000 AXPZ20 KNHC 281003 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 348 UTC Fri Oct 28 2016 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. ...SPECIAL FEATURES... Tropical Storm Seymour has become post-tropical, and is located near 22.4N 122.8W at 0900 UTC, moving N at 7 kt. Estimated minimum central pres is 1006 mb. Maximum sustained winds are 30 kt with gusts to 40 kt. A small area of sheared convection is seen within 180 nm NE of the center. Seymour will continue to rapidly weaken and dissipate by Monday. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25. Gulf of Tehuantepec Gale Warning...a high pres ridge across eastern Mexico continues to produce a tight pres gradient across SE Mexico. As a result, strong N winds will continue to blow across the Gulf of Tehuantepec and spill downstream through Friday night. Winds will pulse to minimal gale force, with the strongest winds occurring during the overnight and early morning hours. Seas will build to 12 or 13 ft during the periods of gale force winds. Fresh to strong winds will continue to pulse over the Gulf of Tehuantepec through Monday night. Model guidance suggests Gales will be possible once again Wednesday night through at least next Friday night. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 09N86W to 08N101W to low pres 1010 mb near 10N110W to 10N119W, then resumes from 16N127W to low pres 1010 mb near 13N132W to 10N138W. ITCZ continues from 10N138W to beyond 10N140W. Scattered moderate and isolated strong convection is present within 60 nm either side of a line from 15N130W to 12N135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section for details on a persistent Gulf of Tehuantepec high wind event. Gentle to moderate NW winds prevail across the waters offshore of the Baja California peninsula. Winds will slowly diminish this weekend, as a dying cold front moves E and the pres gradient weakens. 5 to 7 ft seas in NW swell will subside to 4 to 5 ft this weekend, then build to 6 to 9 ft by Sunday as another cold front and a new pulse of NW swell moves across the northern waters. In the Gulf of California, light and variable winds are expected today as an elongated NW to SE trough sets up across the gulf. Low pres is forecast to develop in the far northern Gulf of California by early Sunday. Winds SE of the low are forecast to increase to fresh to strong Sunday, pulsing through early next week. Seas will be 2 ft or less across the northern gulf through the weekend, building to 4 to 7 ft as the winds increase, with 2 to 4 ft seas expected over the southern half during this time frame. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate W to SW winds are found S of the monsoon trough, while gentle W to NW winds prevail N of the trough. Latest altimeter data shows seas ranging between 4 to 6 ft, primarily in long period SW swell. As SW swell decay, seas will subside to between 3 and 4 ft this weekend. REMAINDER OF THE AREA... A weakening cold front curves SW from 30N124W to 26N126W to 22N130W. Moderate to fresh NW winds are occurring behind the front and associated NW swell supports seas to 12 ft. Gentle to moderate winds are present ahead of the front. The front will stall by tonight, then dissipate Saturday. NW swell generated behind the front will continue to propagate SE and mix with seas generated by Seymour. This will result in an area of confused seas from 21N to 26N between 119W and 125W through tonight. Another cold front will reach the area tonight and bring a reinforcing batch of large NW swell. Moderate to fresh NE winds will prevail W of 130W between 10N and 25N. Combined seas of 7 to 11 ft in this area today will subside to between 7 and 9 ft tonight. $$ cam