Hawaii braces for Hurricanes Iselle and Julio

Tropical Storm Julio strengthened into a hurricane early Wednesday, chasing Hurricane Iselle toward the Hawaiian islands.

Read MoreHawaii faces 'unprecedented' double-whammy of storms

The islands' emergency management agency said the rare threat of two major storms in such close proximity was "a call to prepare." Julio packed maximum sustained winds of 75 miles per hour as it became the fifth hurricane of the season.

Hurricane Iselle
Source: NOAA | Facebook
Hurricane Iselle

It trailed shortly behind Iselle—a strong Category 2 hurricane—less than 900 miles from the island of Hilo early Wednesday. Iselle carried maximum sustained winds of around 100 miles per hour, along with bigger gusts.

While Iselle is expected to weaken this week, The Weather Channel reported that it could could still reach the Hawaiian Islands as a strong tropical storm or even a hurricane late Thursday.

Read More Second 2014 hurricane appears

Hawaiians raced to stock up on supplies, with stores re-stocking shelves of bottled water, baby supplies and canned meat as soon as they emptied, according to The Associated Press.

By Cassandra Vinograd, NBC News