Five days after the October snowstorm, more than 420,000 homes and businesses are still without electricity in Connecticut and tens of thousands in New Jersey are still in the dark.

Most of the outages remain in the central and northwestern part of the state, west of the Interstate 84 corridor —  where critical transmission lines connecting substations were damaged by downed trees, according to a spokeswoman with Connecticut Light & Power.

“We're still discovering the full extent of damage there, and now that we've got substations all back on line, we can test the wires and find out where the biggest problems are,” said Katie Blint of CL&P.

The company said it remained on track to restore power to most of its service coverage by Sunday night. Customers can call the company or log on to its website to see when they can expect to get their power back.

 Blint said the utility, the largest electricity provider in the state, had to bring in contractors from as far away as California and British Columbia, Canada, because neighboring states were inundated with repair work themselves.

In New Jersey, about 80,000 customers served by the state’s two major utilities remained without power as of midday Thursday, and the companies said they aimed to restore most service by midnight.