000 WTNT45 KNHC 041457 TCDAT5 Tropical Storm Elsa Discussion Number 17 NWS National Hurricane Center Miami FL AL052021 1100 AM EDT Sun Jul 04 2021 A NOAA P-3 Hurricane Hunter aircraft has been investigating Elsa this morning. Flight-level and SFMR surface observations from the aircraft indicate that the maximum winds are near 50 kt and the estimated central pressure, about 1009 mb, is rather high for a system of this intensity. Also, tail Doppler radar data from the aircraft show an eastward tilt of the center with height. Nonetheless, the storm still looks fairly impressive on satellite images with a well-defined convective banding feature over the northern through eastern portions of the circulation. Also, the highest cloud tops are quite cold and near -70C. Elsa's forward speed has slowed a little more, and the current motion is around 290/11 kt. There hasn't been much change to the track forecast or reasoning since the previous advisory. Over the next few days, the tropical cyclone should move around the western periphery of the subtropical ridge. The NHC forecast track is similar to the previous official forecast, and close to the model consensus. The latest GFS and HWRF solutions are to the west of this forecast. Elsa should remain in a low-shear environment through Monday, and some strengthening is likely before the storm reaches Cuba, assuming the circulation becomes better aligned vertically. The storm should weaken somewhat due to its passage over Cuba. After the cyclone emerges into the southeastern Gulf of Mexico, only slight restrengthening is forecast due to moderate southwesterly shear. The official intensity forecast is on the high end of the numerical intensity guidance suite. Key Messages: 1. Widespread heavy rain will continue to affect portions of southern Haiti and Jamaica today where isolated to scattered flash flooding and mudslides will be possible. Heavy rain will then impact the Cayman Islands and Cuba today into Monday resulting in significant flooding and mudslides over Cuba. As Elsa approaches the Florida Keys and Florida Peninsula Monday through Wednesday, heavy rainfall may result in isolated flash, urban, and minor river flooding. 2. Tropical storm conditions and dangerous storm surge are expected with hurricane conditions possible in portions of eastern Cuba later today and tonight. Tropical storm conditions are expected in portions of central and western Cuba tonight and Monday. 3. Tropical storm conditions, storm surge, and rainfall impacts are expected beginning late Monday in the Florida Keys, and are possible along the coast of southwestern Florida beginning Monday night. Tropical Storm Warnings and Watches are in effect in those areas. 4. There is a risk of tropical storm conditions, storm surge, and rainfall impacts along the remainder of the Florida Peninsula Monday night through Wednesday and the coasts of Georgia and the Carolinas Wednesday and Thursday. However, uncertainty in the forecast remains larger than usual due to Elsa's potential interaction with Cuba. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 18.7N 76.8W 50 KT 60 MPH 12H 05/0000Z 20.2N 78.2W 55 KT 65 MPH 24H 05/1200Z 21.9N 80.0W 60 KT 70 MPH...INLAND 36H 06/0000Z 23.4N 81.5W 50 KT 60 MPH...OVER WATER 48H 06/1200Z 24.7N 82.5W 50 KT 60 MPH 60H 07/0000Z 26.5N 83.0W 50 KT 60 MPH 72H 07/1200Z 28.6N 82.8W 50 KT 60 MPH 96H 08/1200Z 33.5N 79.5W 40 KT 45 MPH...INLAND 120H 09/1200Z 38.5N 71.0W 35 KT 40 MPH...OVER WATER $$ Forecaster Pasch