000 AXPZ20 KNHC 180948 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURES... Hurricane Darby centered at 18.5N 130.2W at 0900 UTC Jul 18 moving w or 275 deg at 09 kt. The maximum sustained winds are 70 kt with gusts to 85 kt. The estimated minimum central pressure is 985 mb. Scattered moderate isolated strong convection currently surrounds a 30 nm wide eye, roughly within 120 nm either side of a line from 17N128W to 20N131W, but the convection has been decreasing in both intensity and coverage over the past few hours, and Estelle is expected to weaken to a tropical storm with a day. 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 17.2N 114.0W at 0900 UTC Jul 18 moving w-nw or 290 degrees at 08 kt. The maximum sustained winds are 60 kt with gusts to 75 kt. The estimated minimum central pressure is 991 mb. Numerous strong convection is observed along a 180 nm wide band over the n semicircle of the system. Scattered moderate isolated strong convection is currently noted elsewhere within 180 nm either side of a line from 13N111W to 20N114W. The anticipated strengthening has been hampered by shear that is forecast to weaken, and Estelle is expected to strengthen to a minimal hurricane within a day. 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 n of 04N along 83W and has been moving w at about 12 kt. Scattered moderate isolated strong convection is noted within 180 nm either side of line from 06N77W to 06N90W. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends w from the pacific coast of Colombia at 07.5N78W to 08.5N98W. As described with the previously mentioned tropical wave, scattered moderate isolated strong convection is noted s of the monsoon trough, within 180 nm either side of line from 06N77W to 06N90W. Similar convection is observed within 60 nm either side of a line from 06N105W to 13N133W to 07N140W. ...DISCUSSION... N of 15N e of 120W: See special features section above for details on tropical cyclone Estelle which will continue westward across the sw portion of the discussion area, with the associated area of tropical storm conditions and greater shifting w of 120W on Tue night, while combined seas of 8 ft or greater will shift w of 120W early Thu. A surface ridge will build in the wake of Estelle from 26N120W to 15N103W on Thu setting up moderate anticyclonic flow around the ridge and across the open waters w of 108W. A nnw to sse orientated trough will meander e and w over the Baja California Peninsula, and the northern Gulf of California this week, supporting light and variable winds across the Gulf of California waters through Thu, with moderate southerly flow expected on Fri and Sat. The pressure gradient between high pressure over the Gulf of Mexico, and lower pressure across the tropical Eastern Pacific, will result in fresh to locally strong northerly flow across the Gulf of Tehuantepec tonight, and then repeating briefly on Tue night, with seas building to about 10 ft. S of 15N e of 120W: See special features section above for details on tropical cyclone Estelle centered just n of the area, with an associated area of fresh to strong southerly winds, and seas to 12 ft shifting w across the far nw portion of the discussion area this morning, with associated seas of 8-11 ft finally shifting w of 120W late Wed. Fresh e winds will develop briefly across, and just downstream of the Gulf of Papagayo during the overnight hours this week, with seas building to 8 ft as the resultant n-ne wind wave mixes with long period cross equatorial sw swell that will propagate ne across the waters e of 118W this week. Seas to 8 ft are expected to reach the pacific coast of Central America and Mexico from 11n to 16N on Wed. W of 120W: See special features above for information on tropical cyclones Darby and Estelle that will pass westward through the central portion this week. Combined seas of 7-11 ft primarily due to mixing swell, are expected to surround the large seas near the the cyclones, and cover the waters elsewhere to the n of 10N this week. $$ Nelson