000 AXPZ20 KNHC 200948 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Jul 20 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... Tropical Storm Estelle was centered at 19.0N 122.0W, or about 825 miles w-sw of the southern tip of the Baja California Peninsula at 0900 UTC Jul 20. Estelle is moving w, or 270 degrees at 11 kt. The maximum sustained winds are 60 kt with gusts to 75 kt. The estimated minimum central pressure is 990 mb. Scattered moderate to strong convection is currently noted within 75 nm over the sw quadrant. Scattered moderate isolated strong convection is observed elsewhere in bands within 180 nm either side of a line from 16N121W to 22N123W. Estelle is expected to remain a tropical storm. 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 Storm Darby centered at 20.0N 137.8W,or 1050 miles e of Hilo Hawaii at 0900 UTC Jul 20, moving w or 280 deg at 11 kt. The maximum sustained winds are 55 kt with gusts to 65 kt. The estimated minimum central pressure is 994 mb. Scattered moderate isolated strong convection is currently observed within 60 nm either side of a line from 19N138W to 21N138W. Darby is expected to only weaken slightly over the next couple of days. 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 WAVE... A tropical wave is analyzed n of 11N along 92W and has been moving w at about 10 kt. Scattered moderate to strong convection is noted within 60 nm either side of line from 12N90W to 14N95W to 14N99W. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends w from the pacific coast of Colombia at 09N79W across the Gulf of Panama and southern Panama to 08N78W TO 10N98W TO 08N111W TO 13N128W. Scattered moderate isolated strong convection is noted within 120 nm either side of a line from 07N81W to 07N90W to 11N97W to 08N112W to 11N121W. ...DISCUSSION... N of 15N e of 120W: See special features section above for details on tropical cyclone Estelle over the extreme sw portion of the area. An associated large area of combined seas of 8 ft and greater will shift w of 120W this evening. A surface ridge will build in the wake of Estelle tonight from 26N120W to 15N106W. The gradient ne of the ridge will support moderate nw-n winds across the waters this week, except increasing to a fresh nw breeze during the late afternoon and early evening hours. Combined seas of 4-7 ft are forecast to build to 5-8 ft on Fri and Sat. 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 Sat, then moderate southerly flow is expected on Sun. Strong to near gale force northerly flow will persist through sunrise this morning across, and just downstream of the Gulf of Tehuantepec. The resultant ne swell will propagate sw, and mix with long period cross-equatorial sw swell, with combined seas of 6-8 ft forecast between 95W and 102W through early Thu. Only fresh drainage flow is expected during the overnight hours the rest of the week. A surface low is expected to develop near 17N107W on Fri and move nw to near 22N113W with the potential for tropical cyclone formation. S of 15N e of 120W: An area of combined seas of 6-9 ft, will shift w across the discussion waters from 13-15N w of 117W today, in association with tropical cyclone Estelle which is centered just nw of the area. Moderate to locally fresh e winds are expected across, and just downstream of the Gulf of Papagayo during the overnight hours this week. The resultant e wind wave will mix with long period cross equatorial sw swell that will propagate ne across the waters between 90W and 112W, where combined seas to 9 ft are expected through Thu. Several surface lows are expected to develop along the monsoon trough this week. Model guidance differs on location and strength of the lows. A model consensus leads to solution of a low forming near 10N112W tonight, and moving w, with the pressure gradient supporting fresh to strong e winds within about 300 nm n of the low. Environmental conditions will favor tropical cyclone development in 3 to 5 days. W of 120W: See special features above for information on tropical cyclones Darby and Estelle that will pass westward through the central portion of the area 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. A tropical low is expected to move into the area near 10N120W on Thu night accompanied by fresh to strong e winds within 300 nm n of the center. Environmental conditions will favor tropical cyclone development in 3 to 5 days. $$ Nelson