Update — July 3, 4:42 p.m. ET: Astronaut Gerst posted this image of the newly formed hurricane.
Update — 7:11 p.m. ET: Astronaut Reid Wiseman posted an image of storms over Maryland.
Update — 5:04 p.m. ET
Tropical Storm Arthur is almost a hurricane. The hurricane warning has been issued for the North Carolina coast with strong winds and flooding likely for both Carolinas until Friday.