000 AXPZ20 KNHC 100300 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0300 UTC Wed Jun 10 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 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...TROPICAL WAVES... A tropical wave extends from the western Caribbean Sea southward across Costa Rica along 84W, moving westward around 10 kt. Scattered moderate convection is noted from 04N to 10N between 81W and 89W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 09N97W to 11N115W. A portion of the ITCZ extends from 10N120W to 10N128W, then continues from 06N137W to beyond 06N140W. Scattered moderate isolated strong convection is occurring within 180 nm south of the monsoon trough between 95W and 100W. Scattered moderate convection is noted within 120 nm south of the monsoon trough between 112W and 115W, and within 120 nm south of the ITCZ between 120W and 128W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh NW flow continues this evening over the northern Gulf of California and near the coast of Baja California Norte, between an offshore high pressure ridge and lower pressure over northern Mexico. Earlier altimeter data over the Baja offshore waters indicated seas were 6-8 ft in NW swell. Elsewhere, moderate W winds are noted near the coast of southern Mexico between Acapulco and the Tehuantepec region. Light to gentle winds prevail elsewhere across the forecast waters. The local pressure gradient will relax over the northern waters tonight, allowing wind speeds to diminish across the region. Winds will strengthen Fri into this weekend as an enhanced gradient develops between offshore high pressure and low pressure troughing over the SW United States and NW Mexico. Increasing NW swell will build wave heights to 8 ft or greater in the Baja California Norte waters this weekend. Farther south, a Gulf of Tehuantepec gap wind event is expected later this week as a cold front crosses the western Gulf of Mexico. Expect strong to near gale-force northerly winds Thu night through the weekend, with overnight gale-force pulses possible Thu night and Fri night. Combined seas will build to 8-12 ft in northerly wind waves and southerly swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The latest ash advisory for Sangay volcano indicates that the threat of volcanic ash over the offshore waters of Ecuador has diminished. Therefore, the offshore ashfall advisory is no longer in effect. A southerly swell event continues over the regional offshore waters this evening. Wave heights were recently analyzed to 8-10 ft between the Galapagos Islands and Ecuador, with seas to 8 ft noted offshore of Colombia and Panama. Moderate to fresh S to SW winds continue south of the monsoon trough, generally over the waters south of 09N. Cross-equatorial S-SW swell will continue propagating across the region through Wed night. This swell could produce hazardous surf conditions along the coasts of Panama and Costa Rica, as well as rough seas near the Azuero Peninsula and the entrance to the Gulf of Panama. Wave heights will gradually subside late this week, before another set of southerly swell enters the region late Sun and Sun night. REMAINDER OF THE AREA... A ridge extends SE from 1025 mb high pressure near 32N135W over the northern waters to near the Revillagigedo Islands. Earlier scatterometer data showed moderate to fresh trade winds between this ridge and the ITCZ west of 128W. Altimeter data indicates seas remain 7-8 ft west of 130W in NE wind waves and long-period SE swell. These trades are expected to diminish slightly as a weakening cold front approaches the far northern waters by early Thu. However, a smaller area of fresh winds and higher seas will continue west of 130W as a low pressure trough develops along the ITCZ. Elsewhere, long-period southerly swell dominates the waters south of 10N and east of 120W this evening. Wave heights peak around 8-10 ft west of the Galapagos Islands per recent altimeter data. This swell will continue propagating northward while gradually decaying over the next couple days. A pocket of 8 ft seas will persist through late week between 90W and 100W in residual southerly swell and locally enhanced flow south of the monsoon trough. $$ B Reinhart