000 AXNT20 KNHC 231803 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 103 PM EST Thu Nov 23 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... A 1011 mb low is centered near 28N83W with a cold front extending SW from the low to the NW tip of the Yucatan peninsula then to the Bay of Campeche near 19N91W. Strong to gale force northwesterly winds are occurring S of 20N W of 94W and expected to persist through early this evening. Thereafter winds will diminish slightly and remain generally fresh to strong across the basin west of the cold front through tonight as the low moves NE into the SW North Atlc region. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. A 1008 mb low is centered near 31N64W with the associated cold front extending S-SW to near 27N67W. The existing pressure gradient remains strong within the NE and E quadrants of the low generating near gale to gale force S-SW winds N of 30N between 60W and 62W. These conditions will persist through tonight. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 10N14W to 06N23W. The Intertropical Convergence Zone extends from 06N23W to 06N40W to 07N53W. A surface trough is analyzed W of the ITCZ from 13N54W to 06N58W. Scattered heavy showers and isolated tstms are from 01N-10N E of 39W. ...DISCUSSION... GULF OF MEXICO... An elongated middle to upper level trough extends from the Great Lakes SW across Alabama to a base beyond the Bay of Campeche. This troughing supports the Special Features low analyzed across the NE Gulf and resulting strong to gale force winds west of the front in the SW basin. The low will be quick to move NE into the SW North Atlc region tonight as the front continues across the Florida peninsula and SE Gulf waters, clearing east of the basin by Saturday. Until then, northerly winds are expected as high pressure will influence much of the basin through the weekend. CARIBBEAN SEA... A surface trough extends from central Cuba near 22N80W to 16N82W to Costa Rica coastal waters near 09N83W with isolated showers and tstms within 120 nm either side of the trough axis N of 14N. The eastern extension of the monsoon trough and diffluence aloft enhance this convection to scattered moderate with embedded tstms S of 14N between 74W and 83W. Another surface trough is across the the NE Caribbean extending from 19N64W SE to the Windward Islands near 14N61W. This trough is underneath an upper ridge that covers the central and eastern basin. Shallow moisture in that region of the Caribbean may allow for the development of isolated showers in the vicinity of the boundary. Otherwise, mainly gentle to moderate trades are occurring E of 80W. Little change is expected through Sunday night. ...HISPANIOLA... Clear skies and fair weather reign across the Island underneath a middle to upper level ridge and very dry conditions aloft. These conditions will deteriorate Friday night as the surface trough currently over the NE Caribbean moves west across the Island supporting the development of isolated to scattered showers during the weekend. ATLANTIC OCEAN... A warm front extends from 31N78W SW to a 1011 mb low in the NE Gulf of Mexico and supports scattered heavy showers and tstms over the far NW waters of the basin N of 27N W of 77W. A surface trough traversing central Cuba support similar convection in the Great Bahama Bank between 77W and 80W. A cold front enters the SW North Atlc region near 31N64W and extends to 27N67W. While the front remains relatively benign... the SW North Atlc 1008 mb Special Feature low centered near 31N64W is supported aloft by a mid-level shortwave and continues to generate scattered showers N of 25N between 56W-62W. Farther east, a weakening cold front slices across northern portions of the discussion area from 30N30W W-SW to 27N40W to 27N46W where it becomes stationary along to 57W. Lastly, a weak 1013 mb low is centered near 19N45W with a surface trough analyzed SW from the low to 17N49W. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos