000 AXPZ20 KNHC 230920 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0920 UTC Wed Oct 23 2019 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 92W south of 19N, moving west around 10-15 kt. Scattered moderate isolated strong convection is noted from 10N to 15N between 90W and 94W. The axis of a tropical wave is near 105W south of 18N, moving west around 10-15 kt. Scattered moderate convection is noted from 13N to 15N between 105W and 107W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N77W to 11N92W to 09N97W to 12N120W to 10N130W. The ITCZ continues from 10N130W to 10N140W. Scattered moderate convection is occurring within 240 nm south of the monsoon trough east of 81W, and within 90 nm of the monsoon trough between 118W and 124W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Overnight scatterometer data indicates a ridge axis extends across the Baja California waters with gentle to moderate NW to N winds across the region. Corresponding altimeter passes indicate seas are generally running 5-7 ft across these waters. Seas will subside through the rest of the week as residual NW swell decays and gentle to moderate offshore winds prevail across the region. Gulf of California: Partial scatterometer data shows moderate NW winds over portions of the northern and central Gulf of California. These winds will diminish later today. Strong high pressure is expected to build over the Great Basin Thu into Fri, and the associated pressure gradient will support strengthening winds over the northern Gulf by late week. Expect fresh to strong NW winds over the northern Gulf Thu with seas building to 8 ft by late Thu night. Fresh to strong winds will develop over the central Gulf Fri, then diminish on Sat. Gulf of Tehuantepec: Strong northerly gap winds are likely ongoing across the Gulf of Tehuantepec, and seas are expected to build to 8-9 ft downstream of the Gulf this morning. This gap wind event is expected to end on Thu. A stronger gap wind event is forecast to start late Fri night as a strong cold front moves across the western Gulf of Mexico. Gale conditions are possible Sat into Sat night as a strong north-south pressure gradient sets up across the region. Seas are expected to build to 12-13 ft with this event on Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate SW winds with 4-6 ft seas prevail south of the monsoon trough across the offshore waters of Central America, Colombia, and Ecuador. Little change is expected through the weekend. A set of long period SW swell will move northward into the region today, but seas are expected to remain less than 8 ft across the offshore waters. Looking ahead, seas will build to 8 ft in mixed swell this weekend well offshore of Guatemala and El Salvador. REMAINDER OF THE AREA... A high pressure ridge extends southeastward across the northern waters toward the Revillagigedo Islands. Moderate to fresh NE to E winds prevail roughly west of a line from 30N127W to 12N135W per recent scatterometer data. Earlier altimeter passes and recent model guidance suggest seas are likely still 7-10 ft in mixed swell and NE wind waves. High pressure centered well north of the region will remain nearly stationary and gradually weaken through Thu, allowing these winds to diminish and seas to subside through late week. Elsewhere, 8 ft seas are noted in the vicinity of the monsoon trough between 116W and 127W in association with a couple of weak low pressure areas. These conditions are expected to subside by tonight. Southerly swell moving into the far southern waters today may result in a brief period of 8 ft seas south of the Equator and west of 100W. A surge in the monsoon flow, combined with southerly swell, could produce another area of 8 ft seas from 04N to 08N between 100W and 105W Thu night. $$ Reinhart