000 AXNT20 KNHC 271727 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 127 PM EDT Sun May 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...SPECIAL FEATURES... The center of Subtropical Storm Alberto as of 27/1500 UTC, is located near 27.1N 84.4W, or about 113 nmi WSW of Tampa, FL, or about 161 nmi SSE of Apalachicola, FL. The estimated minimum central pressure is 994 mb. The maximum sustained wind speeds are 45 knots with gusts to 55 knots. The system is moving N at about 12 kt. Scattered to numerous moderate convection is noted from 21N-31N between 76W-87W affecting the Florida peninsula, Straits and Keys, northern Bahamas and central Cuba. Alberto is expected to become a tropical storm during the next few hours before moving inland over the Florida Panhandle by 28/12Z. The system will weaken rapidly after that. Public Advisories about Subtropical Storm Alberto are being listed under the WMO header WTNT31 KNHC, and under the AWIPS header MIATCPAT1. The Forecast/Advisories about Subtropical Storm Alberto are being listed under the WMO header WTNT21 KNHC, and under the AWIPS header MIATCMAT1. ...TROPICAL WAVES... A tropical wave extends its axis across the eastern Atlantic from 12N25W to 00N26W, moving W at about 10 kt. The wave shows up well in lower level precipitable water imagery. Scattered showers are noted along and the wave axis mainly south of 05N. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Africa near 11N15W to 04N21W. The ITCZ continues west of the tropical wave near 03N28W to the coast of Brazil near 00N48W. Scattered moderate convection is noted within 50 nm on either side of the monsoon trough and ITCZ axes. ...DISCUSSION... GULF OF MEXICO... Please read the Special Features section for information about Subtropical Storm Alberto, currently located over the eastern Gulf. This system is supported at upper levels by a trough that extends along 87W covering the central and east Gulf waters and the Yucatan Channel. Latest scatterometer data depicts fresh to strong winds over the east Gulf near Alberto, moderate to fresh winds over the central Gulf, and gentle to moderate winds over the western Gulf waters. Wave heights across the basin are ranging from 12-15 ft near Alberto's center, 5-8 ft over the central Gulf and 2-3 ft for the western Gulf waters. Expect for winds and seas to decrease following landfall on Monday. CARIBBEAN SEA... Please refer to the Special Features section above, for information about Subtropical Storm Alberto, currently located over the eastern Gulf. An upper-level trough extends from the central Gulf of Mexico, across the Yucatan Channel into the northwest corner of the Caribbean. Scattered moderate convection covers portions of Cuba and adjacent waters due to the proximity of Alberto. This activity is mostly located west of 79W. Another area of scattered to numerous moderate convection is noted south of 12N between 75W-82W affecting Central America and northern Colombia. Scatterometer data depicts moderate to fresh easterly winds across most of the basin except west of 80W, where gentle to moderate southerly winds prevail. Wave heights range between 4-6 ft across the far east and west Caribbean, while 5-7 ft seas will continue between 69W- 74W. The winds and the sea heights will continue to decrease in the western Caribbean, given that Alberto is moving away from the area. High pressure in the central Atlantic will maintain fresh to strong trade winds pulsing in the central Caribbean through the early part of the week. The fastest wind speeds are expected along the coast of Colombia and in the Gulf of Venezuela. ATLANTIC OCEAN... Please read the Special Features section above for information about Subtropical Storm Alberto, currently located over the eastern Gulf. The surface pressure gradient between Subtropical Storm Alberto and the Atlantic surface ridge may support increasing wind speeds to near gale-force in the Florida coastal and offshore waters through tonight. A surface ridge extends across the basin from a 1024 mb high pressure center that is near 31N58W, to a 1029 mb high near 39N25W. Aside from the convection related to Alberto over the west Atlantic west of 75W, the only area with shower activity at this time is east of the Leeward Islands from 16N-19N between 54W-63W due an upper-level trough. Moderate to fresh trade winds are expected south of 25N through Monday, pulsing to fresh to strong offshore of northern Hispaniola during the afternoon through evening hours each day. southerly winds will increase to fresh to locally strong west of 77W, from tonight through Sunday night, as the pressure gradient tightens between Subtropical Storm Alberto in the Gulf of Mexico and high pressure across the area. Those conditions should improve by Tuesday, as the pressure gradient weakens. For additional information please visit http://www.hurricanes.gov/marine $$ ERA