000 AXNT20 KNHC 270002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 802 PM EDT Sat May 26 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 2300 UTC. ...SPECIAL FEATURES... The center of Subtropical Storm Alberto, at 26/2100 UTC, is near 23.3N 85.1W, or about 275 km SW of the Dry Tortugas, and about 155 km N of the western tip of Cuba. The estimated minimum central pressure is 999 mb. The maximum sustained wind speeds are 35 knots with gusts to 45 knots. It is moving northward, or 10 degrees, 11 knots. Precipitation: widely scattered moderate to isolated strong rainshowers cover the area that extends from 20N to 25N between 75W and 85W, from Cuba and its surrounding waters to the Bahamas, to parts of Florida and all the surrounding waters. isolated to widely scattered moderate rainshowers cover the rest of the areas from 25N to 30N between 75W and 87W, across Florida, the Bahamas and Atlantic Ocean, the Gulf of Mexico, and parts of the Gulf coast of the U.S.A. The 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... An Atlantic Ocean tropical wave is along 21W/23W south of 15N. The wave shows up well in lower level precipitable water imagery. Precipitation: isolated moderate to locally strong rainshowers cover the area that extends from 06N southward between 20W and 30W in the ITCZ. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Guinea near 11N15W to 05N21W. The ITCZ continues from 05N21W to 02N27W, crossing the Equator along 34W, to 01S37W, and 01S46W along the coast of Brazil. Precipitation: isolated moderate to locally strong rainshowers are from 10W eastward, and within 210 nm on either side of the line 07N12W 03N25W, to the Equator along 36W, and along the Equator along 50W. ...DISCUSSION... GULF OF MEXICO... Please read the SPECIAL FEATURES section, for information about Subtropical Storm Alberto, in the SE corner of the Gulf of Mexico. An sharp negatively tilted upper level trough extends from the lower Mississippi Valley to over the Yucatan Channel. Scattered convection remains active over the eastern Gulf, on the side of this trough, with deep layer dry air west of the trough axis. Seas are likely 6 to 9 ft over the southeast Gulf and building ahead of Alberto's approach. Moderate to fresh SE winds are noted over the northeast Gulf, with 3 to 5 ft seas. Light winds with 1 to 3 ft seas are noted over the western Gulf. Fresh southerly flow will persist over the eastern Gulf through mid week in the wake of Alberto. Subtropical Storm Alberto near 23.3N 85.1W 999 mb at 5 PM EDT moving N at 11 kt. Maximum sustained winds 35 kt gusts 45 kt. Alberto will move to 25.4N 84.9W Sun morning...27.5N 85.3W Sun afternoon...28.9N 86.3W Mon morning...30.0N 87.0W Mon afternoon...and inland to 33.6N 87.9W Tue afternoon. Winds and seas will start to decrease thereafter. CARIBBEAN SEA... Please read the SPECIAL FEATURES section, for information about Subtropical Storm Alberto, in the SE corner of the Gulf of Mexico. An upper level trough extends from north central Gulf of Mexico, across the Yucatan Peninsula of Mexico, into the NW corner of the Caribbean Sea. Scattered to numerous strong rainshowers cover the coastal plains and coastal waters from NE Honduras to NE Costa Rica, and in northern sections of Colombia. The winds and the sea heights will continue to decrease in the western Caribbean Sea, given that Alberto is moving out of the area more and more. The winds and the sea heights will continue to decrease in the western Caribbean Sea. High pressure in the central Atlantic Ocean will maintain fresh to strong trade winds in the central Caribbean Sea through early next week, with the strongest winds along the coast of Colombia and in the Gulf of Venezuela. ATLANTIC OCEAN... Please read the SPECIAL FEATURES section, for information about Subtropical Storm Alberto, in the SE corner of the Gulf of Mexico. Moderate to fresh trade winds are expected S of 25N through Monday, pulsing to fresh to strong offshore of northern Hispaniola during the afternoon through evening hours each day. SE to S winds will increase to fresh to locally strong W 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 $$ MT