000 AXNT20 KNHC 101159 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 659 AM EST SAT DEC 10 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 0600 UTC surface analysis and satellite imagery through 1145 UTC. ...SPECIAL FEATURES... ...Gulf of Mexico Gale Warning... A strong ridge is across the Gulf of Mexico and inland E Mexico being anchored by a 1037 mb high over W Kentucky near 37N87W. The ridge builds behind a cold front in the SW N Atlc that become stationary NE of the northern Bahamas to the Straits of Florida to NW Cuba to the northern Yucatan Peninsula near 20N90W. A strong pressure gradient between the ridge and low pressure associated with the front a surface trough in the Bay of Campeche is producing NW gale force winds S of 21N W of 95W. This is generating a large area of high seas from 13 to 19 ft. The ridge is forecast to shift eastward today, thus decreasing the pressure gradient in the Gulf and the gale winds, which are expected to continue through tonight. Please read the High Seas Forecast product under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across the African Continent reaching the Atlantic Ocean near 05N10W and continuing to 05N13W. The ITCZ begins near 05N14W and continue along 03N31W to 03N51W. A surface trough extends from 05N-10N along 35W. Active convection continues along the ITCZ, where scattered moderate to strong is observed from 03N-10N between 10W and 50W. ...DISCUSSION... GULF OF MEXICO... The main concern for the Gulf continue to be a gale warning over the SW basin. A strong ridge across the Gulf of Mexico and inland E Mexico being anchored by a 1037 mb high over W Kentucky near 37N87W builds behind a cold front in the SW N Atlc that become stationary NE of the northern Bahamas to the Straits of Florida to NW Cuba to the northern Yucatan Peninsula near 20N90W. Strong pressure gradient between the ridge and low pressure associated with the front a surface trough in the Bay of Campeche is producing NW gale force winds S of 21N W of 95W. This is generating a large area of high seas from 13 to 19 ft. Gale force NW winds are expected to continue through tonight. Please refer to special features for further details. Broken to overcast clouds along with scattered to isolated showers are S of 27N E of 90W and in the SW Gulf S of 22N where tstms have developed. Fresh to strong NE winds are from 22N to 26N W of 81W. The stationary front will weaken today and start dissipating tonight. CARIBBEAN SEA... A broad upper ridge prevails over the basin with strong dry air subsidence supporting fair weather over the NW Caribbean. Over the central basin, a surface trough supported by a middle level inverted trough extends from 17N73W to 10N75W. This surface trough is under a upper level diffluent environment that supports scattered showers S of Hispaniola between 68W and 76W. In the SW Caribbean, the monsoon trough crossing Panama all the way to N Colombia support scattered heavy showers and tstms S of 12N W of 77W. Fresh to locally strong NE to E winds are occurring from 11N to 16N between 65W and 77W. The trough will continue west across the basin and enter Central America early Sun. Moderate to fresh NE trades prevail across the remainder of the basin, except fresh NE winds in the Yucatan Channel near an approaching stationary front. Fresh to occasional strong trades are expected across the south-central Caribbean mainly north of Colombia through late today with trades increasing slightly through the remainder of the weekend as the strong ridge affecting the Gulf of Mexico shifts eastward into the western Atlantic. The stationary front will meander across the Yucatan Channel, with associated conditions across the Gulf spreading modestly into NW portions. ...HISPANIOLA... Fair weather prevails across the island due to strong subsidence of dry air. A modest increase in low level moisture will spread westward across the area today and should lead to passing tradewind showers across the area. Generally fair conditions are expected through the rest of the weekend. ATLANTIC OCEAN... A cold front extends across the western Atlantic from 31N60W to 26N73W where it becomes stationary through the NW Bahamas to northwestern Cuba to the N Yucatan Peninsula. Broken to overcast cloudiness and isolated showers are observed west of the front. Ahead of this front, a surface trough extends from 28N50W to 26N65W to 23N75W. The remainder of the basin, is dominated by a surface ridge anchored by a 1025 mb high centered near 35N27W. Expect the cold front in the west Atlantic to continue moving east of the Bahamas while it drifts slightly SE across the Bahamas. As the surface ridge behind this cold front begins to shift eastward into the Atlantic overnight and Sat, look for increasing NE winds and building seas behind the cold front. Little change is expected elsewhere. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos