000 AXPZ20 KNHC 282121 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Dec 28 2021 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 1930 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N74W to 09N82W to 06N94W to 06.5N100W. The ITCZ continues from 06.5N100W to 10N125W to beyond 08N140W. Scattered moderate isolated strong convection is noted from 05N to 08.5N between 79.5W and 84W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO A weak frontal trough has moved southward to along 30N and Baja California Norte and across the extreme north portions of the Gulf of California today. A weak and narrow ridge of high pressure extends southeastward and underneath the front across the waters west of central and southern Baja California to near 17N110W. Fresh to strong W to SW winds prevail over the northern Gulf of California, while moderate to fresh W to NW winds prevail across the Baja Norte offshore waters north of the front. South of the front, moderate to locally fresh northerly winds prevail west of the remainder of the Baja California peninsula. Light to gentle winds are noted elsewhere. Seas are in the 6-9 ft range west of the Baja California peninsula and 3-5 ft elsewhere over the open waters off Mexico. Seas of 3-5 ft are seen over the north and central portions of the Gulf of California with 2-3 ft seas elsewhere over the Gulf waters. The frontal trough across Baja Norte will move south to near Punta Eugenia tonight and dissipate. Strong W to SW winds will continue across far northern portions of the Gulf of California tonight before quickly weakening Wed morning. Seas there are expected to build to 5-7 ft tonight. Elsewhere across the Baja offshore waters, weak high pressure will supporting moderate NW to N winds overnight before weakening and becoming variable Wed. Deep layered low pressure will move across southern California and then Baja Norte Thu night through Fri, accompanied by a significant cold front with active weather. The front will move ESE across the Baja Norte offshore waters Thu afternoon and across the Baja Peninsula and Gulf of California Thu night through Fri. Looking ahead, a gale force gap wind event is expected to commence across the Gulf of Tehuantepec region late Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR Fresh E gap winds prevail over the Gulf of Papagayo region with light to gentle winds elsewhere north of the monsoon trough. Moderate N winds are over the Gulf of Panama, with gentle to moderate winds over the remainder of the waters south of the monsoon trough. Seas are in the 3-5 range across the forecast waters. Fresh gap winds will prevail over the Papagayo region throughout the week. Light to gentle winds will occur elsewhere north of the monsoon trough. Moderate N winds will prevail across the Gulf of Panama through Thu, with gentle to moderate winds elsewhere south of the monsoon trough. REMAINDER OF THE AREA... Deep layered low pressure continues to weaken just W of the area, with a 1014 mb surface low centered near 21.5N143.5W. Weak troughing extends eastward from the low along about 21N and across the far western portion of the discussion area. The pressure gradient between a high pressure ridge to the N and this area of low pressure continues to produce fresh to strong NE to E winds over the discussion waters from 22N to 27N and W of 128W, with seas 9 to 12 ft in N swell. This area of strong easterly winds will diminish in areal coverage tonight as the low continues to drift W and the pressure gradient weakens. Light to gentle winds are noted from 09N to 20N and west of 124W. Gentle to moderate winds the remainder of the discussion waters. An inverted surface trough extends from 23N124W to 13N126W. Associated moisture converging around this trough is triggering scattered moderate isolated strong convection from 11.5N TO 14N between 120W and 126W. NW to N swell continues to dominate seas across the region N of 12N and W of 120W with seas in the 7-10 ft range. Seas of 4-7 ft prevail elsewhere. The NW swell will slowly subside by midweek. The cold front expected across the Baja Peninsula late in the week will sink southward across the northern waters Wed afternoon through Sat before becoming stationary along about 18N. Moderate NW to N swell will accompany the front into the region. $$ Stripling