000 AXNT20 KNHC 041144 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 744 AM EDT Fri May 4 2018 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 0600 UTC surface analysis and satellite imagery through 1145 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from 10N14W to 00N34W. The intertropical convergence zone continues from 00N34W to 01S48W. Scattered moderate convection is ongoing from 04S to 04N between 24W and 30W. ...DISCUSSION... GULF OF MEXICO... A surface ridge extends east to west from the western Atlantic along the northern Gulf coast to Texas. Strong peak winds reported by NOAA buoy observations in the Florida Keys are evidence of moderate to fresh easterly winds persisting across the Straits of Florida, between the ridge to the north, a weak trough over the far southeast Gulf, and a more developed trough to the east of the area. Seas are likely reaching 8 ft in the Straits accordingly, reaching as far west as the approaches to the Yucatan Channel, up to a latitude of about 25N. Convergence of the fresh to strong easterly flow out of the Bahamas is supporting scattered showers across the Florida Straits, as noted in regional radar. Fresh SE return flow and seas to 6 ft are noted over the far northwest Gulf, between the ridge and lower pressure over south Texas. A couple of platforms in the Texas coastal waters are report light to moderate fog in the moist SE flow, but widespread fog or significant restriction to visibility is not anticipated through the day. Farther south, a daily thermal low will develop inland inside the Yucatan Peninsula, causing surges of fresh to occasionally strong NE to E winds as the low strengthens and weakens over the coming days. For the forecast, winds over the southeast Gulf will diminish and back more to the NE through early Sat ahead of the trough moving from the western Atlc across Florida. Scattered showers and thunderstorms will accompany the trough as it moves into the eastern Gulf early Sun before stalling and weakening. The ridge will weaken as well and high pressure will shift west through the lower Mississippi Valley, allowing moderate northerly flow and 2ft to 4 ft seas through mid week. CARIBBEAN SEA... A surface trough is developing from north of Hispaniola into the north central Caribbean. E to SE winds will increase slightly from the Tropical North Atlantic through the central Caribbean as high pressure builds westward over the Atlantic in the wake of the trough. This is already starting to happen as winds off Colombia have diminished slightly from the last synoptic observations, as they increase through the Windward and Leeward Islands. Scattered thunderstorms are popping up in the Windward Passage as well, on the south side of a prominent mid/upper low centered north of the area, moving slowly to the west. Seas will build over tropical north Atlantic and the eastern Caribbean to 6 to 9 ft through Sun. This pattern will persist through Sun, then start to subside into early next week as the trough moves farther westward and the ridge weakens. Atmospheric instability associated with the mid/upper level low will provide more thunderstorm potential to the north central Caribbean through late Sat. ATLANTIC OCEAN... The main weather maker remains a prominent cold-core, mid/upper level low centered over Great Exuma in the central Bahamas. Divergence of the southeast side of this feature is supporting a broad area of scattered showers and thunderstorms over the southern Bahamas, Turks/Caicos Islands, and north of Hispaniola and Puerto Rico. This is also supporting the development of a amplifying surface trough extending from 28N68W through eastern Haiti and into the north central Caribbean. Strong NE to E winds are ahead of the trough east and across the Bahamas, with seas in excess of 7 ft noted in an altimeter satellite pass at 0950 UTC. Fresh to strong easterly winds are noted between 20N and 28N, closer to the subtropical ridge axis. Buoy and scatterometer data also show strong SE winds off the Leeward Islands in the Atlantic, with buoys showing seas to 9 ft. This is related to ridging building in the wake of the trough. The trough will sharpen and elongate as it moves westward, eventually moving into Florida Sat. Strong to near gale force winds will accompany the trough, as well numerous showers and scattered thunderstorms across the Bahamas through Sat. Scattered thunderstorms are possible across the Bahamas and adjacent waters into Sun as the upper low slowly drifts south-southwestward. Winds and seas will start to diminish Sun through early next week as through lifts northward to off the northeast coast of Florida through Mon, and the ridge weakens, but hold in place along roughly 28N/29N. Farther east, the remainder of the Atlantic is under the influence of a 1028 mb high pressure located near 33N57W. This system is producing moderate to fresh trade winds across the deep tropics, where seas are reaching 6 to 8 ft in NE to E swell. For additional information please visit http://www.hurricanes.gov/marine $$ Manougian