000 AXPZ20 KNHC 251605 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Dec 25 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 1605 UTC. ..SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A high pressure ridge extending S over the Sierra Madre Oriental range from Texas is maintaining a gap wind event over the Gulf of Tehuantepec. Gale force winds will persist until Tuesday morning as a reinforcing shot of cold air enters the Gulf of Mexico. Thereafter, fresh to strong winds are expected to persist over the Gulf through Thursday night. Winds will be strongest at night due to nocturnal drainage flow. Seas in the Gulf of Tehuantepec should peak to around 14 ft on Tuesday morning, Strong to near gale force winds will sustain wave heights of 8 ft or greater through Thursday night. Another cold front entering the Gulf of Mexico could usher in the next gap wind event beginning on Friday according to latest model guidance. Please refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from a 1009 mb low at 06N78W to 06N87W to 06N96W where scatterometer data indicates that the ITCZ axis begins and extends to 09N112W to 09N122W to 08N131W to 10N140W. Scattered moderate convection is within 60 nm S of the axis between 103W and 105W, and between 118W and 122W. Similar activity is within 30 nm S of the axis between 110W and 113W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the special features section above for details on the ongoing Gulf of Tehuantepec Gale event. Elsewhere, mainly gentle to moderate winds with benign marine conditions are expected through Thursday. NW swell bringing seas in the range of 6 to 8 ft generated by strong winds off the coast of California could enter the far NW offshore waters of Baja California Norte on Tuesday. Low pressure over interior Mexico could combine with high pressure NW of the area to generate fresh to strong winds between Cabo San Lucas and Cabo Corrientes on Friday afternoon and evening. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong gap winds over the Gulf of Papagayo will continue pulsing through Friday night, with the broadest extent of the winds occurring tonight and Tuesday night. Seas will peak between 8 and 9 ft during this time frame. NE swell producing seas to 9 ft will impact some portions of the offshore waters of Guatemala through late tonight as swell originating from the Gulf of Tehuantepec gap wind event propagates S and SW through the offshore waters. Otherwise, gentle to moderate winds and seas of 5 to 7 ft can be expected through Friday. REMAINDER OF THE AREA... A trough over the NW corner of the area extends from 32N135W to 24N140W. The trough will weaken as it moves to the W of the area through Wednesday. Fresh to strong S winds that were formerly present N of 27N and up to 120 nm east of the front have subsided. Residual NW swell of 8 to 11 ft generated to the NW of this boundary earlier will slowly propagate SE and disperse through Wednesday as seas W of 120W and N of 10N subside to around 8 ft. A reinforcing set of NW swell will maintain sea heights between 8 and 9 ft N of 20N and W of 130W on Wed and Wed night. Forecast models are also hinting at increasing winds late Tuesday and Wednesday as the pressure gradient tightens between the aforementioned trough currently extending from 32N135W to 24N140W and high pressure building to its N and NE. Winds in the vicinity of the trough are currently forecast to reach fresh speeds Tue night through Thu. The combination of the wind waves and NW swell is expected to produce seas to between 8 and 9 ft in this area. Elsewhere, moderate to fresh winds will prevail as seas generally run between 6 and 8 ft. $$ Aguirre