Hurricane Katia headed north Thursday between the island of Bermuda and the East Coast of the United States, the National Hurricane Center said.In its 5 a.m. EDT update, the center reported Katia was packing sustained winds of 90 mph.A tropical storm watch continued in effect for Bermuda as Katia traveled north at 14 mph.Forecasters said Katia would probably bring one to two inches of rain to Bermuda.The Category 1 hurricane was expected to increase speed Thursday night with a possible turn toward the northeast, the hurricane center said.During the next few days, large swells generated by Katia will affect most of the East Coast of the United States, Bermuda and east-facing beaches of the Bahamas, forecasters said.The swells will probably cause life-threatening surf and rip current conditions, forecasters warned.