000 AXPZ20 KNHC 182120 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1928 UTC Sat Mar 18 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... A gale warning will continue in effect for the Gulf of Tehuantepec through Monday. Strong winds and high seas will persist through Thursday morning as high pressure in the northern Gulf of Mexico enhances drainage flow across the Isthmus of Tehuantepec into the eastern Pacific Ocean. Winds are forecast to increase to 40 kt tonight through Monday morning with seas building up to 15 ft. Winds are forecast to diminish below gale force Monday night. Northerly swell generated by this gap wind event will continue to propagate southward and mix with swell generated in the Gulf of Papagayo region. This will result in combined seas of up to 9 ft in waters from 05N to 11N between 90W and 112W on Sunday, and between 90W and 118W on Monday. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The Intertropical Convergence Zone remains south of the Equator. A trough is analyzed from 08N86W TO 02N101W. A second trough extends from 10N121W to 02N124W. Isolated moderate convection is near the trough axes. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section for information on the Gulf of Tehuantepec gap wind event. A 1021 mb high pressure centered near 24N120W will maintain generally light to gentle breezes over much of the area through Sunday. A recent altimeter pass indicated 3 to 4 ft seas over the area. A weakening cold front is expected to push into northern Baja California Wednesday night and extend across the southern Gulf of California and southern Baja California by Thursday night. A tight pressure gradient will result between the front and high pressure building behind it supporting fresh to strong NW winds off the Baja California coast Thursday to Friday morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... High pressure will prevail over the northwest Caribbean and Gulf of Mexico, which will allow for the continuation of fresh to strong gap winds across the Gulf of Papagayo through mid next week. Fresh to strong N-NE winds are also forecast in the Gulf of Panama and downwind to about 05N at night. Seas will build to 5- 7 ft in this area, including offshore of the Azuero Peninsula through Sunday night. Otherwise, light to gentle winds and combined seas of 3-5 ft are expected to continue the next several days. REMAINDER OF THE AREA... High pressure of 1021 mb located near 24N120W will remain nearly stationary over the next 24 hours. A cold front is moving across the NW waters and extends from a weak 1015 mb low pressure near 28N135W to beyond 24N140W. The low will move NE and north of the forecast area in about 24 hours, dragging the weakening front across the north waters through Monday. A reinforcing cold front will enter the NW forecast waters Monday morning and is expected to reach northern Baja California early Wednesday afternoon. Moderate to locally fresh trades will persist elsewhere across the tropical Pacific with combined seas of 5-7 ft through Sunday. $$ GR