000 AXNT20 KNHC 150005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Sat Oct 14 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...SPECIAL FEATURES... Hurricane Ophelia is centered near 35.9N 23.7W at 14/2100 UTC or about 200 nm SE of the Azores, moving NE at 24 kt. Estimated minimum central pressure is 960 mb. Maximum sustained winds are 100 kt with gusts to 120 kt. Numerous moderate convection is from 34N-38N between 21W-25W. The core of Ophelia will pass to the south and southeast of the Azores tonight. It is expected to be a powerful extratropical cyclone with hurricane force winds as it approaches Ireland. See the latest Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. A cold front will move off the coast of Texas Sunday night, reach from the Florida Big Bend to 23N94W to the Bay of Campeche late Mon, and then stall from Tampa Bay to 25N91W to 18N93W late Tue night. Meanwhile a trough over the south central Gulf, on the northern extent of a tropical wave, will drift into the SW Gulf ahead of the front through Mon. The combination of a slightly tighter pressure gradient along with cooler and drier air associated with the front will allow winds funneling along the coast of Mexico to reach minimal gale force from Tampico to Veracruz Monday through late Tuesday, with seas reaching 8 to 13 ft. ...TROPICAL WAVES... A tropical wave is in the central Atlc with axis extending from 13N35W to 02N35W, moving W at 20 kt. The wave is in a region of strong vertical shear N of 10N. The wave lies underneath upper level diffluent flow that along with shallow moisture support isolated showers from 10N-14N between 32W-40W. A tropical wave is in the central Atlc with axis extending from 15N44W to 04N46W and is expected to move at 10 kt within the next 24 hours. The wave was introduced based on satellite imagery and the tropical waves diagnostic tool. The wave is in a region of strong vertical shear. However, the CIRA LPW imagery show very high concentration of moisture in the wave environment that along with middle to upper level diffluence support scattered heavy showers from 11N-14N between 40W-48W. A tropical wave is in the E Caribbean with axis extending from 21N62W to 11N64W, moving W at 15 kt. The wave is mainly in a low to moderate vertical shear environment and CIRA LPW show the northern portion of the wave is in a region of abundant moisture at the lower levels. Upper level diffluent flow supports numerous showers and squalls mainly to the east of the wave axis from 16N-19N. This activity is expected to spread over the Leeward Islands and the Virgin Islands today and Sunday. Upper-level winds are expected to remain unfavorable for development during the next couple of days, but the environment could turn a little more favorable for some development early next week when the system begins to move northward and then recurves over the west-central Atlantic Ocean. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 08N13W to 07N16W. The Intertropical Convergence Zone axis extends from 07N16W to 07N26W to 05N35W. The ITCZ then resumes near 05N37W to 06N44W...resuming again near 09N47W to 10N58W. Aside from the convection associated with the tropical waves, scattered moderate/isolated strong convection is from 10N-12N between 50W- 58W. ...DISCUSSION... GULF OF MEXICO... A broad surface trough being supported by a middle level inverted trough is moving across the central Gulf along 27N88W to inland Guatemala. Water vapor imagery show dry air aloft, which is limiting the convection to isolated showers and tstms S of 28N E of 95W. Winds S of 25N are variable gentle to light while N of 25N a slightly tight pressure gradient between the trough and a ridge anchored in the SE CONUS support moderate easterlies. The surface trough will move over the W Gulf through through Sunday night when it will shift E due to a cold front that races along Texas to enter the NW Gulf waters early Monday morning with fresh to strong winds behind it. Gale force winds will develop associated with this front. See special features. CARIBBEAN SEA... A tropical wave moving across Honduras and Nicaragua into the EPAC waters continue to support scattered showers and tstms in the NW Caribbean W of 80W. Similar convection is in the SW basin, which continue to be supported by the eastern extent of the E Pacific monsoon trough. Otherwise, a tropical wave is moving across the E Caribbean with a low pressure associated with it, which is centered near 18N63W. Numerous showers and squalls are mainly to the east of the low center from 16N-19N. Fresh to strong winds are E of the wave axis with the strongest winds being in the NE low quadrant. See tropical waves section. Similar winds are within 120 nm off the coast of Colombia. The wave will move over the central Caribbean by Monday morning. ...HISPANIOLA... Isolated showers and tstms are noted in the southern region of the Island between Dominican Republic and Haiti. Showers are forecast to increase in areal coverage and intensity starting Sunday evening as the wave approaches the central Caribbean by Monday morning. ATLANTIC OCEAN... A surface trough is NE of the Bahamas from 31N73W to 25N76W. Isolated showers are within 30 nm of the trough. Further east, a surface trough extends from 29N57W to 23N62W. Scattered moderate convection is from 21N-30N between 55W-68W. Weak surface ridging is elsewhere. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos