000 AXPZ20 KNHC 082159 CCA TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2139 UTC Wed Feb 8 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... Gulf of Tehuantepec Gale Warning: Strong broad high pressure will build southwestward from the Gulf of Mexico Thursday night, and southwestward to along the eastern section of Mexico. This will create a tight pressure gradient along southern Mexico that will lead to the development of gale force winds starting late Thursday night through Friday night. Please see the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The axis of an ill-defined intertropical convergence zone extends along 01N west of 95W. No signficant convection is observed. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Troughing along the Gulf of California is squeezed between 1024 mb high pressure near 30N121W and stronger high pressure over north central Mexico is resulting in fresh to strong northwest winds over the central Gulf of California near Loreto. Seas are likely reaching 6 ft in this area. Similarly moderate to fresh northwest winds are observed off the coast of the Baja California peninsula north of Cabo San Lazaro and west of 115W, with seas to 7 ft. Moderate northwest to north winds are noted elsewhere. The pressure gradient will loosen through Thursday allow winds to diminish across the region. Moderate winds will prevail through the next several days. Long period northwest swell will propagate into the waters off Baja California Norte by late Friday. Please see Special Features for information regarding the Gulf of Tehuantepec. The plume of seas to 9 ft with a component of northwest swell will reach 300 nm downstream to the west- southwest of the Gulf of Tehuantepec through Saturday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The pressure gradient between high pressure ridging extending southwest from the central Atlantic to the western Caribbean Sea and lower pressures over the southwestern Caribbean Sea and Central America in combination with overnight drainage flow will support pulses of fresh to strong northeast winds through the Gulf of Papagayo during the nighttime hours through Friday. Model guidance continues to suggest that new broad and strong high pressure north of the area Thursday will allow for a much stronger pulse and longer lasting of gap winds through the Gulf of Papagayo Thursday night into early Friday, with a plume of seas to 8 ft reaching to roughly within 300 nm to the west and southwest of the Gulf of Papagayo with seas reaching a range of 8-9 ft by Friday night. In addition, strong northerly winds will move into the Gulf of Panama and off the Azuero peninsula Friday through Saturday with seas building to 8 to 10 ft. REMAINDER OF THE AREA... Southwest winds to near gale force along with areas of showers and a few thunderstorms are evident ahead of a cold front moving east of 30N140W. Northwest swell of 12 to 16 ft accompanies the front, with 8 to 12 ft seas noted northwest of a line from 30N130W to 20N140W. Upper support for the front will lift northeast of the area tonight, allow the front to weaken as it moves eastward to 125W over the next 48 hours. Winds will diminish accordingly. Seas will subside as well, although wave heights to 12 ft in northwest swell will linger north of 25N and west of 130W through late Thursday. The remnant northwest swell in excess of 8 ft will propagate across most of the region north of 20N and west of 120W through late Friday, then decay to below 8 ft from west to east over most of this area though Saturday. Farther south, an upper low centered near 10N120W is supporting a few showers near 07N113W. This will dissipate through late Thursday as the upper low lifts north out of the deep tropics. Altimeter data and buoy reports indicate seas are still near 8 ft in some areas of the deep tropics between 125W and 130W, likely in a mix of northwest swell and local trade wind waves. This will dissipate through Thursday as trade winds diminish and the older swell subsides. High pressure will build north of the area behind the front Friday, allowing fresh trade winds just as a new round of northwest enters the area. This combination will result in seas to 8 ft south of 20N and west of 130W by late Friday. Looking ahead, winds diminish and seas subside below 8 ft through Sunday. $$ CHRISTENSEN