000 AXNT20 KNHC 040557 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 157 AM EDT Thu May 4 2017 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 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...SPECIAL FEATURE... A strong cold front is entering the NW Gulf of Mexico early this morning, which will lead to the development of gale-force winds near 1500 UTC today. Gale conditions are expected south of 24N west of 96W as the front extends from the Florida Panhandle SW to near Tampico, Mexico. High pressure building over the central plains and over Mexico behind the front will weaken thereafter allowing the gale winds to subside by Thursday night. Please refer to the High Seas Forecast product under AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough crosses the western African coast near 10N14W and extends to 06N16W to 04N20W where the ITCZ begins and continues along 03N36W to the coast of Brazil near 00N48W. Scattered moderate convection is from 01S to 07N west of 20W. ...DISCUSSION... GULF OF MEXICO... A middle to upper level trough across the central plains supports a strong cold front that is entering the NW Gulf waters along 29N94W to 28N96W. A warm front is ahead of the cold front extending from 28N88W to 30N92W. Water vapor and CIRA LPW imagery show abundant moisture in the north-central basin where upper level winds diverge to support heavy showers and severe tstms N of 27N between 87W and 97W. Fresh to near gale southeasterly winds are ahead and in the vicinity of this area of strong convection. In addition, dense fog is being reported N of 27N W of 90W with visibility less than 3 miles. Gale force winds are forecast to develop in the SW basin later this morning. Please see the special features section for more details. The front will bring showers across the central and NE basin Thursday and over central and southern Florida Friday. The cold front will exit the straits of Florida early Saturday morning. CARIBBEAN SEA... The Caribbean Sea is very quiet this morning. Shallow convection is being observed over northern and western Hispaniola being supported by a middle level diffluent environment just over the Island. Scattered to isolated showers are also being reported in the Leeward Islands supported by an upper level trough and shallow moisture being advected from the tropical Atlc. Latest scatterometer data show mainly moderate trades across the region, except for fresh winds off the coast of northern Colombia S of 14N and in the Gulf of Honduras. Water vapor imagery show dry air subsidence elsewhere, thus supporting fair weather. Showers will continue across Hispaniola today and are forecast for the far NW Caribbean starting Friday as a cold front moves across southern Florida. The front is forecast to enter NW Caribbean waters early Saturday morning. ...HISPANIOLA... Shallow convection is being observed over northern and western Hispaniola being supported by a middle level diffluent environment just over the Island. These showers will continue through tonight. ATLANTIC OCEAN... With little support aloft, the tail of a stationary front starts to dissipate this morning from 30N73W to 28N77W. Southeast of this front, a surface trough races across the western Bahamas supporting scattered to isolated showers. Broad surface high pressure dominates the remainder SW N Atlc and central Atlc waters and provides stable and fair weather conditions. Otherwise, a broad middle level low north of the area continue to support a cold front from 30N17W to 22N30W to 22N42W with possible isolated showers within 90 nm either side of the boundary. A new strong cold front is forecast to come off NE Florida Friday morning and move over the northern and central Bahamas Saturday as it weakens. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos