000 AXPZ20 KNHC 210932 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Sep 21 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 0600 UTC surface analysis and satellite imagery through 0940 UTC. ...TROPICAL WAVES... The axis of a tropical wave is along 105W and from 06N to 20N, moving west at 10 to 15 kt. There is no significant convection associated with this wave. The axis of a tropical wave is along 115W from 06N to 20N, moving west at 10 to 15 kt. Scattered moderate isolated strong convection is seen from 09N to 19N between 110W and 116W. The axis of a tropical wave is along 127W from 04N to 17N, moving west at around 10 kt. Convection remains limited near the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 13N88W to 15N110W to a 1010 mb low pressure near 13N118W to 07N128W. The ITCZ continues from 07N128W to 07N140W. Aside from the convection associated with the tropical waves, scattered moderate convection is N of 02N E of 82W, N of 11N between 87W and 97W, from 05N to 10N between 91W and 104W, and from 07N to 11N between 131W and 137W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak pressure gradient across the region is supporting light to gentle variable winds over the Baja California and SW Mexico offshore waters. Earlier altimeter data showed seas of 3 to 5 ft over these areas where SW and NW swell are converging. Recent scatterometer data shows gentle to locally moderate SE winds along the Gulf of California where seas are up to 3 ft. For the forecast, high pressure will build along Mexico this evening and will support both a gap wind event in the Gulf of Tehuantepec and moderate to locally fresh NW winds along the SW coast of Mexico. Fresh to strong winds are expected to begin in Tehuantepec tonight, increasing to strong to near gale force on Wed and potentially gale force Wed night. Seas will build to 10 ft with this gap event, which is expected to end by Sat. Otherwise, surface ridging will build over the Baja offshore waters on Wed, which will result in gentle to moderate NW winds continuing through the weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate southerly winds will prevail across the offshore waters of Costa Rica, Panama, Colombia and Ecuador during the forecast period, with seas of 4-6 ft in SW swell. Mainly light and variable winds are forecast across the offshore waters from Guatemala to northern Costa Rica, with seas of 3-5 ft also in SW swell. In the Papagayo region expect moderate NE-E winds through Tue. REMAINDER OF THE AREA... A broad area of low pressure associated with both a tropical wave and a 1010 mb low located about 900 miles SW of the southern tip of the Baja California peninsula is producing disorganized shower activity. These two features are forecast to merge within the next day or two. Environmental conditions are forecast to be somewhat conducive for development, and a tropical depression could form within the next few days while the system moves generally NW. By late Friday, however, the system is forecast to move over cooler waters and into a stable environment, which should inhibit further development. Please, refer to the latest Tropical Weather Outlook, at www.hurricanes.gov for more details. Surface ridging continue to dominate the open waters NW of this broad area of low pressure. This pattern continues to support moderate to locally fresh NE to E winds from 10N to 25N to the W of 115W with seas generally in the 5 to 7 ft range. Otherwise, moderate to locally fresh southerly winds will prevail S of the monsoon trough W of 120W. $$ Ramos