Hurricane Erin moved southeast of Cape Hatteras on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Hurricane Erin was located at latitude 32.8°N and longitude 73.1°W which put the center about 215 miles (345 km) southeast of Cape Hatteras, North Carolina. Erin was moving toward the north-northeast at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h). The minimum surface pressure was 942 mb.
A Tropical Storm Warning is in effect for the portion of the coast from Beaufort Inlet, North Carolina to Chincoteague, Virginia.
A Storm Surge Warning is in effect for the portion of the coast from Cape Lookout to Duck, North Carolina.
A Tropical Storm Watch is in effect for Bermuda.
Concentric eyewalls formed again in Hurricane Erin on Wednesday. The inner eyewall had a radius of 17 miles (28 km). The outer eyewall had a radius of 75 miles (120 km). The strongest winds were occurring in the outer eyewall. Bands of showers and thunderstorms were revolving around the concentric eyewalls. Storms near the center of Erin generated strong upper level divergence that pumped mass away from the hurricane. The removal of large quantities of mass caused the surface pressure to decrease on Wednesday.
The circulation around Hurricane Erin was very large. Winds to hurricane force extend out 90 miles (145 km) from the center of Erin’s circulation. Winds to tropical storm force extend out 265 miles (425 km) from the center of Hurricane Erin.
The Hurricane Intensity Index (HII) for Hurricane Erin is 19.2. The Hurricane Size Index (HSI) is 33.0 and the Hurricane Wind Intensity Size Index (HWISI) is 52.2. Hurricane Erin is similar in size and intensity to Hurricane Ike when Ike hit Texas in 2008.
Hurricane Erin will move through an environment that will become unfavorable for intensification during the next 24 hours. Erin will move over water where the Sea Surface Temperatures are near 28°C. It will move under the eastern side of an upper level trough over the Northeast U.S. and the Great Lakes. The upper level trough will produce southeasterly winds that will blow toward the top of Erin’s circulation. Those winds will cause the vertical wind shear to increase on Thursday. Hurricane Erin will start to weaken when the vertical wind shear increases.
The upper level trough over the Northeast U.S. and the Great Lakes will steer Hurricane Erin toward the northeast during the next 24 hours. On its anticipated track, the center of Hurricane Erin will be move away from Cape Hatteras on Thursday. Erin will pass far to the south of Long Island on Thursday.
The large circulation around Hurricane Erin will produce large waves that will move toward the east coast of the U.S. Erin could cause a storm surge of up to four feet (one meter) along the Outer Banks of North Carolina. Mandatory evacuations have been ordered for Hatteras Island and Ocracoke Island. Water is already washing over parts of Hatteras Island. The large waves are likely to cause significant beach erosion. The large circulation around Hurricane Erin could also bring tropical storm force winds to the Outer Banks. Conditions along the Outer Banks should start to improve on Friday when Hurricane Erin moves farther away.
