Hurricane Iselle weakened from a Category 4 on Monday to a Category 1 on Wednesday, but the storm could still be at hurricane strength with gusts of up to 90 miles per hour when it hits Hawaii on Thursday, according to the U.S. National Hurricane Center. Meanwhile, Hurricane Julio was upgraded from a tropical storm on Wednesday with maximum wind speeds of 75 mph and is following about 1,000 miles behind Iselle on a path toward Hawaii landfall by Sunday.

Julio Hurricane Julio was upgraded from tropical storm on Wednesday. Photo: U.S. National Hurricane Center

“Satellite imagery shows that Julio has become a little better organized, with multiple convective bands near the center and an eye possibly trying to form,” NHC forecasters reported. “The intensity is most likely going to be controlled by sea surface temperatures and nearby dry air . . . [but] none of the dynamical models forecast Julio to dissipate during the next 5 days.”

Iselle Hurricane Iselle's latest trajectory forecast. Photo: U.S. National Hurricane Center

This means Hawaii could be in store for its first-ever recorded hurricane double whammy. In 1982 the state was hit with a tropical depression followed by a tropical storm 10 days later. Kevin Roth, lead meteorologist at the Weather Channel, said a pair of cyclones hitting Hawaii in close succession is “unprecedented in the satellite era.”

A third hurricane, Genevieve, is meandering about 1,100 miles west of Hawaii, but its current path is northbound toward open water.

Weather Channel Hurricane Iselle (left) and Hurricane Julio are both Category 1 storms right now. Both are headed to Hawaii. Photo: The Weather Channel

Hawaii Gov. Neil Abercrombie is urging residents to plan for power outages and to stock up on water. Local emergency officials are also informing residents of shelter locations. A hurricane warning is in effect for Hawaii County, which covers the largest island in the chain that’s home to about 185,000 residents. Neighboring Maui County, a four-island chain with about 152,000 residents, is under a tropical storm warning.