The potential risks posed by Hurricane Erin prompted the issuance of a Tropical Storm Watch and a Storm Surge Watch for the North Carolina Outer Banks on Monday afternoon.  At 5:00 p.m. EDT on Monday the center of Hurricane Erin was located at latitude 24.0°N and longitude 71.3°W which put the center about 815 miles (1310 km) south-southeast of Cape Hatteras, North Carolina.  Erin was moving toward the northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (265 km/h).  The minimum surface pressure was 937 mb.

A Tropical Storm Watch is in effect for the portion of the coast from Beaufort Inlet to Duck, North Carolina.  The Tropical Storm Watch includes Pamlico Sound.

A Storm Surge Watch is in effect for the portion of the coast from Cape Lookout to Duck, North Carolina.

A Tropical Storm Warning is in effect for the Turks and Caicos.  A Tropical Storm Warning is in effect for the Southeast Bahamas.

A Tropical Storm Watch is in effect for the Central Bahamas.

Hurricane Erin was maintaining its intensity on Monday afternoon.  A circular eye with a diameter of 45 miles (75 km) was at the center of Erin’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Erin’s circulation.  Storms near the core of Erin were generating strong upper level divergence that was pumping mass away from the hurricane.  The removal of mass in the upper levels was approximately equal to the inflow of mass in the lower levels of the atmosphere/  The balance of outflow and inflow of mass caused the surface pressure to remain nearly constant.

An earlier eyewall replacement cycle increased the size of the circulation around Hurricane Erin.  Winds to hurricane force extended out 80 miles (130 km) from the center of Erin’s circulation.  Winds to tropical storm force extended out 230 miles (370 km) from the center of Hurricane Erin.

The Hurricane Intensity Index (HII) for Hurricane Erin is 28.3.  The Hurricane Size Index (HSI) is 24.4 and the Hurricane Wind Intensity Size Index (HWISI) is 52.7.  Hurricane Erin is similar in size and intensity to Hurricane Helene in 2024.

Hurricane Erin will move through an environment that will become less favorable for intensification during the next 24 hours.  Erin will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  However, Erin will move into a region of drier air on Tuesday.  The drier air is likely to cause Hurricane Erin to start to weaken slowly.

Hurricane Erin will move around the southwestern side of a high pressure system over the Atlantic Ocean.  The high pressure system will steer Erin toward the northwest during the next 24 hours.  On its anticipated track, the center of Hurricane Storm Erin will pass of the Bahamas on Tuesday.

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.  The large waves could also cause significant beach erosion.  The large circulation around Hurricane Erin could also bring tropical storm force winds to the Outer Banks.

Bands in the western side of Hurricane Erin will continue to bring gusty winds and heavy rain to the Turks and Caicos and to the Southeast Bahamas until Erin moves farther away. The gusty winds and heavy rain could spread over the Central Bahamas on Tuesday.  Heavy rain could cause floods in some locations.