000 AXNT20 KNHC 082334 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 734 PM EDT Thu Jun 8 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 has emerged from the west coast of Africa. Its axis extends from 15N17W to 06N17W. The north end of the wave is just east of Dakar, Senegal based on surface observations. Convection increases where the wave meets the ITCZ. IR satellite imagery reveals an area of moderate to isolated strong convection from 08N-11N between 17W-21W. The wave shows up pretty well in the TPW product. A 700 mb trough is also noted. A tropical wave extends from 11N44W to 03N45W. African dust surrounds the wave. Thus, convection is limited, with only isolated to scattered showers near the wave axis. Another tropical wave extends from 14N55W to Suriname near 04N55W. The wave is well depicted in the moisture product and the 700 mb streamline analysis. Isolated to scattered showers and thunderstorms are near the southern end of the wave axis. Scattered moderate convection is noted from 07N-10N between 51W-54W. A tropical wave continues to move westward across the Caribbean Sea. Its axis extends from Haiti to near the coast of Colombia at 11N74W. The TPW animation shows a surge of moistened air in association with this wave, but mainly south of 16N. Scattered moderate to isolated strong convection is near the southern end of the wave axis over northern Colombia. This wave is forecast to cross 80W by Friday evening, likely reaching the Atlantic coast of Nicaragua by early Saturday morning. ...MONSOON TROUGH/ITCZ... The monsoon trough is inland over W Africa east of 11N15W. The ITCZ is W of a tropical wave and extends from 10N18W to 07N30W to 06N40W to 07N50W to 08N54W. Besides the convection mentioned in the Tropical Waves section, isolated to scattered moderate convection is within about 150 nm south of the ITCZ axis between 28W-33W. ...DISCUSSION... GULF OF MEXICO... As of 2100 UTC, a 1006 mb low pressure is centered over central Florida near 28N81W. A cold front extends SW from the low to the SE Gulf near 23N86W. This low pressure system and associated trough/cold front brought heavy rain to South Florida during the previous two or three days. The Mosaic Doppler Radar from the SE U.S. and lightning data are still showing bands of showers with embedded thunderstoms across the Florida Peninsula, but less intense than yesterday. Convection is now more concentrated across the Straits of Florida and western Cuba. The cold front will drift SE over the SE Gulf before stalling and dissipating over the next 36-48 hours. An unusually deep longwave trough over the Eastern CONUS and the central Gulf of Mexico supports the low/cold front. Weak high pressure follows the front and will dominate most of the Gulf region tonight and Friday. A trough, currently located over the western Caribbean and its associated convective activity is expected to drift NW into the SE Gulf of Mexico and the Yucatan Peninsula late Fri into Saturday. CARIBBEAN SEA... A tropical wave is along 74W. Please, refer to the Tropical Waves Section for more details. A surface trough extends from the westernmost tip of Cuba to the Gulf of Honduras. A recent ASCAT pass indicates the wind shift related to this trough, that will continue to generate scattered showers and thunderstorms along and to the east side of the trough on Friday. Locally heavy rain could occur over parts of western Cuba tonight and Friday. This trough is forecast to drift NW, moving into the Gulf of Mexico late Fri into Saturday. The TPW animation shows abundant moisture across the NW Caribbean and western Cuba in association with the trough. The most recent scatterometer data provide observations of mainly moderate to locally fresh trade winds over the eastern and central Caribbean. Moderate to locally fresh southerly winds are aslo noted across the NW Caribbean, east of the above mentioned surface trough. Fresh to strong trade winds are expected over the south- central Caribbean and the Gulf of Honduras starting Saturday night. ...HISPANIOLA... Daytime heating, local sea breezes and mountain upslope lifting will combined with available moisture to produce some cloudiness with scattered showers and isolated thunderstorms, particularly during the afternoon and early evening hours. ATLANTIC OCEAN... Three tropical waves are moving westward between the coast of Africa and the Lesser Antilles. Please refer to the Tropical Waves section above for details. As of 2100 UTC, a cold front extends from 31N77W to the low pressure located over central 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 cold front, forecast to drift SE reaching from 31N74W to central Florida by Friday morning. Fresh to strong SW winds and scattered to numerous showers and thunderstorms will prevail SE of the front. The remainder of the Atlantic is under the infuence of a ridge, anchored by a 1022 mb high pressure located near 29N34W. A new high pressure center is forecast to develop along the ridge axis near 28N55W in about 24 hours. For additional information please visit http://www.hurricanes.gov/marine $$ GR