| Track: https://www.nhc.noaa.gov/refresh/graphics_at1+shtml/?cone#contents This part of the discussion was interesting. "The highest flight-level wind (102 kt) was actually measured within the outer band that is moving onshore in the Wilmington area. However, the highest SFMR-measured wind was 73 kt, and the highest land observation so far was a sustained wind of 72 kt at Cape Lookout, North Carolina. On top of that, NOAA Doppler radar velocities have been running around 100 kt at about 5,000 feet. All of these data support reducing the initial intensity to 80 kt, but based on the higher flight-level winds, the gust factor is being set a little higher than is typical for an 80-kt hurricane." Hurricane Florence Advisory Number 59 NWS National Hurricane Center Miami FL AL062018 1100 PM EDT Thu Sep 13 2018 ...LIFE-THREATENING STORM SURGE AND HURRICANE-FORCE WINDS OCCURRING ALONG THE NORTH CAROLINA COAST... ...THREAT OF FRESHWATER FLOODING WILL INCREASE OVER THE NEXT SEVERAL DAYS... SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...34.0N 76.8W ABOUT 50 MI...80 KM S OF MOREHEAD CITY NORTH CAROLINA ABOUT 60 MI...95 KM ESE OF WILMINGTON NORTH CAROLINA MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/H PRESENT MOVEMENT...NW OR 305 DEGREES AT 6 MPH...9 KM/H MINIMUM CENTRAL PRESSURE...956 MB...28.23 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Storm Surge Watch has been discontinued north of Duck North Carolina. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... South Santee River South Carolina to Duck North Carolina Albemarle and Pamlico Sounds, including the Neuse and Pamlico Rivers A Storm Surge Watch is in effect for... Edisto Beach South Carolina to South Santee River South Carolina A Hurricane Warning is in effect for... South Santee River South Carolina to Duck North Carolina Albemarle and Pamlico Sounds A Hurricane Watch is in effect for... Edisto Beach South Carolina to South Santee River South Carolina A Tropical Storm Warning is in effect for... North of Duck North Carolina to Cape Charles Light Virginia Chesapeake Bay south of New Point Comfort Edisto Beach South Carolina to South Santee River South Carolina Interests elsewhere in the southeastern and mid-Atlantic states should monitor the progress of Florence. A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area, in this case within the next 24 hours. A Hurricane Watch means that hurricane conditions are possible within the watch area. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM EDT (0300 UTC), the center of the eye of Hurricane Florence was located by NOAA Doppler radar and an Air Force Reserve Hurricane Hunter aircraft near latitude 34.0 North, longitude 76.8 West. Florence is moving toward the northwest near 6 mph (9 km/h). A turn toward the west-northwest and west at a slow forward speed is expected through Friday, followed by a slow west-southwestward motion Friday night and Saturday. On the forecast track, the center of Florence is expected to move inland across extreme southeastern North Carolina and extreme eastern South Carolina Friday and Saturday. Florence will then recurve across the western Carolinas and the central Appalachian Mountains early next week. Data from the Hurricane Hunter aircraft, coastal surface observations, and NOAA Doppler radar indicate that maximum sustained winds are near 90 mph (150 km/h) with higher gusts. Little change in strength is expected before Florence moves inland on Friday. More significant weakening is expected over the weekend and into early next week while Florence moves farther inland. Hurricane-force winds extend outward up to 80 miles (130 km) from the center, and tropical-storm-force winds extend outward up to 195 miles (315 km). A Weatherflow station at Fort Macon, North Carolina recently reported a sustained wind of 77 mph (124 km/h) with a gust to 100 mph (161 km/h). A storm surge of 10 feet above normal levels was reported by the National Weather Service office in Morehead City, North Carolina, at the Cherry Branch Ferry Terminal on the Neuse River, courtesy of the North Carolina Department of Transportation. The minimum central pressure reported by the aircraft is 956 mb (28.23 inches). HAZARDS AFFECTING LAND ---------------------- STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water has the potential to reach the following heights above ground... Cape Fear NC to Cape Lookout NC...7-11 ft, with locally higher amounts in the Neuse, Pamlico, Pungo, and Bay Rivers Cape Lookout NC to Ocracoke Inlet NC...6-9 ft South Santee River SC to Cape Fear NC...4-6 ft Ocracoke Inlet NC to Salvo NC...4-6 ft Salvo NC to Duck NC...2-4 ft Edisto Beach SC to South Santee River SC...2-4 ft The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and destructive waves. Surge-related flooding can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office. RAINFALL: Florence is expected to produce heavy and excessive rainfall in the following areas... Southeastern coastal North Carolina into far northeastern South Carolina...20 to 30 inches, isolated 40 inches. This rainfall will produce catastrophic flash flooding and prolonged significant river flooding. Remainder of South Carolina and North Carolina into southwest Virginia...6 to 12 inches, isolated 15 inches. This rainfall will produce life-threatening flash flooding. WIND: Hurricane conditions are occuring over portions of the coast of North Carolina and are expected to spread across portions of southeastern North Carolina and eastern South Carolina through Friday. Tropical storm conditions are expected to spread inland across the remainder of the warning area through Saturday. TORNADOES: A few tornadoes are possible in eastern and southeastern North Carolina through Friday. SURF: Swells generated by Florence are affecting Bermuda, portions of the U.S. East Coast, and the northwestern and central Bahamas. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 200 AM EDT. Next complete advisory at 500 AM EDT. $$ Forecaster Berg Hurricane Florence Discussion Number 59 NWS National Hurricane Center Miami FL AL062018 1100 PM EDT Thu Sep 13 2018 Radar imagery and data from an Air Force Reserve Hurricane Hunter flight indicate that Florence has an inner eye that is open on the east side, and a secondary wind maximum that has already begun to spread inland across southeastern North Carolina. The highest flight-level wind (102 kt) was actually measured within the outer band that is moving onshore in the Wilmington area. However, the highest SFMR-measured wind was 73 kt, and the highest land observation so far was a sustained wind of 72 kt at Cape Lookout, North Carolina. On top of that, NOAA Doppler radar velocities have been running around 100 kt at about 5,000 feet. All of these data support reducing the initial intensity to 80 kt, but based on the higher flight-level winds, the gust factor is being set a little higher than is typical for an 80-kt hurricane. Florence has been wobbling a little since the previous advisory, but the 12-hour motion is northwestward, or 305/5 kt. Nearly all of the track models agree that Florence will turn westward or west-southwestward during the next 36 hours, bringing the hurricane's center inland over extreme southern North Carolina and extreme eastern South Carolina Friday and Friday night. After 48 hours, Florence is expected to recurve across the western Carolinas and the central Appalachian Mountains around a western Atlantic ridge. No major changes were required to the NHC official track forecast, and it is generally close to the multi-model consensus aids. It should be noted that the ECMWF, HCCA, and Florida State Superensemble still take Florence on a more southern track, straddling the coast of South Carolina before turning inland. While that is not shown by the official forecast, it cannot yet be ruled out as a possibility. Florence's intensity is not likely to change much in the 12 hours or so it has left over water. Once the center moves inland, the intensity is forecast to decrease. However, since a good portion of Florence's circulation will remain over water for the next 36-48 hours, the NHC intensity forecast is a blend of the regular SHIPS model (which assumes a storm staying over water) and the Decay-SHIPS model (which assumes the storm has moved inland). Based on that, Florence should weaken to a tropical storm just after 24 hours and then below tropical storm strength after 48 hours. Florence remains a large hurricane. Life-threatening storm surge, heavy rainfall, and damaging wind will cover a large area regardless of exactly where the center of Florence moves. Key Messages: 1. A life-threatening storm surge is already occurring along portions of the North Carolina coast and will continue through Friday. 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 as it approaches the coast and 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 on Friday. 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 14/0300Z 34.0N 76.8W 80 KT 90 MPH 12H 14/1200Z 34.2N 77.6W 75 KT 85 MPH 24H 15/0000Z 34.0N 78.5W 65 KT 75 MPH...INLAND 36H 15/1200Z 33.8N 79.2W 50 KT 60 MPH...INLAND 48H 16/0000Z 33.8N 80.2W 40 KT 45 MPH...INLAND 72H 17/0000Z 35.5N 82.9W 25 KT 30 MPH...INLAND 96H 18/0000Z 39.5N 82.0W 20 KT 25 MPH...POST-TROP/INLAND 120H 19/0000Z 44.0N 72.5W 25 KT 30 MPH...POST-TROP/INLAND $$ Forecaster Berg |