000 AXNT20 KNHC 161805 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 PM EST WED NOV 16 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 1200 UTC surface analysis and satellite imagery through 1800 UTC. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic to the coast of Sierra Leone near 08N113W where it transitions to the ITCZ. The ITCZ continues into the Atlantic to 10N25W then terminates off the coast of Guyana near 08N58W. Scattered moderate convection is noted within 120 nm to the north of the ITCZ between 25W and 30W. Scattered moderate to isolated strong convection is also noted in the western Atlantic within 120 nm north of the ITCZ between 50W and 55W. ...DISCUSSION... ...GULF OF MEXICO... A dry and stable airmass remains in place across the entire basin this morning, in the wake of a frontal passage that swept across the region since early this week. Mid and high level clouds related to the subtropical jet blanket the far southwest Gulf of Mexico, along the coast from Tampico to Veracruz to Ciudad del Carmen. Nearly calm winds persist over the far northwest Gulf, under the influence of high pressure. Moderate to fresh northerly flow is noted over the southeast Gulf however, between the ridge over the northwest and central Gulf, and developing low pressure over the Bahamas. Seas range from 1 to 3 ft over the northern Gulf, and 3 to 5 ft over much of the southern Gulf. Looking ahead, the high pressure over the northwest Gulf will shift eastward ahead of a strong cold front expected to sweep across the basin this weekend. Gale conditions are possible over the far southwest Gulf behind the front Saturday and Sunday. ...CARIBBEAN SEA... A few showers and thunderstorms are active along a cold front reaching from central Cuba to the Gulf of Honduras. The front is slowing down, and is expected to stall from northern Haiti to eastern Honduras Thursday, then gradually become diffuse through the weekend. Northerly winds have increased to 15 to 20 kt recently at Buoy 42056 in the northwest Caribbean behind the front. Farther south, a developing area of low pressure remains in place over the southwest Caribbean, near 12N80W. Scattered showers and thunderstorms are noted in a broad area within 270 nm in the northeast semicircle of the low pressure. A surge of moist southwest flow out of the eastern Pacific has been sustaining this gyre for the past several days. Further development is expected over the next couple of days as the low pressure remains over the southwest Caribbean, and tropical cyclone development cannot be ruled out through the next five days. Farther east, a well defined surface trough continues to move west, reaching the central Caribbean by early Friday, then stalling as it moves toward the southwest Gulf Saturday. ...HISPANIOLA... Divergent flow aloft between a broad upper trough moving off Florida into the northern Bahamas, and an upper anticyclone over the eastern Caribbean Sea is enhancing scattered showers and a few thunderstorms across northern Haiti currently. While this activity is weakening, a few showers and thunderstorm may develop over higher terrain inland this afternoon. A cold front will move across eastern Cuba and the Windward Passage through Thursday, eventually stalling over northern Haiti by Friday. This will serve as the focus for additional showers and a few thunderstorms through the weekend over much of Haiti and western Dominican Republic. Given persistent high amounts of deep layer moisture, locally heavy rainfall is possible from late Thursday through the weekend. ...ATLANTIC OCEAN... A broad upper trough reaching from off New England to east central Florida is moving eastward, supporting a cold front at the surface currently reaching 31N68W to central Cuba. The associated comma cloud pattern suggests a surface low may starting to form east of the northern Bahamas. Further evidence is provided by a scatterometer pass from 15 UTC indicating a surface is indeed starting to form along the front near 26N74W. The scatterometer also indicated fresh northerly flow within 150 nm to the north of the front, reaching across much of the central Bahamas. Scattered showers and thunderstorms are evident ahead of the front near the Turks and Caicos Islands. The low pressure is expected to move rapidly to the northeast toward Bermuda through early Thursday. The front will continue to move eastward, reaching from 31N55W to northern Haiti by early Saturday, before stalling and weakening from 31N50W to northeast Dominican Republic by early Sunday. Meanwhile a stronger cold front is expected to move into the waters off northeast Florida by Sunday. Farther east, a broad ridge dominates much of the remainder of the east Atlantic anchored by a 1034 mb high about 300 nm northwest of the Azores. A trough is noted west of the Cabo Verde Islands, north of 25N along 23W. This is supporting scattered showers and thunderstorms and winds of 20 to 25 kt within 180 nm to the north of the trough. For additional information please visit http://www.hurricanes.gov/marine $$ CHRISTENSEN