to 21N116W. Moderate trades generally prevail between the ridge and monsoon trough, and area freshening W of 130W and the ridge sharpens to the S between 130W and 145W. A pulse of long period NW swell is beginning to enter the waters N of 29N between 121W 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 continue propagating farther S across the waters to N of 27N between 119W and 133W on Sun night. Fresh NE trades and 6 to 8 ft seas are forecast from 09N to 15N W of 136W in association with weak low pres embedded in the monsoon trough on Sun and Mon. Seas of 8 ft are expected across the waters N of 22N between 116W and 130W on Tue morning, then will subside to less than 8 ft on Tue night. Another pulse of long period N swell will then propagate southward across 30N to the W of 124W. Fresh to locally strong NE winds and 8 to 11 ft seas are expected N of 29N W of 122W on Wed. $$ Stripling