000 AXPZ20 KNHC 011431 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1431 UTC Wed Feb 1 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 1415 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Fresh northerly winds will increase to fresh to strong this evening with seas building back to near 8 ft by early Thursday. Strong high pressure building over the Gulf of Mexico by Thursday will allow gap winds to reach gale force by Thursday night, diminishing to just below gale force Friday, before pulsing again to minimal gale force Friday night and Saturday night. Seas in and downstream of the Gulf of Tehuantepec will reach 8 to 11 ft with each pulse of gale force winds. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough axis extends from 04N86W to 03N94W to 02N103W. The intertropical convergence zone axis extends from 20N103W to 04N117W, then resumes from 05N120W to 01N138W. Scattered moderate convection is from the equator to 03N between 99W and 102W. Another trough axis extends from 1009 mb low pressure over northwest Colombia into the offshore waters to 01N80W. Scattered moderate convection is from 04N to 07N east of 79W to the Pacific coast of Colombia. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Weak high pressure of 1019 mb located just west of the offshore zones near 27N120W is supporting gentle to moderate breezes across the area, including the Gulf of California. Seas are mostly 4 to 6 ft across the open waters. Northwest swell will move into the waters off Baja California Norte late Thursday through Saturday with seas building to 8 ft N of 28N and west of Guadalupe Island, then subsiding Sunday. Looking ahead, moderate northerly winds along the coast of Baja California will increase to 15 to 20 kt by early Saturday as high pressure builds west of the area. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong trade winds through the southwest Caribbean Sea will promote pulses of fresh to strong mainly overnight gap winds through the Gulf of Papagayo and off Puerto Sandino, Nicaragua over the next several nights. The duration of these pulses will be a few hours, but seas may reach 8 ft downstream. In addition, fresh gap winds will pulse through the Gulf of Panama each evening, with strong winds occasionally off the Azuero peninsula and outside the Gulf of Panama. Light to gentle winds, and combined seas of 3 to 5 ft, will continue elsewhere outside of the swells originating near the gap wind regions. REMAINDER OF THE AREA... A tight pressure gradient associated with a deep 991 mb low pressure area centered near 35.5N138W is supporting winds to gale force just north of the area, behind a cold front reaching from 30N130W to 18N140W. Winds have diminished below gale force south of 30N, but fresh to near gale force southwest to west winds persist north of 25N and west of the front. Long period northwest swell will continue to propagate into the region with combined sea heights reaching 12 to 18 ft west of the front. The front will weaken as it shifts slowly eastward through Thursday. Winds will diminish to 15 to 20 kt from 28N to 30N between 130W and 140W into Thursday, but lingering swell will keep seas to 12 to 15 ft. Otherwise, a weak surface trough extends from 12N116W to 04N119W, moving west at around 10 kt. Only isolated showers are occurring near this trough. Aside from the winds and seas west of the front, mixed northeast and northwest swell of 8 to 12 ft covers the area roughly from 06N to 25N between 126W and 140W. This swell will encompass much of the region west of 120W by late Thursday, with the northeast component decaying and northwest swell dominating the sea state by then. Meanwhile, 8 to 9 ft northwest swell will persist over much of the area from 20N to 30N through Sunday once the above mentioned cold front decays. $$ LEWITSKY