000 AXNT20 KNHC 170504 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 103 AM EDT Tue Oct 17 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 0000 UTC surface analysis and satellite imagery through 0415 UTC. ...SPECIAL FEATURES... A cold front extends from the Florida Big Bend region SW to 26N90W to 20N95W then stationary to the Mexico coast near 19N96W. Strong high pressure continues to build in across the NW Gulf waters... southern Texas...and eastern Mexico generating a strong pressure gradient and inducing near gale to gale force N to NW winds S of 25N within 90 nm of the coast of Mexico. The front is expected to gradually weaken through Wednesday night with winds decreasing below gale force by Tuesday night. See latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...TROPICAL WAVES... A tropical wave extends from 06N53W to 14N51W moving W at 15-20 kt. The wave coincides with shortwave 700 mb troughing between 50W-56W and a maximum in 850 mb relative vorticity along the wave axis near 09N. Isolated moderate convection is from 07N-13N between 50W-55W. A tropical wave extends from 06N59W to 14N59W moving W at 10-15 kt. The wave coincides with shortwave 700 mb troughing between 58W-62W and a maximum in 850 mb relative vorticity along the wave axis near 13N. Isolated moderate convection is from 11N-18N between 55W-62W. A tropical wave extends from 08N77W to 21N76W moving W at 10-15 kt. The wave coincides with broad 700 mb troughing between 70W- 80W. Dry northerly flow aloft is noted on water vapor imagery on the eastern periphery of an upper level ridge anchored near 17N81W and continues to inhibit any significant deep convection with the wave at this time. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 10N14W to 07N26W. The Intertropical Convergence Zone axis extends from 07N26W to 07N38W to 06N50W. Scattered moderate convection is from 07N-13N between 13W-25W...and from 05N-10N between 42W-50W. ...DISCUSSION... GULF OF MEXICO... As mentioned above...a cold front extends from the Florida Big Bend region SW to 26N90W to 20N95W then stationary across inland portions of east-central Mexico. The front is supported aloft by an upper level trough progressing E-SE over the Arklatex region and portions of the NW Gulf this evening. Most convection... scattered showers and isolated tstms...are occurring across central portions of the basin between 85W-92W...and elsewhere within 120 nm either side of the front. The front is expected to drift SE through the next couple of days and gradually become diffuse by Wednesday night. Fresh to strong N-NE winds will prevail through early Wednesday and then weaken slightly into moderate to occasional fresh through early Thursday. Surface ridging is expected to remain in place across the SE CONUS the remainder of the week. CARIBBEAN SEA... An upper level anticyclone is centered over the western Caribbean near 17N81W and is providing mostly dry air aloft between 70W-83W. Isolated to scattered showers and isolated tstms are occurring N of 13N across inland portions of Central America and the Yucatan peninsula. Otherwise...the tropical wave along 77W continues to remain rather benign under the eastern periphery of the ridging. Farther east...upper level troughing dips southward from the SW North Atlc over portions of the NE Caribbean with the base of the trough noted near 17N68W. Upper level divergence along with low- level moisture convergence within fresh to occasional strong E-SE winds are generating widely scattered showers and isolated tstms NE of a line from The Grenadines to the coast of south-central Hispaniola near 18N70W. Elsewhere moderate to fresh trades prevail and are expected to persist through early Wednesday. ...HISPANIOLA... An upper level trough axis extends from east of the Bahamas near 24N73W to a base near 17N68W. Divergence aloft is interacting with local sea breeze dynamics to generate isolated showers and tstms across the eastern half of the island this evening. Looking ahead...a tropical wave will move across Hispaniola by Wednesday and bring additional potential for showers and tstms. ATLANTIC OCEAN... The special features cold front extends across far NW portions of the SW North Atlc from 32N79W to 31N81W. Scattered showers and isolated tstms are occurring N of 29N W of 77W. Farther east...an upper level trough axis extends along 72W and supports a surface trough from 24N71W to 32N70W. Scattered showers and tstms are focused to the E of the boundary occurring N of 22N between 63W- 71W. The remainder of the central and eastern Atlc are under the influence of a surface ridge anchored by a 1031 mb high centered near 34N37W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN