000 AXPZ20 KNHC 170912 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Jan 17 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 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to low pressure of 1012 mb located near 06N101W to 05N112W. The ITCZ axis continues from 05N112W to 06N130W to beyond 05N140W. Isolated to scattered moderate convection is noted near the low center from 04N to 08N between 101W and 106W, and from 05N to 08N between 123W and 131W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front is moving across the northern Gulf of California and Baja California Norte. A recent scatterometer pass indicates SW winds of 20 to 30 kt in the Gulf of California N of 30N. Gentle to moderate southerly winds are seen over the central part of the Gulf with light and variable winds across the southern Gulf of California. A ridge dominates the offshore waters of Baja California Sur. The same ASCAT pass shows moderate NW winds downwind of Cabo San Lucas to about 21N109W associated with the periphery of the ridge. In the Gulf of Tehuantepec region, gentle southerly winds are observed. Long-period NW swell continues to propagate across most of the offshore forecast waters of Mexico, with seas of 10 to 13 ft N of Punta Eugenia, and 8 to 11 ft between Cabo San Lazaro and Punta Eugenia. Seas of 6 to 8 ft are noted elsewhere. For the forecast, fresh to strong winds will persist in the northern Gulf of California through this morning as the above mentioned cold front moves E of area. Seas to 8 ft are expected with these wind speeds. Light to gentle winds will prevail in the Tehuantepec region through the week along with 4-6 ft seas. Long-period NW swell will continue to propagate across the offshore waters of Baja California with seas of 9 to 12 ft N of Cabo San Lazaro by this afternoon. This swell event will reach the Revillagigedo Islands by Wed afternoon while gradually subsiding. Seas of 6 to 8 ft are expected across the offshore waters of Baja California by Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Recent satellite derived wind data provide observations of moderate to fresh NE to E winds across the Gulf of Papagayo. Moderate northerly winds are blowing in the Gulf of Panama and near the Azuero Peninsula. Light to gentle winds are noted per scatterometer data elsewhere. Long-period NW swell spreading across the area has raised seas to the range of 6 to 9 ft over the offshore waters from northern Costa Rica to Guatemala per latest altimeter data pass over these waters. Elsewhere, seas are generally in the 4 to 7 ft range. For the forecast, mainly moderate to fresh winds will prevail in the Papagayo region through Fri, then winds are forecast to increase again to fresh to strong speeds Fri night and Sat. Gentle to moderate winds are expected in the Gulf of Panama, and east of the Azuero Peninsula the remainder of the work-week. Seas from northern Costa Rica to Guatemala offshore waters will subside by late today while building to 5 to 7 ft between Ecuador and the Galapagos Islands. Winds will be moderate or weaker elsewhere through at least the next several days. REMAINDER OF THE AREA... As previously mentioned, a cold front extends across the northern Gulf of California and Baja California Norte, then continues SW to near 24N120W to 22N130W where it becomes stationary to near 24N140W. Winds have diminished to 20 kt according to scatterometer data in the wake of the front, but long period NW swell with significant wave heights as high of 15 ft continue to spread across the northern forecast waters behind the front. Elsewhere, a surface ridge dominates the waters N of 10N west of about 110W. Recent ASCAT data passes generally depict light to gentle winds under the influence of the ridge, except for moderate to fresh NE winds confined to the southern periphery of the ridge, where a tighter pressure gradient exists between the ITCZ and 15N. Long- period NW swell dominates most of the forecast region, with seas of 8-11 ft across most of the waters west of 90W. For the forecast, large and long-period NW swell will continue to propagate across most of the forecast waters through at least Wed. The cold front is forecast to dissipate in about 24 hours while reaching the waters near 20N. Seas are expected to gradually subside across the forecast area over the next couple of days. Fresh NW winds following in behind the front are forecast to spread across the waters W of Baja California Norte today, then across the waters W of the northern part of Baja California Sur through early Wed before diminishing to moderate speeds. Weak low pressure of 1012 mb along the monsoon trough is located near 05N101W. This system is producing isolated to scattered moderate convection from 04N to 08N between 101W and 106W. The low pressure is forecast by model guidance to shift W-NW through late Wed, but remain rather weak. It could open-up into a trough by Fri. $$ GR