000 AXPZ20 KNHC 212044 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2040 UTC Fri Feb 21 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 1800 UTC surface analysis and satellite imagery through 2040 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: The pressure gradient between high pressure across the eastern slopes of the Sierra Madre Mountains in Mexico and the equatorial trough in the eastern north Pacific is supporting storm force across the Tehuantepec region. Seas are expected to build to near 22 ft tonight. The area of high pressure N of the area will weaken slightly tonight. This will loosen the pressure gradient, and winds will diminish below storm force. The area of high pressure will gradually continue to weaken through the weekend, loosening the pressure gradient and bring a gradual decrease in winds. By Sun afternoon, winds are forecast to diminish below gale force. Swell generated by this gap wind event combined with long period SW swell will produce a large area of 8 ft seas or greater covering the waters from 02N to 12N between 90W and 110W by Sun morning. Marine interest transiting across or in the vicinity of the Gulf of Tehuantepec this weekend should be aware of this gap wind event and take the necessary action to avoid hazardous marine conditions over the affected waters. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 06N77W to 02N84W to 04N101W. The ITCZ continues from 04N101W to 06N140W. Scattered moderate isolated strong convection was noted from 02N to 07N between 81W and 89W. Scattered moderate convection was noted from 04N to 07N between 113W and 117W. Scattered moderate isolated strong convection was noted from 06N to 09N between 127W and 131W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A Storm Warning is in effect for the Gulf of Tehuantepec. Please read the Special Features section for more details. Looking ahead, the next strong gap wind event, possibly to storm force, is possible the middle to end of next week. Elsewhere, a broad ridge extends SE across the offshore forecast waters W of Baja California producing light to gentle NW-N winds, and seas mainly of 4 to 6 ft. The ridge will weaken during the next few days in advance of an approaching cold front. The front will slowly dissipate as it moves across Baja California Norte and the northern Gulf of California through Sat. Winds will become moderate to locally fresh across the offshore waters W of Baja California as the gradient tightens in the wake of the front. Winds could reach 25 kt offshore of Cabo Corrientes by the end of the weekend into early next week. Seas are forecast to gradually build to 6-9 ft in NW swell behind the front this weekend. In addition, winds will briefly increase to 20 to 25 kt ahead and behind the front over the northern Gulf of California on Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... NW swell generated by the storm force gap wind event in the Gulf of Tehuantepec will propagate into the waters offshore Guatemala and El Salvador through Sun. Seas will reach up to 14-16 ft near 11N95W. Gulf of Papagayo: Fresh to strong winds will continue to pulse during the overnight hours across the Papagayo region through the weekend. Winds will diminish early next week as the pressure gradient weakens. Maximum seas will reach between 8-10 ft during this time period. Gulf of Panama: Fresh to occasionally strong north winds will pulse across the Gulf of Panama through the weekend, diminishing early next week. Maximum seas will build to 6-8 ft at times with these winds. Elsewhere, gentle to moderate winds and seas of 4-6 ft will prevail into early next week. Looking ahead, an unseasonably strong southerly jet is forecast to develop along the lee of the Andes over eastern Ecuador and SW Colombia late Sat night. During this time, environmental conditions appear favorable for heavy rainfall and localized flooding to develop due to strong topographical forcing. REMAINDER OF THE AREA... A cold front is analyzed from 30N123W to 27N123W to 21N135W. Fresh northerly winds prevails behind the front. The front has ushered in a set of NW swell into the NW waters, with seas in the 8-10 ft range. The front will gradually weaken as it shifts eastward toward Baja California Norte and the northern Gulf of California. High pressure in the wake of the front will support fresh to strong trade winds N of the ITCZ and W of 125W this upcoming weekend. Seas are forecast to build to 8 to 12 ft within the area of the trades. Fresh NE-E swells generated by gap wind events in the Gulf of Tehuantepec and Gulf of Papagayo will propagate far from its source region into an area from the equator to 13N between 90W and 110W this weekend, gradually decaying by early next week. $$ AL