000 AXNT20 KNHC 022313 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 713 PM EDT Wed May 2 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through the coastal sections of Liberia, then continues SW to near 01S20W. The ITCZ stretches from 01S20W to 01S50W. A cluster of moderate to strong convection is noted from the Equator to the coast of W Africa between 07W and 10W. Similar convection is also noted S of the ITCZ axis over NE Brazil. ...DISCUSSION... GULF OF MEXICO... A ridge, with axis across the northern Gulf states, dominates the Gulf region producing moderate to fresh E to SE winds across the basin. Buoys and recent altimeter data indicate seas of 4 to 5 ft seas across most of the area. No significant shower or thunderstorms activity is noted. The pressure gradient will tighten slightly tonight over the coast of Texas, between the ridge to the east and a trough over the Southern Plains. This will allow fresh to strong SE return flow to set up overnight, but diminish through the early morning as the trough lifts out. Meanwhile, a thermal trough will develop over the northwest coast of Yucatan, a normal occurrence this time of year, and drift westward. A surge of fresh to occasionally strong NE to E winds will accompany this trough before dissipating over the SW Gulf later in the morning. This pattern will repeat each evening through the period. Fresh to strong NE winds are also expected across the Straits of Florida and the SE Gulf, particularly during the evening hours through Fri. CARIBBEAN SEA... Persistent high pressure north of the area is supporting fresh to strong trade winds across the south-central Caribbean with seas of 8-9 ft. The most recent scatterometer pass confirmed the persence of these winds. Moderate to locally fresh trades are noted elsewhere. Expect increasing winds and building seas across the waters E of the Lesser Antilles first, then across the eastern Caribbean Thu night into Fri due to the pressure gradient between high pressure located E of Bermuda near 32N58W and a well defined surface trough moving across the Bahamas. This weather pattern will keep relatively low winds of 15 to 20 kt off the coast of Colombia, and 10 to 15 kt elsewhere over the western Caribbean. Moisture will remain high across east and central Cuba tonight and Thu while drifting eastward across Hispaniola, keeping the likelihood of scattered to numerous showers and tstms. This will be associated with a cold core mid/upper-level low drifting southward from the Bahamas across eastern and central Cuba to the north central Caribbean. This unstable weather pattern could persist the remainder of the work-week over the eastern half of Cuba and parts of Hispaniola as the low meanders over the same area. Lightning data currently indicate very active weather in the form of scattered to numerous tstms over eastern Cuba, particularly E of Camaguey. ATLANTIC OCEAN... A stationary front extends from 31N56W to 26N65W to the central Bahamas near 23N77W. A surface trough stretches from this point to near the Cayman Islands. A large area of multi-layer clouds with embedded showers and tstms is noted along the frontal boundary affecting mainly the central and SE Bahamas. The convective activity is most concentrated S of the front between 70W and 77W. The most recent scatterometer pass showed fresh to strong winds NE winds within about 180 nm north of this frontal boundary and east of the Bahamas. These winds are the result of the pressure gradient between a 1028 mb high pressure center located near 32N72W and the front. This pattern is also supporting fresh to strong winds across the Straits of Florida, forecast to persist tonight through Thu night with building seas of up to 10 or 11 ft. A sharp upper-level trough reaches from the north central Atlantic, across Bermuda, to the waters north of the northern Bahamas. A cold-core mid/upper low will become cutoff from the trough Thu and drift across the central Bahamas to eastern Cuba. An associated surface trough will develop N of Puerto Rico Thu morning. Active weather spawned by the instability of the cold-core low along with abundant moisture drawn northward in a fresh to strong SE wind flow will accompany the surface trough as it moves W through the Bahamas by late Fri and into the Florida peninsula Sat. Showers and thunderstorms will be possible across South Florida this weekend as well as over western Cuba. Fresh to strong NE winds are expected ahead of the trough, and fresh to strong SE winds will follow the trough, impacting mainly the waters S of 27N-28N and W of 65W. The remainder of the Atlantic is under the influence of a 1029 mb high pressure located over the Azores. For additional information please visit http://www.hurricanes.gov/marine $$ GR/EC