426 AXPZ20 KNHC 230132 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Dec 23 2024 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 0100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between persistent high pressure over eastern Mexico and low pressure within the eastern north Pacific monsoon trough will continue to support gale-force gap winds in the Gulf of Tehuantepec through tonight. Presently, strong N to NE winds extend beyond the Tehuantepec coast to near 250 nm offshore. Seas within and just downwind of the gale force winds at expected to peak near 13 ft. The high pressure will shift east by early Mon and weaken across Mexico, with the pressure gradient loosening. This will cause winds to diminish below gale force by early Mon with fresh to strong northerly pulses thereafter into Tue night, then moderate to fresh through Wed before diminishing. Please see the latest NWS High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and https://www.nhc.noaa.gov/marine/offshores_eastpac.php for more details. Significant NW swell: A large, complex, and powerful low pressure system north of the area will move NE through tonight, followed by another similar low pressure system sweeping just north of the area waters Mon through Tue. These systems are generating several rounds of large NW swell that will propagate into the area through the week and into next weekend. This evening, seas greater than 12 ft cover the waters west of a line from near Punta Eugenia in Baja California to 07N133W. This large NW swell will continue to spread SE through Mon while decaying while a reinforcing set quickly moves in behind. The large swell will peak across the offshore waters of SW Mexico mid-week, and just beyond the offshore waters of Central America thereafter. Peak seas will be around 22 ft tonight near 30N140W. Please see the latest NWS High Seas Forecast issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 06N108W. The ITCZ extends from 06N108W to 07.5N127W to beyond 06N140W. Scattered moderate convection is noted from 02N to 09N between 79W and 93W, and from 06N to 09N between 130W and 134W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features Section for information on a Gale Warning in the Gulf of Tehuantepec, and significant NW swell that will impact the waters offshore Baja California through the week and into next weekend. Aside from those conditions, 1024 mb high pressure is centered near 27.5N127.5W, with an associated ridge extending southeastward to offshore of Cabo Corrientes. The pressure gradient between this area of high pressure and a trough over NW Mexico is supporting moderate northerly winds across the Baja California waters, while gentle to moderate winds prevail south of 20N to offshore of Manzanillo and inside the Gulf of California. Seas are in the 4 to 7 ft over the open waters off Mexico to near Cabo San Lucas. Elsewhere across the Baja waters, seas are 8 to 15 ft from Punta Abreojos north and northwestward. Seas are 3 ft or less inside the Gulf of California. For the forecast, other than the aforementioned Gale Warning in the Tehuantepec region and the significant NW swells, high pressure west of the area will maintain moderate northerly winds pulsing to fresh at times offshore of Baja California through Tue, then becoming fresh to strong from Cabo San Lazaro northward Tue night through Thu night, with gentle to moderate winds across the remainder of the waters. Fresh to strong winds will be in the northern Gulf of California late Tue night through Wed as a cold front moves through the region. Significant NW swell will continue to spread southeastward to impact most waters through the week. Peak seas of 15 ft or higher offshore of north and central Baja California are expected this afternoon and tonight, peaking across south and central Baja offshore waters Mon and Tue. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The pressure gradient between a surface ridge extending southward over the western Caribbean Sea and the EPAC monsoon trough is supporting fresh to strong NE gap winds in the Papagayo region. Seas are 5 to 7 ft across this area. Gentle to moderate winds prevail elsewhere north of the monsoon trough, with moderate to fresh winds in the Gulf of Panama. South of the monsoon trough and 07N, gentle to moderate S to SW winds and 3 to 5 ft seas in moderate S to SW swell prevail, except for seas of 6 to 9 ft well offshore of western Guatemala, where NW swell from the Gulf of Tehuantepec gap wind event persists. Weak 1009 mb low pressure is south of the Gulf of Panama near 06N79W. Active convection is present S of 07.5N from the coast of Colombia westward across the near and offshore waters of Panama and Costa Rica, and extends beyond 90W. For the forecast, the pressure gradient between high pressure extending southward over the western Caribbean and the eastern north Pacific monsoon trough will support fresh gap winds pulsing to strong winds in the Papagayo region into Tue, then moderate to fresh thereafter. Gales in the Tehuantepec region will generate northerly swell and rough seas well offshore Guatemala through tonight. Elsewhere, winds will be moderate or weaker with moderate seas through mid-week, pulsing to moderate to fresh in the Gulf of Panama at times. A surge of at least fresh NW to N winds may move across the offshore waters of Guatemala mid- week. Seas will build Wed as the strong NW swell moves into the regional waters. ...REMAINDER OF THE AREA... Please read the Special Features section about large NW swell over the waters north of the Monsoon Trough/ITCZ through the next several days. A cold front is just north of the NW waters with moderate to fresh SW winds occurring over the waters just southeast of 30N140W. High pressure of 1024 mb is ahead of the front near 27N127.5W. Light to gentle anticyclonic winds are elsewhere north of 23N and east of the front to 120W. The pressure gradient between the high pressure and lower pressure in the vicinity of the ITCZ is supporting moderate to fresh winds north of the ITCZ to 23N and west of 118W, and locally strong within 210 nm of the ITCZ west of 123W. Across the remainder of the open waters, including south of the ITCZ, gentle to moderate trades prevail. Aside from the large swell discussed above, seas are mainly in the 5 to 8 ft range, except 6 to 9 ft downwind of the Tehuantepec region due to a gale-force gap wind event. For the forecast, other than the large NW swell discussed in detail in the Special Features sections, little significant change in winds are forecast over the next several days, while a front manages to push SE of 30N140W Mon, decaying over the northern waters into mid-week. New high pressure will build into the region behind this front and increase trade winds to fresh to strong west 130W Mon night through mid-week. Meanwhile, seas of 8 ft or greater will cover most of the waters west of 110W by Mon evening, then west of 100W Tue evening, then west of 90W Wed evening. $$ Lewitsky