000 AXPZ20 KNHC 011603 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Nov 1 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 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Minimal gale force winds are noted in the Gulf of Tehuantepec this morning with the assistance of the early morning drainage flow. Building high pressure and cooler, denser air follow a cold front expected to move through the western Gulf of Mexico late this evening and overnight. This will allow gap winds to increase to strong gales through Tue. Northerly swell will mix with longer period southerly swell to support seas in excess of 8 ft well downstream of the Gulf of Tehuantepec, with peak seas building back to near 20-22 ft by Mon morning. Please refer to the latest High Seas Forecast issued by the National Hurricane Center at: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. Potential Heavy Rainfall event: Tropical cyclone Eta over the western Caribbean along with a surge of moist southwesterly flow will support the potential for heavy rainfall across portions of Central America into early next week, particularly western Panama and Costa Rica to begin with, then spreading northwestward through mid week. Heavy rainfall from Eta may lead to life- threatening flash flooding and river flooding across portions of Central America, along with landslides in areas of higher terrain. Refer to statements provided by your national meteorological service for more details. ...TROPICAL WAVES... A tropical wave axis has been relocated to near 106W/107W from 02N-15N, moving W at around 10 kt. Scattered moderate isolated strong convection is noted from 09N to 16N between 106W and 110W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N83W to 11N95W to 12N107W to 1011 mb low pressure near 11N112W to beyond 11N140W. Scattered moderate isolated strong convection is observed from 07N to 11N between 110W and 115W, and from 11N to 14N between 115W and 120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for details on the Gulf of Tehuantepec Gale Warning. High pressure northwest of Baja California is supporting gentle to moderate northerly breezes across the Mexican offshore waters off Baja California and the Gulf of California. Seas of 2-4 ft prevail in both the open waters and in the Gulf of California. Seas will build to 4 to 6 ft in NW swell in the waters of Baja California through the early part of the week. Elsewhere, little change is expected through the next several days. Gentle winds persist south of Cabo Corrientes outside of the Gulf of Tehuantepec plume, with seas of 4 to 6 ft in mostly southerly swell. Little change is expected. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate south to southwest winds will prevail south of the monsoon trough through today, with isolated areas of fresh winds ahead and behind of a tropical wave. Large seas are likely off western Guatemala, related to the gale force gap winds in the nearby Gulf of Tehuantepec. Seas reaching 8 ft will mix with building SW swell and spread across the area beyond 120 nm off the coast from El Salvador to Costa Rica by late Tue. Farther south, a combination of fresh SW winds and building SW swell will allow seas to reach 8 to 9 ft off western Panama by tonight. REMAINDER OF THE AREA... High pressure dominates the waters north of 15N. The gradient between the high pressure and lower pressures associated with the monsoon trough will continue to support moderate to locally fresh NE trade winds from the monsoon trough to 20N and west of 115W, for the next several days. Seas are 5 to 7 ft across this region, in a mix of swell and easterly wind waves. Little change is expected through the weekend. A cold front is forecast to reach 30N140W by Mon evening with winds remaining 20 kt or less. Long period NW swell will follow the front with building seas of 8-10 ft. This swell event will propagate across the NW forecast waters this evening through Tue impacting the waters north of 25N and west of 134W. South of the monsoon trough, moderate to fresh S to SW winds prevail between 100W and 140W, where seas are 5 to 8 ft. Minor fluctuations in winds and seas are expected across this area through the weekend. Disorganized showers and thunderstorms located several hundred miles southwest of the coast of southern Mexico are associated with a trough of low pressure. Environmental conditions appear favorable for gradual development, and a tropical depression is likely to form by the middle of the week as the system moves westward to west-northwestward over the eastern Pacific. The latest Tropical Weather Outlook states that this system has a low chance of tropical cyclone formation through 48 hours, and a high chance through 5 days. $$ GR