000 AXPZ20 KNHC 282144 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Jul 28 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 2130 UTC. ...SPECIAL FEATURES... Frank has degenerated into a post-tropical cyclone with maximum sustained winds of 30 knots. The cyclone was center near 24.1N 124.9W, or about 955 miles w of the southern tip of the Baja California Peninsula, at 2100 UTC Jul 28, moving WNW, or 295 degrees at 06 kt. Frank is expected to and gradually dissipate over the next 48 hours. This is the last advisory issued on Frank. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. A tropical low pressure is analyzed along the monsoon trough at 11N110W, and is estimated at 1009 mb. Scattered moderate isolated strong convection is observed mainly s of the low, from 08-10N between 107-114W. This low has a medium chance of developing into a tropical cyclone in the next 48 hours. The low and associated winds have been included in the latest High Seas forecasts issued under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC. ...TROPICAL WAVES and TROPICAL LOW... The remnant low of former tropical cyclone Georgette is centered near 21N134W, and is estimated at 1010 mb. An earlier Rapid SCAT pass indicated fresh to strong ENE winds within 150 nm N of the center and suggested the system may be opening up into a trough. Seas of 7-10 ft were noted in the area of strongest winds. The low is forecast to weaken to an open trough overnight and extend from 20N138W to 23N139W by Fri. A tropical wave is analyzed from 08N to 16N along 113W/114w, and has been moving W at about 10 kt. Scattered moderate to strong convection was noted within 180 nm either side of the wave axis from 12N to 14.5N. A second tropical wave analyzed over the w Caribbean from 11-22N along 82W will move w off the Central American coast tonight, then slow it's forward speed as it continues w through the Gulf of Tehuantepec area Fri night into early Sat enhancing the northerly drainage flow around sunrise Sat. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends WNW from the Pacific coast of Costa Rica near 09N84W to 08N90W to 12N105W, then through an embedded 1009 mb low pressure near 11N110W, then continues W to 11N120W, where scatterometer winds indicate a transition to an ITCZ, which continues SW to through 07N135W to beyond 08N140W. Scattered moderate to strong convection was noted within 180 nm either side of the the monsoon trough between 85W and 95W. Scattered moderate isolated strong convection was noted within 120 NM S of the axis between 104W and 108W. ...DISCUSSION... N of 15N E of 120W: A west to east orientated surface ridge is building from 21N120W to 17N104W. The pressure gradient northeast of the ridge will support gentle to moderate nw winds across the open Pacific waters through Fri night, then the gradient will relax some with light to gentle nw flow expected into early next week. Mostly expect seas of 4-6 ft. Considerable convection continues along the Pacific coast of Mexico and the Gulf of California, roughly within 45 nm either side of a line from 20.5N105.5W to 29N112.5W. Otherwise...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 to gentle southerly winds across the Gulf of California waters through Fri. Moderate to fresh southerly flow, with 3-5 ft seas, is then forecast across the northern Gulf of California from Fri night to late Sat night. Fresh northerly flow is expected across the Gulf of Tehuantepec during the overnight hours through Sat night. Guidance suggests locally strong n flow on Sun, Mon and Tue nights with seas building to 8 ft. S of 15N E of 120W: See section on tropical wave and lows. Moderate to locally fresh ne-e winds are expected across, and just downstream of the Gulf of Papagayo during the overnight hours through the middle of next week. Long-period cross-equatorial SW swell, in the form of combined seas of 6-9 ft, has propagated n to along 10N between 90-115W. These seas are forecast to subside to less than 8 ft on Sat night. W of 120W: See special features above for information on the remnants of Georgette and Frank that will gradually dissipate through Fri night. A tropical low will move w into the area near 11N120W on Fri night with the possibility of tropical cyclone development. $$ Cobb