000 AXPZ20 KNHC 270228 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Feb 27 2020 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 0130 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: A strong cold front has passed by N of the area in the Gulf of Mexico now across the Yucatan Peninsula with strong high pressure building in the wake of the front. Storm force winds are now developing in the Gulf of Tehuantepec and will persist through Thu morning before diminishing to gale force Thu afternoon, with gale force winds persisting into early Sun. Very large and dangerous seas to 21-23 ft will build with these impressive winds, peaking around Thu morning. Marine interests transiting across or in the vicinity the Gulf of Tehuantepec should be aware of this very strong gap wind event, and take the necessary action to avoid these hazardous marine conditions. Gulf of California Gale Warning: A tight pressure gradient exists across the region with surface troughing analyzed across far NW mainland Mexico and sharp ridging down along the Gulf of California. An earlier scatterometer pass indicated gale force winds in the northern and central Gulf, and at a minimum frequent gusts to gale force will remain forecast through this evening with fresh to strong winds elsewhere across the Gulf. Seas are up to 8-11 ft with these winds. The pressure gradient will gradually slacken tonight with winds diminishing to 20 kt or less across the entire Gulf by Thu afternoon, along with seas subsiding to less than 8 ft. Moderate to fresh northerly flow will persist through the end of the week. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03/HSFEP2 NHC or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from near 07N85W to 04N97W. The ITCZ continues from 04N97W to 03N110W to 06N125W to 04N140W. Scattered moderate convection is noted from 02N to 05N between 95W and 100W, and also from 03N to 07N between 123W and 135W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about the storm warning in the Gulf of Tehuantepec, and the gale warning in the Gulf of California. Elsewhere, high pressure prevails over the offshore waters W of the Baja California peninsula. Fresh to strong NE winds are moving through Baja California passages from the Gulf of California into the open Pacific offshore waters as indicated by recent scatterometer data, with moderate to fresh winds elsewhere N of 20N. Seas are up to 8-9 ft downwind of these strong gap winds. These winds and seas will diminish and subside through the overnight hours as conditions improve in the Gulf of California. Meanwhile, mainly gentle W-NW winds are noted S of 20N along with 4-7 ft seas in long period mixed swell. Looking ahead, a new set of NW swell will propagate into the waters offshore of Baja California this weekend, with seas building to 8-11 ft. Seas will continue to build into early next week, reaching 8-13 ft, while NW-N winds also increase to fresh to strong as very strong high pressure builds in from the NW. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Large NW swells generated by a storm force gap wind event in the Gulf of Tehuantepec will propagate into the waters of Guatemala and El Salvador by early Thu and continue into the upcoming weekend before subsiding Sun. Seas will reach to 16 ft along the offshore boundary between Guatemala and Mexico. Gulf of Papagayo: Mainly light and variable winds and 4-6 ft seas in mixed swell prevail at present. High pressure building N of the area by the end of the week will increase offshore winds to moderate to fresh on Thu, becoming fresh to strong Thu evening. Strong to near gale force winds are then expected on Fri, possibly reaching minimal gale force during the upcoming weekend. Gulf of Panama: Mainly moderate northerly winds will increase to fresh to strong across the Gulf of Panama and downstream to near 04N or 05N beginning on Fri as high pressure builds N of the area. Winds will continue to pulse through the upcoming weekend. Elsewhere, gentle to moderate winds and seas of 4-6 ft in mixed, long period swell will prevail the remainder of the week into early next week. REMAINDER OF THE AREA... A set of NW swell is across the NW waters N of 20N, with seas of 8-11 ft, along with moderate to fresh trades. The NW swell will shift slightly SE through Thu before decaying Thu night. Another set of NW swell will move into the area by the end of the week into the weekend. Meanwhile, trades N of the ITCZ to about 15N will increase to fresh to strong tonight into Thu due to a weak perturbation moving across the area. These increasing winds will build seas to 8-11 ft. Looking ahead, very strong high pressure will build across the area from the NW this weekend into early next week. Trades across the W-central waters may increase to minimal gale force due to the tightening gradient, with fresh to strong trades elsewhere N of 05N and W of 120W. Seas will build to 12-16 ft in the areas of strongest winds. $$ Lewitsky