000 AXPZ20 KNHC 031603 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Jan 3 2023 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... A 985 mb low pressure near 37N152W will rapidly deepen to a hurricane force 956 mb low pressure in 24 hours near 39N138W. A strong cold front extends southward and southwestward from this low. The cold front will enter the area, crossing 30N140W this evening, reach from 30N132W to 23.5N140W early Wed, and from 30N122W to 23N130W to 20N140W early Thu. Gale force winds are forecast on both sides of the front this evening through Wed evening, mainly north of 27N between 125W and 140W. The front will also usher in a large set of NW swell into the NW waters, with seas peaking near 28 to 30 ft Wed into early Thu along 30N. Seas of 20 ft or greater will reach as far south as 25N. Conditions will improve late Thu, but large NW to N swell will continue to progress southeastward across the forecast waters through Sat. Please read the latest High Seas Forecast at website: www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 10N86W to 09N91W to 06N99W to 07N104W. The ITCZ extends from 08N110W to 07N140W. Scattered moderate convection is noted from 04N to 08N between 77W and 85W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1020 mb high pressure associated with the subtropical ridge is centered near 25N123W. The ridge extends weakly eastward into the Mexican offshore waters. This pattern allows for light to gentle winds in the Gulf of California, occasionally to moderate speeds in the northern portion of the basin. Seas in the Gulf are 1-3 ft. Light to locally moderate northerly winds prevail in the offshore waters of Baja California. Seas in these waters are 6-9 ft in NW swell. Elsewhere in the offshore waters of Mexico, including the Gulf of Tehuantepec, light to locally moderate winds and slight to moderate seas are prevalent, except for moderate NNW winds noted near Cabo Corrientes. For the forecast, weak high pressure will prevail over the waters off Baja California through tonight, leading to gentle to moderate winds. S to SW winds off Baja California Norte will increase to fresh to strong late Wed as a cold front approaches the waters. The cold front will reach those waters Thu, then begin weakening as it reaches the northern Gulf of California Thu night. Very large W to NW swell will follow the front Thu night through Fri, with seas in the 16-21 ft range off Baja California Norte, and the 13-18 ft range off Baja California Sur. The next gap wind event in the Gulf of Tehuantepec is possible late Wed into Sat, with winds possibly briefly reaching minimal gale force Thu evening. Seas may build up to 11 ft late Thu into early Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Scattered showers and isolated thunderstorms continue to affect the waters offshore Panama and Colombia. Fresh NE to E winds are likely occurring offshore the Papagayo region, extending westward to 90W. Seas in these waters are 4-5 ft. Light to gentle southerly winds prevail south of the monsoon trough. Seas in the waters described are 3-6 ft, with the highest seas occurring SW of the Galapagos Islands. Elsewhere, moderate or weaker winds and slight seas are prevalent. For the forecast, moderate to fresh winds over the Papagayo region will increase to strong speeds on Wed and continue through Sun. Seas will approach 8 ft Thu night through Sat. Moderate to locally fresh northerly winds are expected in the Gulf of Panama Wed through the weekend. Gentle to occasionally moderate winds will continue elsewhere for the next several days with slight to moderate seas. REMAINDER OF THE AREA... Please see the Special Features section above for more on the Gale Warning over the NW waters. A 1020 mb high pressure associated with the subtropical ridge is centered near 25N123W. The ridge currently dominates the tropical eastern Pacific, maintaining fairly tranquil weather conditions. The pressure gradient between the high pressure system and a weak cold front north of our area result in moderate to locally fresh SW winds north of 27N. Seas in these waters are 8-11 ft in NW swell, confirmed by recent altimeter data. Moderate to locally fresh easterly winds are found between the ITCZ and 18N and west of 115W. Seas in the area described are 6-8 ft. Moderate southerly winds are noted south of the ITCZ and monsoon trough, along with seas of 5-7 ft. For the forecast, swell from the upcoming gale event described above will spread large seas in NW to N swell across the basin Thu through Sat, with 12 ft seas reaching as far south as 10N. Seas up to 10 ft from this swell will reach the Equator over the weekend. $$ Hagen