000 AXNT20 KNHC 091759 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 159 PM EDT Wed Aug 9 2017 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...SPECIAL FEATURES... Tropical Storm Franklin is centered near 20.2N 93.9W at 09/1500 UTC or about 125 nm NNE of Coatzacoalcos Mexico and about 145 nm ENE of Veracruz Mexico moving W at 11 kt. Estimated minimum central pressure is 985 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Numerous strong convection is from 18N to 21.5N between 92W and 95W. Scattered moderate convection is elsewhere from 16N to 25N between 90W and 98W. See the latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT2/WTNT32 KNHC and the full Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. ...TROPICAL WAVES... A tropical wave is in the E Atlc with axis extending from 19N25W to 07N29W, moving W at 10-15 kt. The wave is in a region of mainly strong vertical wind shear and is experiencing extensive Saharan dry air and dust intrusion to its environment, which is hindering convection at the time. A tropical wave is in the central Atlc associated with a 1012 mb low near 17N55W. The wave axis extends from 23N52W to the low to 09N56W, and is moving W at 10 kt. The wave is in a region of mainly low to moderate vertical wind shear. Shallow moisture along with upper level diffluent flow support scattered moderate convection from 16N to 25N between 49W and 55W. Environmental conditions are forecast to become somewhat conducive for development of this system late this week and this weekend while it move WNW over the western Atlantic. A tropical wave extends is in the W Caribbean with axis extending from 22N79W 09N82W, moving W at 20-25 kt. The wave is in a region of strong vertical wind shear and mainly shallow moisture. A cluster of heavy showers and tstms is E of the wave axis between Jamaica and Cuba being supported by diffluent flow embedded in a broad upper level low centered just S of Jamaica. Scattered to isolated heavy showers and tstms are S of 12N mainly associated with the EPAC monsoon trough. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 12N16W to 08N28W to 06N39W. The Intertropical Convergence Zone axis extends from 06N39W to 06N48W to 08N51W. Aside from convection associated with the tropical waves, a surface trough is analyzed from 16N45W to 08N42W, which is supporting scattered moderate convection from 07N to 11N between 42W and 47W. ...DISCUSSION... GULF OF MEXICO... Tropical Storm Franklin continues to strenghen as it tracks W across the SW Gulf waters. Numerous heavy showers are S of 21N with isolated tstms noted just S of the storm center. Scattered tstms are noted in Franklin's rainbands S of 24N. Franklin is forecast to become a hurricane later today and reach the coast of Mexico as a hurricane tonight or early Thursday. Rapid weakening is expected after landfall in Mexico. For further information, please see special features section. Isolated showers and tstms are across SW Louisiana and adjacent coastal waters associated with a 1013 mb low over SE Texas and the tail of a stationary front extending SW to 27N97W. Fair weather and gentle to moderate ESE winds reign elsewhere across the basin. A surface ridge will build across the basin in the wake of the storm this upcoming weekend. CARIBBEAN SEA... Isolated showers associated with the outer bands of Tropical Storm Franklin are in the far NW Caribbean W of 85W. Farther east, a tropical wave is along 81W, however lacking significant convection. To the E of the wave, a cluster of heavy showers and tstms is between Jamaica and Cuba being supported by diffluent flow embedded in a broad upper level low centered just S of Jamaica. Scattered showers and isolated tstms are S of 12N mainly associated with the EPAC monsoon trough that extends from Costa Rica to Panama to NW Colombia. In the SE basin, shallow moisture and upper level diffluence support scattered to isolated showers S of 13N E of 65W, including the Windward Islands. Water vapor imagery show dry air across the remainder Caribbean, which supports fair weather. Otherwise, fresh to strong winds continue in the central basin between 70W and 76W continuing for the next two days. Fresh to strong winds are also in the Gulf of Honduras continuing through Friday morning. A tropical wave currently along 55W will enter the E Caribbean waters Thursday morning. ...HISPANIOLA... Clear skies prevail across the island being influenced by deep layer dry air as indicated by the experimental GOES-16 imagery. These conditions are forecast to continue through Friday when a surface trough will move just N of the Island supporting isolated showers. ATLANTIC OCEAN... A surface trough is moving across the central Bahamas supporting scattered showers and isolated tstms from 22N to 27N between 73W and 78W. Over the north-central waters, with lack of upper level support, a stationary front continues to weaken along 30N40W to 28N50W to 28N58W. Isolated showers are within 120 nm either side of the frontal boundary. A tropical wave in the central Atlc has medium chances of development into a tropical cyclone over the weekend as it moves over W Atlc waters. For further details on tropical waves, see section above. Otherwise, a 1022 mb high is centered near 27N38W, which is forecast to dissipate by Thu morning. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos