000 AXNT20 KNHC 092334 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 634 PM EST Thu Mar 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 2330 UTC. ...SPECIAL FEATURES... ...Caribbean Gale Warning... The strong pressure gradient generated between 1029 mb high centered near 30N52W and lower pressure analyzed across northwestern South America will support near-gale to gale-force northeast to east winds from 11N to 13N between 73W and 76W tonight. These winds will diminish to near gale force and strong by Friday morning. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough axis extends from the African coast near 11N15W to 04N19W. The Intertropical Convergence Zone extends from 04N19W Brazil coastal waters near 01N50W. Scattered moderate/isolated strong convection is from 01S to 03N west of 18W. ...DISCUSSION... GULF OF MEXICO... High pressure dominates across the basin being anchored by a 1022 mb high near 28N85W. The exception is a surface trough in the SW Gulf extending from 24N95W to the Bay of Campeche near 19N95W. Scattered showers and isolated tstms are associated with the trough N of 20N W of 93W. The current overall pressure gradient allows for moderate E to SE flow, except locally fresh winds in the SW basin due to the convection associated with the surface trough. A large area of high pressure will build southward over much of the basin through Friday. A cold front may move into the northeast Gulf area on Saturday morning. CARIBBEAN SEA... Near-gale to gale-force winds will develop tonight over a portion of the south-central and southwest Caribbean Sea associated with strong high pressure north of the area. See the Special Features section above for additional details. A shear line continues in the NE Caribbean extending from the Leeward Islands near 16N61W to 14N70W with isolated showers within 60 nm either side of it. The shear line is forecast to gradually dissipate through Friday, however a tight pressure gradient over the basin will continue to support fresh to strong northeast to east trades over much of the central and eastern portions of the sea through Friday before diminishing to mainly fresh winds. CIRA LPW imagery show abundant shallow moisture moving across Honduras and Nicaragua as well as adjacent waters, which supports scattered to isolated showers. Showers are also moving across Jamaica. Little change is expected during the next 48 hours. ...HISPANIOLA... Low-level moisture advecting westward in fresh trade wind flow will continue to produce isolated showers over much of the interior of the island and waters adjacent to the northeast coast of the island through early Sunday. The combination of daytime heating and the low-level moisture should allow for increasing instability to promote scattered showers over the interior of the island and southern adjacent waters Friday and Saturday. ATLANTIC OCEAN... The tail of a cold front to the north stalls over the northwest portion of the area from 31N72W to 29N79W with isolated showers within 30 nm either side of the boundary. A 1029 mb high center is analyzed near 30N52W. Farther to the east, a cold front extends from near 30N28W to 18N40W where it transitions to a dissipating cold front to 17N50W. It then becomes a dissipating stationary to east of Guadeloupe. Scattered showers and isolated thunderstorms are present north of 25N between 27W and 33W. Strong high pressure is west of the cold front to near 71W. The stationary front over the northwest portion of the area will dissipate through early Friday. The second cold front over the central and eastern Atlantic will continue moving east while weakening through Saturday. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos