000 AXPZ20 KNHC 250809 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Dec 25 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehunatepec Storm Warning: Winds to near 50 kt are likely over the Gulf of Tehuantepec through the morning, with seas building to as high as 24 ft. The storm force winds and dangerously high seas are result of strong high pressure and cold air moving across the western Gulf of Mexico, across the Tehuantepec isthmus and into the Gulf of Tehuantepec. Winds will diminish to strong gales by this afternoon as the high pressure shifts eastward, and persist into early Sat before diminishing. A large plume of seas of 8 ft or greater will extend well SW-W of the Tehuantepec region from this event. Marine interests transiting across or in the vicinity of the Gulf of Tehuantepec should be aware of this upcoming gap wind event, and take necessary action to avoid hazardous marine conditions over the affected waters. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N78W to 06N95W. Segments of the ITCZ extend from 06N95W to 07N122W, and from 07N126W to beyond 07N140W. Scattered moderate isolated strong convection is noted from 07N to 12N between 120W and 125W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features for details about an upcoming Gulf of Tehuantepec storm force gap wind event. Gulf of California: The combination of high pressure north of the area in the Great Basin of the United States, high pressure over north central Mexico and a trough near the Gulf of California is resulting in strong NW winds along the length of the Gulf. Seas are estimated to be as high as 9 ft in the southern Gulf. These winds and seas are expected to gradually diminish through Fri afternoon as the areas of high pressure weaken and shift east, with moderate NW winds and 2 to 4 ft seas expected across the Gulf by Sat afternoon. Looking ahead, strong NW winds may again impact the northern Gulf of California Mon night into Tue as a cold front moves into the region. Fresh to strong northerly gap winds may be ongoing off the Pacific coast of Baja California Sur north of Los Inocentes, although this should be diminishing through early morning. Elsewhere, mainly gentle to moderate NW-N winds will prevail across the offshore waters of Baja California through today. Winds will increase to moderate to fresh mainly north of Cabo San Lazaro toward the upcoming weekend as the pressure gradient tightens between a ridge west of the region and a trough over the Gulf of California. Large NW swell will propagate into the waters west of Baja California Sat night through Sun night with seas building to 8-11 ft. Looking ahead, fresh to strong NW winds will accompany a cold front moving through the area Mon into Tue, with reinforcing NW swell allowing seas to 12 ft off Baja California Norte. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh to strong NE-E winds will pulse across the Papagayo region the next several days as high pressure remains in place over the western Caribbean. Swell generated during a strong upcoming Gulf of Tehuantepec gap wind event is expected to affect the offshore waters of Guatemala and El Salvador late tonight through Sat. Seas will build up to 15-20 ft through late today. Otherwise, gentle to moderate winds will prevail on either side of the monsoon trough, except occasionally fresh near the Gulf of Panama. REMAINDER OF THE AREA... A broad surface trough is along and north of the ITCZ near 125W. The gradient between this feature and relatively higher pressure north of the area was supporting fresh to strong trade winds from roughly 08N to 12N between 120W and 130W, but recent scatterometer satellite passes suggest the trough is dampening out and the winds are diminishing. A recent altimeter satellite pass showed seas to to 9 ft were still in this area. Farther north, a cold front emerging out of the north central Pacific is starting to move east of 140W and south of 30N, and will weaken as it continues to move eastward to the north of 20N through late Sun. A large area of NW swell in excess of 8 ft will accompany the front, and encompass the waters west of 125W and north of 08N by early Sat. Seas may reach as high as 13 ft in the waters north of 25N and west of 130W. This front will likely dissipate through Sun, but another front will move eastward across the waters north of 25N early next week. High pressure building in the wake of this front will support persistent fresh trades over the tropical waters from roughly 10N to 20N west of 120W Sun through Tue, with seas 8 to 11 ft in a mix of wind waves and NW swell. $$ Christensen