HONOLULU, Shawwal 12, 1435, Aug 8, 2014, SPA -- The center of Tropical Storm Iselle made landfall on Hawaii's Big Island on Friday, bringing strong winds and heavy rain, knocking down trees and causing power outages ahead of a more powerful storm gathering strength behind it, Reuters reported. While Iselle weakened into a tropical storm before reaching the islands, it was being closely followed by Julio, a Category 3 hurricane set to reach the area as early as Sunday morning - although the latest forecasts showed it tracking just north of the archipelago. As Iselle bore down, more than 1,200 people flocked to evacuation shelters across the Big Island, according to County of Hawaii Civil Defense, as heavy rains and strong winds pummeled eastern areas of the island from Puna to Hilo. Hawaii Electric Light Company had about 5,000 customers without power, a Hawaii County official said. Flash flood warnings were issued for the entire island. Iselle was expected to bring waves of up to 25 feet (8 meters) on southeast-facing shores on the Big Island, along with heavy rain and sustained winds near 70 miles per hour (110 kph), before passing south of the state's smaller islands later in the day. About 870 miles to the east, Hurricane Julio had gained momentum, barreling west-northwest at 16 miles per hour (26 kph), with maximum sustained winds of 105 miles per hour (169 kph). Prediction models showed Julio weakening before it reaches the Hawaiian Islands early on Sunday morning and tracking about 150 miles (240 km) north of the archipelago. -- SPA 20:39 LOCAL TIME 17:39 GMT www.spa.gov.sa/w