000 WTNT41 KNHC 280844 TCDAT1 Subtropical Storm Alberto Discussion Number 13 NWS National Hurricane Center Miami FL AL012018 400 AM CDT Mon May 28 2018 Alberto is holding its strength this morning. The Air Force Hurricane Hunters investigated the cyclone a few hours ago and found winds to the north of the center that still support an intensity of about 55 kt. The aircraft data and a NOAA buoy near the center also indicate that the minimum pressure has dropped a little more to 990 mb. Deep convection remains patchy, however, due to pronounced dry slots, but Doppler radar images do show some convective bands moving onshore over the Florida Panhandle. Given the short period of time before Alberto makes landfall, its overall ragged appearance, and proximity to dry air, little change in strength is expected before the subtropical storm reaches the coast this afternoon. Once Alberto is inland, land interaction should cause steady weakening to a subtropical depression tonight or early Tuesday and to a remnant low by Tuesday afternoon. The global models show the low being absorbed by a frontal system over the Great Lakes region by day 5. The NHC intensity forecast is largely an update of the previous one, and is in line with the majority of the guidance. The center of Alberto has wobbled to the left and slowed down significantly during the past 6 hours, but a longer-term motion is northwestward, or 315 degrees, at 6 kt. A north-northwestward to northward motion along the western periphery of a mid-level ridge is expected during the next few days taking Alberto, or its remnants, over the Florida Panhandle and then well inland over the Tennessee and Ohio Valleys. A turn to the northeast is predicted before Alberto's remnants are absorbed by the above-mentioned frontal system. The models are in fairly good agreement, and only small changes were made to the previous NHC track prediction. KEY MESSAGES: 1. Heavy rainfall will lead to a significant risk of flash flooding across the Florida Panhandle, much of Alabama, and western Georgia through tonight, spreading northward into northern Georgia, the western Carolinas, and Tennessee on Tuesday. A risk of flooding and flash flooding will continue over western Cuba, the Florida Keys, and southern Florida today. 2. Hazardous storm surge is possible along portions of the eastern Gulf Coast today, including areas well east of the track of Alberto's center. Residents in the storm surge watch area are encouraged to follow guidance given by their local government officials. 3. Tropical storm conditions are likely within portions of the tropical storm warning area today. 4. Dangerous surf and rip current conditions will continue to affect portions of the eastern and northern Gulf Coast through Tuesday. FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 28.6N 86.2W 55 KT 65 MPH 12H 28/1800Z 30.1N 86.6W 55 KT 65 MPH 24H 29/0600Z 32.1N 86.9W 35 KT 40 MPH...INLAND 36H 29/1800Z 34.6N 87.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 30/0600Z 37.4N 87.6W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 31/0600Z 43.0N 86.3W 15 KT 15 MPH...POST-TROP/REMNT LOW 96H 01/0600Z 48.0N 81.0W 15 KT 15 MPH...POST-TROP/REMNT LOW 120H 02/0600Z...DISSIPATED $$ Forecaster Cangialosi