000 AXNT20 KNHC 152348 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 648 PM EST THU DEC 15 2016 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. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 09N13W and continues to 06N16W to 03N20W. The intertropical convergence zone axis extends from 03N20W to 03N36W to 01N50W. Scattered to isolated moderate convection is within 120 nm either side of both the monsoon trough and the ITCZ. ...DISCUSSION... GULF OF MEXICO... A middle to upper level trough in the W Atlantic extends SW across the Florida Peninsula and the E Gulf, thus supporting a cold front extending from 30N70W to S Florida near 25N81W to 23N89W where it stalls and continues W to Veracruz, Mexico near 22N98W. Low to middle level moisture in the SW basin along with upper level diffluence support scattered to isolated showers in the W Bay of Campeche. Water vapor, CIRA LPW and SSMI TPW imagery show dry air across the remainder basin, which is supporting fair weather. Latest scatterometer and surface data show moderate to locally fresh N-NE winds N of the frontal boundary and gentle N-NE flow ahead of it. The cold front will move out of the SE Gulf tonight while the stationary portion of the boundary will weaken and dissipate. Surface ridging and return flow will then dominate the basin through Sunday before sunrise. CARIBBEAN SEA... Diffluent upper level flow over the SW Caribbean along with low to middle level moisture in the region support scattered to isolated showers S of 19N between 76W and 84W, including Jamaica. Shallow moisture is moving across the far E basin supporting passing showers E of 65W, moving across Puerto Rico tonight. Gentle to moderate NE flow covers the NW Caribbean waters ahead of a cold front over the SE Gulf of Mexico. Fresh to strong trades are in the S central waters S of 13N between 74W and 77W. This area of winds will amplify N and across the E Caribbean Friday night through Sunday as a strong surface ridge moves off the NE CONUS to W Atlantic waters. ...HISPANIOLA... Water vapor, SSMI TPW and CIRA LPW imagery show dry stable air over the Island, which is supporting fair weather conditions. Similar weather is forecast for the rest of the weekend. ATLANTIC OCEAN... A cold front is over SW N Atlantic waters extending from a system of low pressure over NW Atlc waters. The front, which is being supported by a middle to upper level trough, is along 30N69W to the northern Bahamas near 26N77W to SE Florida near 25N80W to the SE Gulf of Mexico. Shallow moisture in the vicinity of the front may support isolated showers tonight. A broad surface ridge anchored by a 1032 mb high on the Azores covers the remainder basin, thus supporting stable and fair weather conditions. The front is forecast to move to central Atlantic waters by Friday evening, then will move N of the forecast waters by Sunday morning. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos