000 AXPZ20 KNHC 262205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2135 UTC Tue Dec 26 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ..SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure extending southward from Texas to southern Mexico is maintaining N-NE strong breeze in the Gulf of Tehuantepec. N-NE winds are expected to remain in the 20-30 kt range over the Gulf of Tehuantepec during through Wednesday night before pulsing back up to minimal gale force early on Thursday as another southward surge of high pressure takes place along the eastern slopes of the Sierra Madre mountains to southeastern Mexico. Model guidance indicates that this next episode of gale force winds is likely to possibly continue into Saturday before weakening on Sunday. Seas of 8-9 ft in mainly NE swell will propagate downstream from the gulf to near 10N and 101W by Friday. Refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough axis extends from a 1009 mb low at 05N78W to 06N100W. The ITCZ extends from 06N100W to 09N115W to beyond 07N140W. Scattered moderate convection exists within an area bounded by 09N111W to 09N122W to 07N125W to 06N110W to 09N111W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the special features section above for details on a soon to end Gulf of Tehuantepec Gale event. Aside from the Gulf of Tehuantepec event described above, winds should be fresh breeze or weaker and seas less than 8 ft for the remainder of the Mexican Offshore Waters through Sunday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate high pressure gradient in the western Caribbean will continue to support fresh to strong NE winds from 09N to 11N east of 90W, including the Gulf of Papagayo, through early Saturday with seas to 7-9 ft in mixed NE wind waves and SW swell. The remainder of these Offshore Waters has fresh breeze or weaker winds and seas less than 8 ft through Sunday. REMAINDER OF THE AREA... Long-period NW swell is producing peak seas centered near 20N135W of around 10 ft. These are propagating southeastward and slowly diminishing. A new pulse of long-period NW swell of about the same wave height is now reaching the northwestern corner of our area and it too will spread southeastward over the next few days while gradually diminishing. On Friday and Saturday the E tradewinds in the vicinity of 15N120W will reach fresh to strong breeze as the pressure gradient tightens between a trough along the ITCZ and high pressure to the north. An E swell generated by these tradewinds will contributed toward combined seas of 8 to 10 ft near the vicinity of 15N125W. A mid to upper level trough extends from a cyclonic circulation located at 22N119W southwestward to 10N125W. This is helping to support scattered moderate and isolated strong convection over a large area centered at 15N110W. $$ Landsea/Aguirre