000 AXPZ20 KNHC 270318 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Nov 27 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure over eastern Mexico and the remnants of Otto, currently located well south-southwest of the Gulf of Tehuantepec continues to support gale force winds in the 30-40 kt range over the Gulf of Tehuantepec with seas reaching 13-14 ft. An altimeter pass provided observations of these wave heights. The pressure gradient across the Tehuantepec area is expected to lessen on Sunday as high pressure weakens north of the area, and the remnants of Otto dissipates. This will allow winds to diminish below gale force early Sunday afternoon. Winds will further diminish to 20-25 kt by Sunday evening. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across the Gulf of Panama near 08.5N79W to the remnants of Otto near 09N97W. The ITCZ axis extends from 08N100W to 09N115W to 11N125W then resumes at 11N134W to 09N140W. Scattered moderate convection is from 09N to 11N between 117W and 124W. No significant convection elsewhere. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the latest Gulf of Tehuantepec gale force gap wind event. Outside of the Gulf of Tehuantepec region, northwesterly swell dominates the offshore waters off the western coast of the Baja California peninsula with seas in the 7-9 ft range as depicted by the most recent altimeter passes. Seas are in the 4-6 ft range elsewhere across the Pacific offshore waters and 1-3 ft over the Gulf of California. Continued pulses of northwesterly swell will keep seas above 8 ft over the offshore waters off the western coast of the Baja California peninsula through the middle of next week. Winds will increase to near gale force in the Gulf of California north of 29.5N tonight through early Sunday both ahead of and behind a cold front moving across the area. A reinforcing cold front will reach the far NE forecast waters and northern Baja on Sun evening and move E of the area by Monday morning. Fresh to strong W-NW winds will be associated with the reinforcing front. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Otto degenerates into a trough of low pressure and the last advisory on this system was issued by the National Hurricane Center at 26/2100 UTC. The remnants of Otto, currently located near 09N97W, will continue to move westward for a day or two. Light to gentle winds with seas in the 4-6 ft range are noted north of 10N, with moderate to locally fresh southwest flow and combined seas of 4 to 6 ft south of 10N. Little change is forecast through early next week. REMAINDER OF THE AREA... A cold front is moving through the NE waters and extends from 30N115W to 25N123W to 23N130W. A 1031 mb high pressure located near 33N144W follows the front and extends a ridge across the northern forecast waters to near 21N113W. Fresh to strong winds prevail NW of the front as depicted by the most recent ASCAT pass. The pressure gradient between high pressure northwest of the area and lower pressure in the vicinity of the ITCZ is supporting a large swath of fresh to strong trades north of the ITCZ to near 24N and west of 130W. Combined seas over this are in the 10-14 ft range in a mix of northwesterly swell and northeasterly generated wind waves. The cold front will move eastward across northern Baja and NW Mexico tonight and Sunday while the high pressure will remain nearly stationary over the 24 hours. Under this weather pattern, the pressure gradient will remain tight enough to support strong to near gale force trade winds and seas in the 13-14 ft over the next 48 hours. $$ GR