ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM Tropical Storm Laura Discussion Number 13 NWS National Hurricane Center Miami FL AL132020 1100 PM AST Sat Aug 22 2020 Laura is now located near the eastern portion of the Dominican Republic, and it is producing a large area of showers and thunderstorms over much of Hispaniola and adjacent areas. The NOAA Hurricane Hunters have been flying in the tropical storm this evening and have found winds to support maintaining the initial intensity of 45 kt. Dropsonde data from the aircraft suggests that the pressure has fallen a little to 1003 mb, and that the center is still quite elongated. Laura is moving west-northwestward at 14 kt. The track forecast reasoning is generally unchanged from earlier. A subtropical high pressure system is expected to build westward during the next few days, which should continue to steer Laura generally west-northwestward at a fairly quick pace. This track should take the storm across Hispaniola tonight and early Sunday and then across Cuba late Sunday and Monday. Laura is then expected to emerge over the eastern Gulf of Mexico, where it will likely turn northwestward and slow down some as it reaches the western side of the ridge. The models are in fair agreement that Laura will generally follow a similar path to Marco when it nears the northern Gulf coast in 3 to 4 days. There has been little change in the guidance this cycle, and the NHC track forecast is largely an update of the previous one. This forecast is near the typically reliable TVCA and HCCA consensus aids. Since the tropical storm is expected to track across the mountainous islands of Hispaniola and Cuba during the next 36 to 48 hours, little change in intensity seems like a good bet during that time period. However, after the storm pulls away from the islands and moves over the warm Gulf of Mexico waters while being in low wind shear and high moisture conditions, strengthening seems very likely. Most of the better-performing intensity models show Laura making landfall along the U.S. northern Gulf coast as a hurricane in about 4 days. The NHC intensity forecast is slightly higher than the previous one, and it lies roughly near the middle of the guidance suite. Key Messages: 1. Tropical storm conditions are expected to continue across portions of the U.S. Virgin Islands and Puerto Rico for a few more hours. Tropical storm conditions are also expected across portions of the Dominican Republic and Haiti, the Turks and Caicos, the southeastern Bahamas, and central and eastern Cuba through Sunday. Heavy rainfall is likely across these areas and could cause mudslides and flash and urban flooding through Sunday, with widespread river flooding possible in Puerto Rico. 2. Tropical storm conditions are possible over portions of central and western Cuba, the central Bahamas and Andros Island Sunday night and Monday, and in the Florida Keys on Monday. 3. The details of the long-range track and intensity forecasts remain uncertain since Laura is forecast to move near or over portions of the Greater Antilles through Monday. However, Laura is forecast to strengthen over the Gulf of Mexico and could bring storm surge, rainfall, and wind impacts to portions of the U.S. Gulf Coast by the middle of next week. This could result in a prolonged period of hazardous weather for areas that are likely to be affected by Tropical Storm Marco earlier in the week. Interests there should monitor the progress of Laura and Marco and updates to the forecast during the next few days. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 18.3N 69.6W 45 KT 50 MPH 12H 23/1200Z 19.3N 72.3W 45 KT 50 MPH...INLAND 24H 24/0000Z 20.6N 76.0W 45 KT 50 MPH...INLAND 36H 24/1200Z 22.1N 79.6W 45 KT 50 MPH...INLAND 48H 25/0000Z 23.4N 83.0W 50 KT 60 MPH...OVER WATER 60H 25/1200Z 24.7N 85.8W 60 KT 70 MPH 72H 26/0000Z 26.2N 88.0W 75 KT 85 MPH 96H 27/0000Z 29.8N 91.2W 80 KT 90 MPH...INLAND 120H 28/0000Z 34.7N 89.6W 30 KT 35 MPH...INLAND $$ Forecaster Cangialosi NNNN