000 AXNT20 KNHC 302338 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 PM EST FRI DEC 30 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 2315 UTC. ...SPECIAL FEATURES... ...Caribbean Gale Warning... The pressure gradient will tighten this weekend over the Caribbean supporting pulsing gale force winds across the south- central Caribbean mainly from 11N-13N between 73W-76W during the overnight hours. These winds are expected to continue to pulse during the overnight hours through Monday night. Please see the High Seas Forecast product under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across southwest Africa to the coast near 5N9W where the ITCZ begins and continues along 4N13W 4N22W 2N31W to 1N38W. Scattered moderate to isolated strong convection is within 45 nm of 3N between 32W-39W. ...DISCUSSION... GULF OF MEXICO... The broad upper trough is moving over the Canadian Maritimes and into the northwest Atlantic supporting a cold front that at 30/2100 UTC extends from the west Atlantic across the northeast Caribbean becoming a dissipating stationary front over the north coast of the Yucatan Peninsula near 21N88W into the Gulf along 22N94W then south into Mexico near 19N95W. An upper ridge extends from the east Pacific region across southern Mexico and the Gulf waters to near 25N90W. This is advecting tropical moisture across Mexico over the north Gulf and is generating scattered showers north of 27N west of 91W. Low level clouds with possible isolated showers are south of 26N to the front west of 90W. A surface ridge is building over the Gulf in the wake of the front anchored by a pair of 1030 mb highs over the lower Mississippi Valley and east Texas. The front will dissipate tonight. Strong high pressure will support fresh winds over the southeast Gulf and the Straits of Florida tonight and Saturday. The next front will move into the Gulf on Monday. CARIBBEAN SEA... The west Atlantic cold front extends across central Cuba at 30/2100 UTC near 22N79W to 21N83W where it dissipates to the north coast of the Yucatan Peninsula near 21N87W. This portion of the front is transecting an area of dry air, thus no shower activity is noted. An upper ridge remains across the Caribbean with southwest to westerly flow aloft. Easterly trade winds are banking isolated to scattered showers over the southwest Caribbean south of 15N west of 78W to over Central America. Fair weather with possible isolated, low level showers are across the remainder of the Caribbean this evening. The front will move south of the Yucatan Channel tonight before dissipating Saturday. High pressure will move across the west Atlantic supporting strong trade winds across the Caribbean with pulses of gale force winds off the coast of Colombia. Please see the Special Features above. HISPANIOLA... Isolated showers have developed across the island this evening. Showers will increase Saturday with the approach of the frontal boundary from the west. These showers will continue through the remainder of the weekend. ATLANTIC OCEAN... The broad upper trough moving over the Canadian Maritimes and into the northwest Atlantic is supporting a cold front that at 30/2100 UTC extends through 32N65W along 25N72W across the Bahama Islands and over central Cuba into the Caribbean near 22N79W. Scattered showers and isolated thunderstorms are within 90 nm east of the front north of 29N. A surface trough precedes the front extending from 30N64W to the Turks and Caicos near 21N72W with scattered showers within 150 nm east of the trough north of 24N. A surface ridge covers the central Atlantic between 30W-60W anchored by a a 1025 mb high near 31N45W. An upper trough over the east Atlantic is supporting a surface trough that extends through 32N21W to 26N24W. The west Atlantic cold front will reach from 32N56W 23N67W dissipating across east Cuba by Saturday morning then into the central Atlantic by Sunday morning. For additional information please visit http://www.hurricanes.gov/marine $$ PAW