000 AXPZ20 KNHC 140935 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Nov 14 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 0900 UTC. ...SPECIAL FEATURES... A gale warning remains in effect for the Gulf of Tehuantepec. A scatterometer pass at 0320 UTC showed 35-40 kt winds within 50 nm of the coast in the Gulf of Tehuantepec, and another small area of 35 kt winds near 13.6N96W. A ridge along the eastern slopes of the Sierra Madre Mountains combined with low pressure in the SW Caribbean is maintaining a tight pressure gradient across the Isthmus of Tehuantepec. Model guidance suggests that the current synoptic pattern will remain favorable for very strong gap wind flow through early Wed morning, with peak winds between 35 and 40 kt this morning. Max sea heights will be 12 to 16 feet, then subside slowly Tue. Winds will diminish below gale force Wed as the ridge weakens some. Northerly winds in the 20 to 30 kt range will continue to blow across the Tehuantepec region through Sat, then increase to gale force again Sat night as a strong cold front moves into the western Gulf of Mexico. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A discontinuous monsoon trough extends from 10N85W to 08N127W, then from 13N131W to 12N140W. Scattered moderate to strong is south of Panama to 06N E of 83W. Scattered moderate convection is within 75 nm of the trough axis between 91W and 127W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section for information regarding the ongoing Gulf of Tehuantepec gale warning. A ridge will dominate the waters W of Baja California the next several days. The pressure gradient W of Baja California will tighten slightly as high pressure shifts closer to the coast, resulting in fresh NW winds N of 28N between 116W and 120W today with seas building to 7 ft. Gentle to moderate NW winds are expected to persist across the Gulf of California. Elsewhere, mainly light to gentle winds and seas of 4 to 5 ft will prevail through Wed night. A weakening cold front will move across the northern Baja California peninsula on Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds and seas of 4 to 6 ft are expected N of the monsoon trough, which will fluctuate between 07N and 10N through Wed. Moderate to locally fresh S to SW winds and seas of 5 to 7 ft are forecast S of the monsoon trough through Tuesday. Fresh to strong SW winds south of Panama will build seas to 8-10 in the Gulf of Panama later today through Thursday. REMAINDER OF THE AREA... A 1012 mb low pressure area is centered near 19N131W moving NW at 10 kt. Peripheral scatterometer data this morning indicates outer winds associated with the low have diminished considerably during the past 12 hours, and latest altimeter data shows a max of 9 ft seas. Scattered moderate convection is noted within 60 nm NE of the low. A passing short wave trough and dry air aloft is expected to cause the low to weaken into a trough during the next 24 hours. Long period northerly swell will reach the NW portion of the discussion area today, but stay mainly N of 28N and W of 135W during the next 48 hours. Gentle to moderate winds and 4 to 6 ft will prevail elsewhere across the forecast area through Fri. $$ Mundell