000 AXPZ20 KNHC 270903 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Nov 27 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... Gulf of Tehuantepec Gale Warning: A tight pressure gradient is across southern Mexico between high pressure building over the western Gulf of Mexico and relatively lower pressure over the deep tropics. Gap northerly winds in the Gulf of Tehuantepec are 30-40 kt with seas in the range of 11 to 16 ft. The strong gale winds will slowly diminish to 30-35 kt on Monday afternoon and below gale force during the evening hours. Swell from the gap wind event with 8 ft or greater will reach more than 500 nm offshore of the Gulf of Tehuantepec by late on Monday. Another round of gale force winds is expected Friday night. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 08N81W to 07N92W to 09N102W to 09N111W, where scatterometer data indicates that the ITCZ axis begins and then continues to 10N130W to beyond 10N140W. Scattered moderate convection is from 07N to 11N between 87W- 107W. Isolated moderate convection is from 07N to 14N between 106W and 123W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features paragraph above for information on the Gulf of Tehuantepec Gale Warning. Gentle to moderate northwesterly winds and slight seas will continue today ahead of a cold front approaching the area from the west. The front will cross the offshore areas off Baja California today and the northern Gulf of California on Tuesday. NW winds will increase to fresh to strong off Baja California Norte in the wake of the front today and tonight. Seas will build to 8 to 12 ft in NW swell, with 8 ft swell reaching as far S as the Revillagigedo Islands by Tuesday night. Fresh to strong NW flow will also follow the front in the northern Gulf of California tonight into Tuesday, with seas building to the range of 4 to 6 ft. Winds will diminish Tuesday into Wednesday as the front weakens and dissipates, but seas greater than 8 ft will persist in open waters through late week as another round of reinforcing swell moves into the region. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Expect a typical nocturnal maximum of around 25 kt across the region through early Tuesday morning, diminishing to 15 to 20 kt by mid afternoon. Seas will build to a maximize of around 7 ft each morning near sunrise. Light to gentle N to NE winds, and 3 to 5 ft seas are expected elsewhere through Friday N of the monsoon trough. Moderate southerly winds, and 4 to 6 ft seas, are forecast S of the monsoon trough. Northerly swell generated in the Gulf of Tehuantepec will reach the western part of forecast zone PMZ111 (offshore waters of Guatemala and El Salvador) building seas up to 11 ft through tonight. REMAINDER OF THE AREA... A cold front is analyzed from near 30N123W to near 24N130W, where it becomes a dissipating front to 20N140W. ASCAT data indicates fresh to strong NE winds in the wake of the front from 19N to 23N while recent altimeter data farther upstream indicate seas of 8 to 14 ft west of the front. $$ NR