000 AXPZ20 KNHC 151607 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Dec 15 2020 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 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 1545 UTC. ...SPECIAL FEATURES... Gulf of Tehunatepec Gale Warning: A gap wind event is expected in the Tehuantepec area beginning late Wed afternoon and continuing through Sun night. Strong northerly winds are forecast to increase to gale force by Wed evening as a cold front moves across the Gulf of Mexico. Gale conditions and building seas to 12 ft will diminish by Fri morning. Please, read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from a 1009 mb low pressure over northern Colombia near 09N75W to 05N77W to 1010 mb low pressure near 07N103W to 08N120W. The ITCZ continues from 08N120W to 07N140W. Scattered moderate convection is noted from 03N to 07N E of 80W, and from 05N to 11N between 100W and 108W. Similar convection can be found from 07N to 13N between 110W and 123W and from 06N to 10N W of 120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to locally strong northerly winds with seas to 9 ft in the Tehuantepec region will diminish to moderate winds this afternoon and to light and gentle variable winds tonight. A new gap wind event is expected to begin late Wed afternoon, with winds increasing rapidly to gale fore winds early Wed evening. Please, see the Special Features section for more details. A ridge dominates the offshore forecast waters of Baja California. The pressure gradient between the ridge and lower pressures over mainland Mexico is resulting in fresh to locally strong NW winds N of 28N E of 121W. Long period NW swell contiunues to propagate across the waters N of Cabo San Lazaro with seas building up to 12-13 ft. This swell event will reach the Revillagigedo Islands later today. Gulf of California: Mainly moderate to fresh NW-N winds will prevail in the Gulf of California during the forecast period with the exception of fresh to locally strong winds beggining tonight and continuing through Wed night. Seas will remain under 8 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to fresh NE-E winds will prevail in the Papagayo region over the next few days with seas of 4-6 ft. Winds are expected to increase to fresh to strong Thu night through Sat night as high pressure builds over the western Caribbean. Gentle to moderate northerly winds are forecast in the Gulf of Panama, pulsing to 20 kt Thu and Fri nights as the tradewinds over the south-central Caribbean strengthens some. Elsewhere, gentle to moderate winds will prevail S of the monsoon trough with mainly gentle winds N of it. REMAINDER OF THE AREA... High pressure of 1029 mb located near 32N128W extends a ridge SE across the northern forecast waters to near the Revillagigedo Islands. The pressure gradient between the ridge and lower pressures in the vicinity of the ITCZ will continue to support a large area of fresh to locally strong trade winds, particularly from 10N to 21N W of 125W. Seas are in the 8 to 11 ft range within the area of the trades due to a combination of wind waves and NW swell. These winds will persist over the next 48 hours as high pressure remains in place. A weak low pressure of 1010 mb is analyzed along the monsoon trough near 07N103W, forecast to move westward with little change over the next 48-72 hours. Long period NW swell dominate most of the waters N of 10N and W of 115W this morning. Sea heights of 10-13 ft are noted per altimeter data W of Baja California norte to about 125W. Additional pulses of NW swell will reach 30N140W today, and again on Thu night. Swell of 8 ft or greater seas will dominate most of the waters N of 10N W of 110W through at least Wed night. $$ Ramos