000 AXNT20 KNHC 261205 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM 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 0600 UTC surface analysis and satellite imagery through 1130 UTC. ...SPECIAL FEATURES... Subtropical Storm Alberto centered near 19.9N 85.6W at 26/0900 UTC moving NNE at 6 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Alberto is interacting with an upper trough, and remains deeply sheared. Thunderstorm activity has diminished slightly recently, and is displaced well to the east of the low level center. However, widespread showers and thunderstorms persist over Cuba, South Florida, and the eastern Gulf of Mexico on the east side of the upper trough. The forecast calls for gradual development as Alberto moves northward into the south central Gulf of Mexico, as either a tropical or subtropical storm. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 19W/20W from 13N southward. The wave shows up well in lower level precipitable water imagery. Scattered moderate to widely scattered strong rainshowers are from 03N to 07N between 13W and 25W. An Atlantic Ocean tropical wave is along 55W/56W, moving across Suriname. Isolated moderate rainshowers are from 10N southward between 50W and 60W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Guinea- Bissau near 12N16W, to 03N25W. The ITCZ continues from 03N25W to 00N40W. Scattered convection is observed from 04S to 02N between 30W and 50W. ...DISCUSSION GULF OF MEXICO... Please read the SPECIAL FEATURES section, for information about Subtropical Storm Alberto, in the NW corner of the Caribbean Sea. An upper level trough extends from the north central Gulf of Mexico, across the Yucatan Peninsula of Mexico, into the NW corner of the Caribbean Sea. Alberto will intensify while moving northward, reaching 21.6N 85.1W this afternoon with wind speeds of 35 kt gusting to 45 kt. Alberto will transition to a tropical cyclone Sun afternoon centered near 26.2N 85.9W with wind speeds of 50 kt gusting to 60 kt, near 27.5N 86.8W Mon night with wind speeds of 55 kt gusting to 65 kt, then near the coast off the western Florida Panhandle and the coast of Alabama late Tuesday. CARIBBEAN SEA... 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 are from 16N to 18N between 16W and 18W. Please read the SPECIAL FEATURES section, for information about Subtropical Storm Alberto, in the NW corner of the Caribbean Sea. Alberto move through the Yucatan Channel into the south central Gulf today, with winds and seas decreasing in the western Caribbean Sea thereafter. High pressure in the central Atlantic will maintain fresh to strong trade winds in the central Caribbean Sea through early next week, with 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 NW corner of the Caribbean Sea. 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 Saturday night through Sunday night. The pressure gradient will tighten between Subtropical Storm Alberto in the Gulf of Mexico and high pressure elsewhere. Those conditions should improve by Tue as the pres gradient slackens. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen