Hawaii’s governor has declared a state of emergency as one of the Central Pacific’s most powerful hurricanes on record approaches the archipelago. Hurricane Lane briefly reached Category 5 status—the highest-ranking—before weakening slightly to a still-powerful Category 4 storm with maximum sustained winds of 145 miles per hour. It’s expected to sweep just west of Hawaii’s Big Island later today, and authorities warn it could bring a year’s worth of rain to parts of Hawaii within just hours. The storm is the most powerful hurricane to threaten Hawaii in recorded history. Climate scientists say increased ocean temperatures from greenhouse gas emissions are driving more powerful storms like Hurricane Lane.