452 AXPZ20 KNHC 232008 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2000 UTC. ...SPECIAL FEATURES... 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 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. Currently, seas greater than 12 ft cover the waters roughly west of a line from Baja California Sur to 05N140W with slightly lower seas ahead of the next set of 12 ft or greater seas which extends from west of 30N124W to 15N140W. Peak seas are near 20 ft over the NW waters. The large swell will reach the offshore waters of SW Mexico mid-week, and just beyond the offshore waters of Central America thereafter. 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 09.5N84W to 05N93W to 06N103W. The ITCZ extends from 06N103W to 08N132W to beyond 07N140W. Scattered moderate convection is noted from 04N to 07N E of 82W, from 04N to 07N between 102W and 112W, and from 07N to 10N between 128W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features Section on significant NW swell that will impact the waters offshore Baja California through the week and into next weekend. Fresh to strong winds, and seas of 8-10 ft prevail in the Gulf of Tehuantepec. Elsewhere, a ridge extends from 1027 mb high pressure centered near 28N128W to near the Revillagigedo Islands. 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 light to gentle winds prevail elsewhere including inside of the Gulf of California. Seas are in the 4 to 7 ft over the open waters off SW Mexico to 108W, while seas are 8 to 13 ft from Cabo San Lucas north and northwestward. Seas are 3 ft or less inside the Gulf of California except slightly higher near the entrance. For the forecast, fresh to strong winds in the Gulf of Tehuantepec will gradually diminish through midweek. 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 spread southeastward to impact most waters through the week. ...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, extending westward to near 88W. Seas are 5 to 7 ft across this area. Gentle to moderate winds prevail elsewhere north of the monsoon trough. South of the monsoon trough, gentle to moderate S to SW winds and 3 to 5 ft seas in moderate S to SW swell prevail. 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. 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 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 over the far NW portion of the discussion waters. A 1027 mb high pressure centered near 28N128W. The pressure gradient between these features is supporting fresh to strong SW winds over the far NW waters. Light to gentle anticyclonic winds are in the vicinity of the high center. The pressure gradient between the area of high pressure and lower pressure in the vicinity of the ITCZ is supporting moderate to fresh winds north of the ITCZ to 20N and west of 118W. Across the remainder of the open waters, including south of the Monsoon Trough/ITCZ, gentle to moderate trades prevail. Aside from the large swell discussed above, seas are mainly in the 5 to 8 ft range. For the forecast, other than the large NW swell discussed in the Special Features section, little change in winds are forecast over the next several days. The cold front mentioned above will decay 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 tonight through mid-week. Meanwhile, seas of 8 ft or greater will cover most of the waters west of 110W by this evening, then west of 100W Tue evening, then west of 90W Wed evening. $$ AL