000 AXPZ20 KNHC 200835 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Jan 20 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 0600 UTC surface analysis and satellite imagery through 0630 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N83W to 04N93W. The ITCZ axis extends from 04N93W to 04.5N102W, then resumes west of a surface trough from 04N112W to 04N125W to 06N140W. Scattered moderate convection is noted from 06N to 08N between 133W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge is just west of the Baja California offshore waters, leading to mainly moderate north winds, where seas are 7 to 9 ft in NW swell. Moderate NW to NNW winds are in the southern Gulf of California, as well as near Cabo Corrientes. Seas are likely 3 to 5 ft in this area. Gentle winds are elsewhere with 3 to 7 ft seas. For the forecast, developing moderate to fresh N winds in the Gulf of Tehuantepec will diminish by this afternoon. A dissipating cold front extending from near the California/Mexico border to 30N122W will move S this morning while continuing to dissipate. Behind the front, fresh to strong NW to NNW winds are expected in the Gulf of California tonight through Sun, with seas building to 9 ft in the south and central Gulf by Sat night. These winds will filter through Baja California gaps to west of the peninsula. A pulse of NW swell N of Cabo San Lazaro will keep seas there in 7 to 9 ft range through today. Looking ahead, another cold front should move from north to south across the Baja California area Sun night into Mon. This will cause fresh NW winds and increasing NW swell west of Baja California Norte Sun night and Mon. Strong NW to N winds are likely in the Gulf of California Mon into Tue, once again filtering through Baja California gaps westward. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE winds are across the Gulf of Papagayo and downwind to near 88W. Moderate N winds are in the Gulf of Panama. Light to gentle winds prevail elsewhere. Seas are generally in the 4 to 6 ft range, except SW of the Galapagos Islands where seas of 6 to 7 ft in NW swell are noted. For the forecast, fresh to strong NE winds will pulse in the Gulf of Papagayo through Sat night, building seas to around 7 ft. Winds will be moderate or weaker elsewhere through at least the next several days with seas subsiding to 3 to 5 ft during the upcoming weekend. Fresh to strong winds should return to the Papagayo region Mon night into early Tue. A SW swell event will build seas to 5 to 7 ft from offshore Ecuador to the Galapagos Islands early next week. REMAINDER OF THE AREA... High pressure ridging extends from the north-central waters to just west of the Revillagigedo Islands and covers the waters north of the ITCZ and west of around 110W. Moderate to fresh NE to E trade winds are noted N of the ITCZ to around 23N, except locally strong from 14N to 21N. Seas are 7 to 10 ft N of the ITCZ in mixed NE wind waves and NW swell. Moderate or weaker winds and 5 to 7 ft seas prevail elsewhere. A weak 1012 mb low is near 05N109W along a surface trough extending from 08N103W through the low to 03N112W. Numerous showers are in the vicinity of these features S of 10N between 98W and 112W, while isolated moderate convection has recently developed within 75 nm NW of the trough. For the forecast, long-period northwest swell supporting combined seas of 7 to 10 ft will continue to propagate across the waters N of about the ITCZ and west of 115W through the upcoming weekend, getting reinforced by a larger set of NW swell early next week. That set will build seas to around 15 ft N of 20N along 140W by Mon evening. Otherwise, high pressure will dominate most of the forecast waters north of the ITCZ ahead of a dissipating cold front which will try to drop S of 30N this morning. The high pressure will strengthen some during the weekend, in the wake of that decaying front, bringing an increase in the trade wind flow N of the ITCZ to about 20N and W of 120W by Sat, lasting through Sun. These winds combined with the NW swell will help to build seas to up to 12 ft in the trade wind belt. Another cold front may drop S of 30N late Sun into Mon with fresh to strong winds N of 28N between 118W and 128W through Mon night. The pressure gradient should weaken some thereafter allowing for winds to diminish slightly. $$ Lewitsky