000 AXNT20 KNHC 162336 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 636 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic to the coast of Sierra Leone near 08N13W where it transitions to the ITCZ. The ITCZ continues into the Atlantic along 08N20W to 10N30W to 08N50W to 09N60W. Scattered moderate isolated strong convection is noted from 3.5N to 8N between 23W and 30W. Similar convection is within 120 nm N of the ITCZ axis between 40W and 55W. ...DISCUSSION... ...GULF OF MEXICO... A dry and stable airmass remains in place across most of the basin in the wake of a front currently moving across eastern Cuba and the Caribbean Sea. Abundant cloudiness with patches of mainly light rain are observed along the coast of Mexico roughly between Tampico and Veracruz. Light to gentle winds are noted over the western Gulf under the influence of a 1019 mb high pressure located near 24N96W. 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 E of 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. Moderate to fresh southerly return flow is expected ahead of the front tonight through Friday. Gale conditions are possible over the far southwest Gulf behind the front Saturday and Sunday. ...CARIBBEAN SEA... A few showers and isolated thunderstorms are active along a cold front reaching from Camaguey, Cuba to the Gulf of Honduras. The front will reach from the Windward Passage to the Honduras/ Nicaragua border this evening and stall over Hispaniola to near Cabo Gracias a Dios, Nicaragua on Thursday, then gradually become diffuse over the Caribbean waters through the weekend. Moderate to fresh northerly winds are noted behind the front based on buoy observations. Farther south, a developing area of low pressure remains in place over the southwest Caribbean, near 13N80W. A trough is analyzed from the low center northward to near 17N78W. Scattered moderate convection is noted in a broad area from 12N to 16N between 76W and 82W. A surge of moist southwest flow out of the eastern Pacific has been sustaining this gyre for the past several days. This system has changed little in organization since yesterday, and recent satellite data indicate that the associated winds are light. However, environmental conditions are expected to be conducive for slow development during the next several days, and a tropical depression is likely to form late this week or over the weekend while the low moves slowly and erratically. The latest Tropical Weather Outlook gives this broad low pressure area a high change of tropical cyclone formation through 5 days. Farther east, a well defined surface trough continues to move west across the eastern Caribbean. This trough is forecast to reach the central Caribbean by early Friday, then stall as it moves toward the southwest Gulf Saturday. Upper diffluence, associated with an anticyclone located over the eastern Caribbean near 15N65W, is helping to induce scattered showers and thunderstorms just E of the Windward Islands. This convective activity is mainly affecting the area from 10N to 15N between 55W and 60W. ...HISPANIOLA... A diffluent pattern 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 Hispaniola. On Thursday, the combination of a cold front approaching from the west and a surface trough nearing Dominican Republic will serve as the focus for additional showers and a few thunderstorms through the weekend, as the frontal boundary likely remains nearly stationary over the island. Given persistent high amounts of deep layer moisture, locally heavy rainfall is possible from late Thursday through the weekend. ...ATLANTIC OCEAN... A broad upper-level trough extending across the Eastern Seaboard to SE Florida is moving eastward, supporting a cold front that extends from a 1004 mb low pressure near 27N71W to Camaguey, Cuba. This low pressure has developed along the frontal boundary just E of buoy 41047 that shows increasing winds and a pressure value of 1005 mb. Scatterometer data indicate fresh to strong northerly flow within about 120 nm W of the front, mainly S of 29N to the NW 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 morning. The front will continue to move eastward, reaching from 31N64W to Hispaniola on Thursday, and from 31N58W to Hispaniola on Friday. The front will extend from 31N55W to NE Dominican Republic on 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 early Sunday. Farther east, a broad ridge dominates much of the remainder of the east Atlantic anchored by a 1033 mb high located about 180 nm northwest of the Azores. A trough is noted west of the Canary Islands, north of 26N along 25W-26W. This trough is a reflection of an upper-level low and is generating scattered showers and thunderstorms. Winds of 20 to 25 kt are also noted in association with this trough mainly N of 28N. For additional information please visit http://www.hurricanes.gov/marine $$ GR