Major Hurricane Earl Advisory 33 North Carolina Threat Assessment Prepared at: 11 AM Thursday September 2, 2010 Hurricane and Tropical Storm Warnings in effect for the North Carolina Coast and Sounds NWS Raleigh, NC 1
1100 AM Earl Information Position: 30.9 N 74.8 W, 300 nm south-southeast southeast of Cape Hatteras, NC. Intensity: Winds near 140 mph (cat. 4).. Earl has weakened slightly but will remain a Major Hurricane as it approaches NC tonight. Movement: Initially north northwest (355 degrees) at 18 mph.. Storm has turned a little more to the north as forecast and appears to no longer be moving west. Watches/Warnings: Hurricane Warning from Bogue Inlet to VA border Tropical Storm Warning from Cape Fear to Bogue Inlet 2 AM Fri Impacts: Track: Hurricane Earl forecast unchanged bringing the storm within 60 miles of Cape Hatteras, NC tonight into early Friday morning with winds of 125 mph Wind & Seas: Storm surge forecasts increased to 4 to 6 feet with some higher values possible along the Outer Banks, southern Pamlico Sound and lower Neuse River. A breach of the Outer Banks near Hatteras is possible. Seas up to 25 feet along the Outer Banks will result in significant loss of dune structures and 2 ocean overwash.
Wind Speed Probabilities Tropical Storm Force Winds are expected along the Outer Banks starting Tonight evening (90-100%). Tropical Storm Force Wind 60-70% chance along Highway 17 20-30% chance inland to I-95 and the Triangle depending on storm track. Damaging 58 mph wind expected along the Outer Banks and Pamlico Sound (70-80%) by 12 am Friday. 58 mph Wind 30% chance of damaging winds reaching Highway 17. Hurricane Force Wind Hurricane Force winds are most likely along the coast of NC (50-60%) across the Outer Banks by 12 am Friday. This will depend highly on the exact storm track and intensity which will change over time. 3
Forecast Winds (unchanged) Forecast wind gusts (kt) Tonight into Early Fri Forecast wind speeds based on the current track 65 75 mph gusts along the Outer Banks and Sounds starting around 12 AM Fri. 40 55 mph wind gusts along Highway 17 (higher on the water near New Bern and Washington) 30 35 mph gusts inland to near Interstate 95. Wind forecasts could change with later forecasts.
Coastal Impacts (updated) (from Newport/Morehead City NWS) Seas up to 25 feet (see image) are forecast in the coastal waters. Breakers on the beach of 15 ft will over wash onto the Outer Banks ocean side tonight before midnight, peaking between midnight and 6 AM Friday. High tide will be around 230 AM. A breach/cut of the Outer Banks with loss of highway structure is likely near Cape Hatteras/Buxton as well as other areas of weak dune structure. Forecast Wave Height 12 AM Fri
Storm Surge (increased up to 6 feet) Forecast Storm Surge (3-6 ft) Probability of surge 6 feet or higher 3-6 feet of storm surge expected along the Outer Banks, lower Pamlico Sound and lower Neuse River (above image) Locations/probabilities of storm surge 6 feet or greater (above image) along the Outer Banks, Ocracoke and southern Pamlico Sound (above image)
Forecast Rainfall (unchanged) Rainfall Thursday afternoon into Friday Heaviest rainfall along the Outer Banks (3 5 inches with up to 6 inches possible) Rapid decrease in rainfall amounts west of Highway 17 where an inch or less of rain is forecast. Any flooding from heavy rain should be limited to coastal and sound counties. Rainfall forecasts could change with later forecasts.
Threat Summary Major Hurricane Earl continues to move towards NC passing within 60 miles of Cape Hatteras shortly after 12 AM Friday. Hurricane force winds expected along the Outer Banks with tropical storm force winds as far west as Highway 17. Storm surge of 3 6 feet in combination with waves of 15 feet will create destroy dune structures, over wash of Highway 12 and result in several possible breaches of the the Outer Banks. Sound side surge of 3 6 feet will cause flooding from Hatteras to Ocracoke and Cedar Island. Heaviest rainfall, up to 3 to 5 inches, should primarily remain over the Outer Banks and Sound counties. The official forecast track of Hurricane Earl along with most models turn the storm north late this afternoon barely missing NC. This turn will be critical and a slower northward of the major hurricane would have huge impacts on NC. Everyone with interests over the eastern half of NC should be rushing to prepare for Hurricane Earl completing all activities by this evening prior to sunset. 8