755 WTNT41 KNHC 140842 TCDAT1 Hurricane Florence Discussion Number 60 NWS National Hurricane Center Miami FL AL062018 500 AM EDT Fri Sep 14 2018 An Air Force Hurricane Hunter aircraft has been investigating Florence over the past few hours. Data from the aircraft indicate little change in the intensity with the central pressure holding fairly steady. The current intensity estimate is kept at 80 kt for this advisory. There were a couple of SFMR-observed surface winds that were a little higher than that value, however these observations were very near Cape Lookout North Carolina, where shoaling likely caused some inflated wind speeds. The current intensity estimate is also consistent with peak WSR-88D Doppler radar velocities. The center of Florence will be moving inland very soon, but is expected to slow down even more today and tonight. As a result, it will remain fairly close to the coast today, with much of the circulation still over water. Therefore only a gradual decrease in intensity is called for through tonight. Over the weekend, a faster rate of weakening is likely while the center moves at a faster pace and goes farther inland. The hurricane is turning westward as it continues a slow forward motion of about 285/5 kt. Florence is currently in a region of weak steering currents associated with a col between two mid-level anticyclones. Over the next few days, a high pressure area is forecast to build to the east-northeast of the tropical cyclone. As a result, the system should gradually turn northwestward and northward in 2-3 days. Later in the forecast period, Florence should turn northeastward as it approaches the mid-latitude westerlies. The official track forecast is similar to the previous one and about in the middle of the dynamical guidance suite. It cannot be emphasized enough that the most serious hazard associated with slow-moving Florence is extremely heavy rainfall, which will cause disastrous flooding that will be spreading inland through the weekend. Key Messages: 1. A life-threatening storm surge is already occurring along portions of the North Carolina coast and will continue through today and tonight. This surge is also likely along portions of the South Carolina coast. The greatest storm surge inundation is expected between Cape Fear and Cape Hatteras, including the Neuse and Pamlico Rivers and western Pamlico Sound. 2. Life-threatening, catastrophic flash flooding and prolonged significant river flooding are likely over portions of the Carolinas and the southern and central Appalachians through early next week, as Florence is expected to slow down while it moves inland. 3. Damaging hurricane-force winds are occurring along portions of the North Carolina coast and are expected to spread to portions of the South Carolina coast later today. Strong winds could also spread inland into portions of the Carolinas over the next couple of days. 4. Large swells affecting Bermuda, portions of the U.S. East Coast, and the northwestern and central Bahamas will continue this week, resulting in life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 34.2N 77.4W 80 KT 90 MPH 12H 14/1800Z 34.1N 78.3W 75 KT 85 MPH...INLAND 24H 15/0600Z 33.9N 79.1W 65 KT 75 MPH...INLAND 36H 15/1800Z 33.8N 79.9W 45 KT 50 MPH...INLAND 48H 16/0600Z 34.1N 81.1W 35 KT 40 MPH...INLAND 72H 17/0600Z 36.6N 83.2W 25 KT 30 MPH...INLAND 96H 18/0600Z 40.5N 80.5W 25 KT 30 MPH...POST-TROP/INLAND 120H 19/0600Z 43.5N 72.0W 25 KT 30 MPH...POST-TROP/INLAND $$ Forecaster Pasch