000 AXNT20 KNHC 092346 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 746 PM EDT Fri Jun 9 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...TROPICAL WAVES... A tropical wave extends from 13N29W to 04N30W. African dust surrounds the wave. Thus, convection is limited, with only isolated to scattered showers near the wave axis. A tropical wave extends from 14N52W to 06N52W. Convection increases where the wave meets the ITCZ. IR satellite imagery reveals an area of moderate to isolated strong convection from 06N-09N between 50W-54W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends across west Africa and enters the Atlantic Ocean through Guinea Bissau to 08N28W. The ITCZ extends from 08N30W to 07N40W to 08N51W to the coast of Guyana at 08N59W. A pair of tropical waves are within the ITCZ/Monsoon trough. Scattered moderate to isolated strong convection can be found from 04N-07N between 10W-20W, and 06N-10N between 21W-25W. ...DISCUSSION... GULF OF MEXICO... Weather conditions remain very humid and unstable across the SE Gulf, the Florida Keys and south Florida, including also western Cuba. As of 2100 UTC, a weakening frontal boundary persists over south Florida and just north of the Florida Keys, while a surface trough extends over the SE Gulf from 24N84W across the Yucatan Peninsula to northern Guatemala near 17N90W. Scattered to numerous showers and thunderstorms are noted in association with the front and trough. An unusually deep longwave trough, currently near the eastern coast of U.S. extending south across the eastern Gulf, continues to support these active weather. Southwesterly flow ahead of the trough continues to advect deep tropical moisture across this area. The main threat from this convective activity will be heavy rain, lightning, and gusty winds. The trough will drift north tonight accompanied by active weather, then it is forecast to dissipate on Saturday. Moisture associated with the front will aslo lift back northward over South Florida, increasing again the likelihood of rain on Saturday. Locally heavy rain will be possible. A weak ridge dominates the remainder of the Gulf region, producing a few clouds and light to gentle winds. CARIBBEAN SEA... As perviously mentioned, western Cuba is also under the influence of the large scale mid-upper level trough now located near the eastern coast of U.S. and the eastern Gulf of Mexico. This weather pattern has brought heavy rain across parts of western Cuba, particularly over the provinces of Mayabeque and Matanzas, where rainfall amounts of 7-8 inches (180-200 mm) in 24 hours were reported by the Cuban Weather Service this morning. Weather conditions are forecast to gradually improve across western Cuba during the upcoming weekend as ridge begins to develop across the region. Abundant mainly mid to upper clouds are noted across the Lesser Antilles on the SE side of an upper-level low spinning near the Virgin Islands. The most recent scatterometer data provide observations of mainly moderate trade winds over the eastern caribbean and parts of the central Caribbean. Winds are light south of 13N west of 77W. Moderate to locally fresh trades are expected across the basin through the upcoming weekend except for fresh to strong trades across the south-central portions of the Caribbean and the Gulf of Honduras starting Saturday. ...HISPANIOLA... Daytime heating, local sea breezes and mountain upslope lifting will combine with available moisture in the region to produce some cloudiness with scattered showers and isolated thuderstorms, particularly during the afternoon and early evening hours. ATLANTIC OCEAN... A pair of tropical waves are moving westward between the coast of Africa and the Lesser Antilles. Please refer to the Tropical Waves section above for details. A third tropical wave appears to be entering the Atlantic Ocean and could be added to the next surface map at 0000 UTC. As of 2100 UTC, a stationary front extends from 31N75W to south Florida. A band of showers and thunderstorms extends from the Straits of Florida across the NW Bahamas and the western Atlantic just ahead of the front forecast to drift north on Saturday before dissipating on Sunday. A weak ridge will build across the western Atlantic through the weekend. High pressure dominates the remainder of the Atlantic, with a 1023 mb high center near 27N55W, and another center of 1021 mb located near 30N26W. For additional information please visit http://www.hurricanes.gov/marine $$ GR