Hurricane Iselle hit Hawaii’s Big Island late Thursday with high winds and heavy rain, as the rest of the Aloha State braced for a second hurricane, Julio, tracking closely behind. Hurricanes have hit the US’ Pacific island group only three times since 1950.

On Friday, tropical storm Iselle downed trees, caused flooding and knocked out power to 21,000 homes, mainly on Big Island. Airlines canceled about 50 flights. Stores and schools were closed. No major injuries were reported.

Visitors to the island were evacuated to 12 Red Cross shelters on higher ground. In Hilo, on the east side of the island, most of the 43,000 residents were bracing the storm out at home after stocking up on water, food and other essentials in recent days.

After Iselle moves out, state officials say they believe there will be a break in the weather for a Democratic primary election to be held on Saturday as scheduled.

Hurricane Julio is forecast to reach Hawaii Sunday, on a path that would take it just north of the island chain but close enough to cause more potential damage.

Gov. Neil Abercrombie, whose political fate will be decided Saturday, signed an emergency proclamation in anticipation of the two storms which allows easier access to emergency resources at the state and federal levels.

The primary vote Saturday pits Gov. Neil Abercrombie against state Sen. David Ige. Meanwhile U.S. Sen. Brian Schatz seeks the party’s nomination to retain his seat. He is being challenged by U.S. Rep. Colleen Hanabusa.

All but two polling stations on the east coast of the Big Island hardest hit by Tropical Storm Iselle will be open, election officials said.

Hurricane Julio, which was downgraded to a Category 2 storm on Friday, was packing maximum winds of 100 mph (155 kph) as it churned about 590 miles (955 km) off the Big Island city of Hilo and 780 miles (1,255 km) east of the state capital Honolulu, the National Weather Service said late on Friday night.