000 AXPZ20 KNHC 172155 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Sep 17 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 1800 UTC surface analysis and satellite imagery through 2000 UTC. ...TROPICAL WAVES... A tropical wave along 111W N of 04N, and is drifting west. It shows up well in the lower to middle levels of the atmosphere, south of a upper level ridge. Scattered moderate convection is noted within 180 nm west of the trough axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N84W to 15N105W to 07N120W. Another segment of the monsoon trough extends from 15N125W to 1012 mb low near 14N137W to 13N140W. Scattered moderate isolated strong convection is noted from 06N to 13N between 89W and 95W. Scattered moderate convection is evident from 08N to 12N between 98W and 104W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Weak high pressure is building southward across the waters off Baja California Norte. Moderate northerly winds and seas across the offshore waters are currently off of Baja California Norte and this pattern will continue through Sun. Northerly 6-7 ft swell will build southward toward Baja California Norte by Saturday into Sunday. A weak surface trough will develop well offshore Baja California Sur Sat and Sun. This will maintain light to gentle winds and slight seas through early next week. Farther south, strong gap winds and moderate seas are possible through the Gulf of Tehuantepec by Sun related to developing low pressure in the southwest Gulf of Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate S to SW winds persist south of the monsoon trough. Elsewhere, gentle winds prevail north of the monsoon trough. Combined seas are currently in the 4 to 7 ft range in a mix of wind waves and S to SW swell, except 5 to 8 ft south of Panama. The swell is starting to taper off, and combined sea heights will subside through tonight and Fri. REMAINDER OF THE AREA... The remnant low of Karina is located near 24N126W with a central pressure of 1009 MB at 1800 UTC moving W at 7 kt. The latest scatterometer showed moderate winds along the low. Seas are likely 8 to 9 ft within 90 nm of the low. There is no significant convection associated with this system. The low will continue moving westward and gradually weaken to a surface trough by Fri. The trough will drift southwestward on Sat through Sun. Seas will subside below 8 ft through early Fri. Gentle to moderate NW winds are noted along and northwest of a trough reaching from 30N130W to 25N140W. The trough was previously a stalled frontal boundary, and it will dissipate through early Fri. A recent altimeter satellite pass indicated seas reaching 8 ft just north of a 1012 mb low pressure area along the monsoon trough near 14N137W. Winds are likely near 20 kt within 120 nm to the north of the low pressure. This feature and its attendant winds and seas will shift west of the area through late Fri. Little to no showers or thunderstorms are noted near the low pressure. Farther east, seas are near 6 to 8 ft in an area along the monsoon trough from 06N to 10N between 105W and 115W. This is due to a combination of moderate to fresh SW winds along with longer period SW swell. Winds and seas will diminish through Fri in this area. $$ Christensen