000 AXNT20 KNHC 270525 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 125 AM 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... The center of Subtropical Storm Alberto, at 27/0300 UTC, is near 23.9N 84.6W, or about 195 km WSW of the Dry Tortugas, and about 645 km S of Apalachicola Florida. The estimated minimum central pressure is 1001 mb. The maximum sustained wind speeds are 35 knots with gusts to 45 knots. It is moving NNE, or 15 degrees, 11 knots. Precipitation: widely scattered moderate to isolated strong rainshowers cover the area that extends from 21N to 26N between 76W 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 73W and 88W, 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 23W/24W south of 13N. 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 09N13W to 05N22W. The ITCZ continues from 04N25W to the Equator along 38W, to 01S37W, and 01S46W along the coast of Brazil. Precipitation: isolated moderate to locally strong rainshowers are from 10W eastward, and to the south of the line 08N16W 05N30W 04N51W. scattered to numerous strong rainshowers have reached the coastal waters of Sierra Leone and Liberia, possibly with the next tropical wave that still is inland. ...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. A NW-to-SE oriented upper level trough passes through Louisiana, beyond the Yucatan Channel, into the NW corner of the Caribbean Sea. Subtropical Storm Alberto near 23.9N 84.6W 1001 mb at 11 PM EDT moving NNE at 11 kt. Maximum sustained winds 35 kt gusts 45 kt. Alberto will move to 25.9N 84.6W Sunday morning, 27.7N 85.6W Sunday evening, 28.9N 86.4W Monday morning, 30.4N 86.8W Monday evening, and inland to 34.5N 87.6W Tuesday evening. The winds and the sea heights will start to decrease following landfall. 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. Subtropical Storm Alberto in the SE Gulf of Mexico near 23.9N 84.6W 1001 mb at 11 PM EDT moving NNE at 11 kt. Maximum sustained winds 35 kt gusts 45 kt. 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. High pressure in the central Atlantic Ocean will maintain fresh to strong trade winds in the central Caribbean Sea 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, for information about Subtropical Storm Alberto, in the SE corner of the Gulf of Mexico. The surface pressure gradient between Subtropical Storm Alberto and the Atlantic Ocean surface ridge may support increasing wind speeds to near gale force in the Florida coastal and offshore waters this afternoon and tonight. Upper level cyclonic wind flow covers the area that extends from 18N northward between 50W and 70W, with an upper level trough. Precipitation: isolated to widely scattered moderate rainshowers are from 18N northward between 50W and 66W. A surface ridge extends from a 1028 mb high pressure center that is near 33N38W, to 29N47W, 29N63W, beyond 31N81W at the coast of Georgia. 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. It is possible that a cold front or a frontal trough may drop into the NE waters from Wednesday through Thursday. For additional information please visit http://www.hurricanes.gov/marine $$ MT