000 AXNT20 KNHC 112259 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 559 PM EST SUN DEC 11 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. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across the African Continent entering the Atlantic Ocean through Liberia near 07N11W to 05N18W. The ITCZ axis begins from 05N18W and extends through 04N30W to 06N40W. A surface trough is embedded within the ITCZ extending from 10N42W to 03N43W. Scattered moderate isolated strong convection is N of 02N to the coast of Africa between 05W and 09W. Similar convection is within 75 nm S of axis between 29W and 31W, and from 01N to 03N between 34W and 37W. ...DISCUSSION... GULF OF MEXICO... High pressure located NE of the region extends a ridge across the SE CONUS into the Gulf and much of the Gulf waters into central Mexico, while the remnants of a frontal boundary remains across the SE Gulf stretching from across the Straits of Florida to 23N88W to 21N93W. The most recent scatterometer pass showed the presence of a surface trough across the SW Gulf, extending from near Tampico Mexico to the western Bay of Campeche near 19N95W. Under this weather pattern, fresh to locally strong southerly flow has developed over the NW Gulf while fresh to locally strong easterly winds are noted over the eastern Gulf north of the frontal boundary to about 26N. Multilayered clouds with embedded showers are over the SW Gulf. The high located NE of area will continue to slide eastward with a 1020 mb high pressure developing over the NE Gulf on Monday. This system will persist through Wednesday. The next cold front is forecast to reach the N and NE Gulf wed night followed by another strong high pressure system. This will result in increasing N-NE winds mainly across the N waters on Thursday. Aloft, a trough is over the NW Gulf. Southwesterly flow ahead of the trough dominates the remainder of the Gulf. CARIBBEAN SEA... An area of showers and thunderstorms persists over the SW Caribbean associated with a surface low pressure located near 10N81W. The strongest convection associated with this system is currently over waters, affecting mainly the area from 12N to 15.5N between 79W and 83W. A diffluent pattern aloft is helping to induce this convective activity. Computer model indicates that all this moisture will spread across northern central America and the Gulf of Honduras on Monday and will persist on Tuesday. Locally heavy rain with the potential of flash flooding and mudslides could occur over parts of northern Costa Rica, Nicaragua and Honduras through Monday. Fresh to strong trades are blowing over the south- central Caribbean based on scatterometer data. Moderate to fresh trades are noted across the remainder of the central Caribbean and eastern part of basin while mainly moderate NE winds are observed over the NW Caribbean. These winds will persist over the next couple of days, and are forecast to diminish by Wednesday as high pressure N of area moves eastward and slightly weakens. ...HISPANIOLA... Moisture are expected to diminish on Monday as the inverted trough currently north of the island continues to moves westward. Another patch of moisture will approach from the east on Tuesday. Light showers could occur in the afternoon due to local effects. ATLANTIC OCEAN... A stationary front extends across the western and central Atlantic from 24N80W to 25N63W to 31N46W. Isolated showers are observed within 80 nm to the north of the front affecting portions of South Florida and the Bahamas. A surface trough was analyzed north of Hispaniola extending from 23N69W to 20N70W. Scattered showers are observed along this trough. A surface ridge extends across the remainder of the basin anchored by a 1025 mb high centered near 29N36W and a 1026 mb high near 33N25W. Expect for the stationary front to start weakening during the next 24 hours. A surface ridge will build in the western Atlantic. Little change is expected elsewhere. For additional information please visit http://www.hurricanes.gov/marine $$ GR