000 AXNT20 KNHC 271156 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 756 AM EDT Sat Oct 27 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. ...SPECIAL FEATURES... Subtropical Storm Oscar centered near 27.3N 47.0W at 27/0900 UTC or 970 nm ESE of Bermuda moving WNW at 10 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. A westward motion with an increase in forward speed is expected today and tonight, followed by a reduction in speed on Sunday. A turn toward the north-northwest is forecast on Monday. Additional strengthening is forecast during the next several days, and Oscar is expected to make a transition to a tropical storm on Sunday. Oscar could then become a hurricane by early next week. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC for more details. ...TROPICAL WAVES... An Atlantic tropical wave has an axis extending along 47W from 02N-14N, moving west at 10-15 kt. Scattered showers are noted along the northern portion of the wave mainly north of 10N. TPW satellite imagery shows this wave to be embedded in a region of deep layer moisture. This feature also is well depicted in tropical wave model diagnostic and initial 700 mb model fields. ...MONSOON TROUGH/ITCZ... The monsoon trough heads WSW from the coast of Guinea on the African coast near 11N14W to 08N17W. The ITCZ continues from 08N17W to 05N26W to 04N34W to 07N45W. Scattered moderate and isolated strong convection is seen from 02N to 09N between 16W and 40W. GULF OF MEXICO... A cold front curves SW from 26N82W to 23N91W, then becomes stationary to 21N97W. Scattered moderate and convection is noted along and up to 120 nm N of the front to the W of 87W. High pressure building SE from the southern plains of the United States will eventually push the front to the SE of the Gulf by Sun morning. A second and much weaker cold front will clip the northeastern Gulf of Mexico Mon and Tue, followed by high pressure building SW. CARIBBEAN SEA... Broad surface ridging extends SSW from a 1026 mb Atlantic Ocean high centered near 35N62W toward the Caribbean. Broad mid to upper level anticyclonic wind flow spans the entire area. Gentle to moderate trade winds will prevail across the Caribbean Sea through Saturday. A frontal boundary currently over the Gulf of Mexico will eventually push across the Yucatan Channel on Saturday night and Sunday. Fresh to locally strong trade winds are expected over the south central Caribbean Sea on Sat night and Sun, before low pres moving over the western Atlc from the eastern United states weakens the ridge N of the Caribbean Mon and Tue. ATLANTIC OCEAN... Convergent S to SSW low-level winds to the E of a cold front over Florida are generating scattered moderate and isolated strong convection from 23N to 28N between 72W and 75W. A surface trough curves W from weak 1012 mb low pressure centered just NW of the Canary Islands near 30N19W to 27N25W to 28N30W. This system has no significant convection currently associated with it. The cold front extends across the western Atlantic with scattered showers. It will stall and weaken from around 31N70W to central Cuba on Sunday. A second but weaker cold front will move E of north Florida Mon then slowly sink S Tue and stall over the northern Bahamas by early next week. Elsewhere, high pressure ridging over the Atlc is weakened by low pres moving over the western Atlc from the SE United States, Sub T.S. Oscar and low pres near the Canary Islands. Accordingly, the weakened ridge is generally supporting light to moderate trades over the tropical Atlc from the ITCZ to 15N between 25W and the Windward Islands. For additional information please visit http://www.hurricanes.gov/marine $$ McElroy/ERA