000 AXPZ20 KNHC 200229 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Mar 20 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 0000 UTC surface analysis and satellite imagery through 0200 UTC. ...SPECIAL FEATURES... A gale warning will continue in effect for the Gulf of Tehuantepec through Monday night. Winds are forecast to remain up to 40 kt through early Monday morning, with seas building up to 14 ft. Winds will diminish to near gale force afterwards, however will briefly increase again to minimal 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, and cross equatorial SW swell. This will result in combined seas of up to 10 ft in waters from 04N to 11N between 90W and 120W on Monday. Strong winds and high seas will persist through Thursday morning as high pressure in the Gulf of Mexico enhances drainage flow across the Isthmus of Tehuantepec into the eastern Pacific Ocean. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... No ITCZ or Monsoon Trough is discernible at this time. A trough stretches from 15N128W to 07N129W. A second trough extends from 08N108W to 02N110W. Scattered moderate convection is from 07N to 10N between 111W and 119W...and near 08N123W. A diffluent pattern aloft is helping to induce this convective activity. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section for information on the Gulf of Tehuantepec gap wind event. A 1019 mb high pressure centered near 24N122W will maintain gentle to locally moderate northwest winds across the offshore waters west of Baja California through Monday with seas of 4 to 6 ft. By late Monday into Tuesday, expect NW winds in the 15-20 kt range within about 75 nm of the coast of Baja California as the pressure gradient slightly tightens there. A weakening cold front is expected to push into northern Baja California by late Wednesday. A tight pressure gradient will result between the front and high pressure building behind it. This will support fresh to strong NW winds off the Baja California coast Wednesday night through Thursday night. Seas off Baja California will build to 8-9 ft during that period. Winds are forecast to also increase across the north and central Gulf of California with the frontal passage Wednesday evening through Thursday, and across the southern Gulf of California Thursday afternoon through Thursday night. Currently, marine guidance shows SW winds of 20-25 kt and building seas of 6-7 ft ahead of the front and W-NW winds of 20-30 kt behind the front. 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 most of the forecast period with seas 8 to 9 ft. Fresh to strong north to northeast winds are also forecast in the Gulf of Panama and downwind to about 05N at night through Monday night with seas building up to 8 ft near 5.5N81W by early Monday morning. Otherwise, light to gentle winds and combined seas of 3-5 ft are expected to continue the next several days elsewhere. REMAINDER OF THE AREA... High pressure of 1019 mb located near 24N122W will remain nearly stationary over the next 24 hours. A cold front is moving across the NW waters and extends from a 1010 mb low pressure near 32N131W to 22N140W. A pair of altimeter passes indicated seas of 8-11 ft in NW swell in the wake of the front. The low will continue to move NE and away from the forecast area, dragging the cold front across the north-central waters through Monday. A reinforcing cold front will enter the NW forecast waters Monday morning, merging with the first front. This second front is expected to reach northern Baja California by late Wednesday. Seas will further build across the NW waters in the wake of the second front. Marine guidance shows seas of 8-12 ft NW of a line from 30N129W to 24N140W by Tuesday evening. A third cold front is forecast to reach the NW forecast waters late on Thursday, producing fresh to strong winds and building seas of 12-14 ft. $$ GR