A solar-powered plane that is attempting to cross the Pacific Ocean is encountering its first weather front.

It will have to navigate a route through the wall of clouds and rain to continue its epic journey to Hawaii.

Solar Impulse took off from Japan's Nagoya Airfield at 18:03 GMT on Sunday, and is expected to spend about 120 hours in the air.

It will have to cross another front on the fourth or fifth day of the flight.

The plane has now entered US airspace, and has set the record for the longest flight made by a solar plane.

If the pilot, Solar Impulse co-founder Andre Borschberg, completes the journey, he will also have achieved the longest-duration solo flight in aviation history.