000 AXPZ20 KNHC 182111 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Jul 18 2016 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 2100 UTC. ...SPECIAL FEATURES... Hurricane Darby centered at 19.0N 132.0W at 2100 UTC Jul 18 moving west or 280 deg at 10 kt. The maximum sustained winds are 65 kt with gusts to 80 kt. The estimated minimum central pressure is 988 mb. Darby has moved over fairly cool water recently and convection has weakened considerably from earlier. Only scattered moderate convection is noted within 60 nm of the center band. Despite the weakening convection, Darby is still maintaining a well defined structure, and earlier scatterometer data indicated strong winds persist. Winds will gradually diminish as Darby moves westward, eventually reaching below tropical storm strength by the end of the week. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 KNHC for more details. Also, refer to the latest high seas forecast MIAHSFEP2/FZPN03 KNHC for more details on the wave forecasts associated to Darby. Tropical Storm Estelle was centered near 17.8N 115.8W at 2100 UTC Jul 18 moving west-northwest or 295 degrees at 9 kt. The maximum sustained winds remain 60 kt with gusts to 75 kt. The estimated minimum central pressure is 991 mb. Numerous strong convection is observed within 90 nm of the center with the convection becoming more symmetric. Scattered moderate isolated strong convection is currently noted elsewhere within 240 nm northeast and 120 nm southwest semicircles. The anticipated strengthening has been hampered by shear that is forecast to weaken, and Estelle is expected to strengthen to a minimal hurricane tonight or early Tuesday. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Also see latest high seas forecast MIAHSFEP2/FZPN03 KNHC for more details on the wave forecasts associated with Tropical Storm Estelle. ...TROPICAL WAVE... A tropical wave is analyzed north of 05N along 84W/85W and has been moving west at about 12 kt. The tropical wave is enhancing convection along the monsoon trough and the convection over Panama, Costa Rica and Nicaragua. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends from 09N85W to 09N95W to 11N110W. Scattered moderate convection within 120 nm south of the axis between 85W and 112W. ...DISCUSSION... North of 15N and east of 120W: The core of Estelle is passing over Clarion Island currently with strong winds and seas of 8 to 12 ft impacting the remainder of the Revillagigedo Islands as well. Estelle will produce swell of 8 to 10 ft impacting much of the area south of 25N and west of the Baja California peninsula through Tuesday. While significant wave heights will likely remain less than 8 ft in the area between Cabo San Lucas and Cabo Corrientes into the southern Gulf of California, occasional large southerly swell from Estelle is possible over the next couple of days. Meanwhile, moderate to fresh southerly flow is likely over the northern Gulf of California between ridging to the west and resident troughing over the Baja California peninsula. Fresh to briefly strong westerly gap winds are possible tonight over the northwest Gulf of California near 30N. By mid week, longer period northerly swell will mix with the southerly swell from Estelle over the waters west of Baja California Norte maintaining 6 to 8 ft seas overall. Farther south, the pressure gradient between high pressure over the Gulf of Mexico, and lower pressure across the tropical Eastern Pacific, will result in fresh to strong northerly flow across the Gulf of Tehuantepec tonight with seas 8 to 10 ft by late tonight and Tuesday morning. South of 15N and east of 120W: Aside from the southern portion of Estelle impacting the waters north of 12N and west of 105W through tonight, the main forecast issue will be fresh east gap winds into the Gulf of Papagayo during the overnight hours this week, with seas building to 8 ft as the resultant north to northeast wind waves mixes with long period cross equatorial southwest swell that will propagate northeast across the waters east of 110W this week. West of 120W: See special features above for information on tropical cyclones Darby and Estelle that will pass westward through the waters north of 15N. Longer period northerly swell is pushing south of 32N currently, and will mix with the southerly swell generated from Darby and Estelle over the waters north of 20N through mid week. $$ Cobb