000 AXNT20 KNHC 270508 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 108 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 0000 UTC surface analysis and satellite imagery through 0400 UTC. ...SPECIAL FEATURES... Newly formed Subtropical Storm Oscar is centered near 26.7N 45.7W at 27/0300 UTC, with winds of 40 kt gusting to 50 kt. Oscar has a central pressure of 1005 mb and is moving NNW at 8 kt. Oscar is interacting with a broad upper-level low to the SW and as a result a broad arc of scattered moderate and isolated strong convection is found between 120 nm and 360 nm of 24N46W, except within the southern quadrant. A turn toward the W and WSW at a faster forward speed is expected on Saturday, with this motion continuing through Sunday night. Gradual strengthening is forecast during the next couple of days, and Oscar could become a tropical storm on Sunday. Please refer to the TROPICAL WEATHER OUTLOOK, MIATWOAT/ABNT20 KNHC, for more details. ...TROPICAL WAVES... An Atlantic tropical wave has an axis extending from 02N47W to 13N45W. Scattered moderate and isolated strong convection is present from 06N to 13N between 41W and 50W. 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 31N81W to just N of Ft Myers Florida near 27N83W to the SW Gulf of Mexico near 23N92W, then continues as a stationary front to the vicinity of Veracruz on the coast of Mexico near 21N97W. Scattered moderate and isolated strong 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 currently beginning to emerge over the western Atlc from Florida will push SE into the NW Bahamas today, then 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 on Wednesday. Otherwise, high pres 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