PORTLAND, Maine (AP) — Tens of thousands of homes and businesses remained without power in New England on Saturday following powerful thunderstorms, and more rough weather was on the way.

Thunderstorms hit the region hard on Friday and forecasts called for more rain and heavy wind Sunday and Monday. More than 40,000 customers in the six-state region were without power after Friday’s storms.

The majority of those customers were in Massachusetts, where more than 25,000 customers lacked power in Essex County, which borders New Hampshire. The state had about 35,000 customers without power in total.

More than 3,000 customers also lacked power in Maine and Vermont. Power authorities in New England said they were working to restore power, and communities were also responding to wind damage that toppled utility poles and damaged homes and vehicles in some areas.

The storm resulted in wind gusts of more than 55 mph as well as heavy rainfall, tree damage and downed power lines, said National Grid, an electric utility serving the Northeast.

National Grid described the storm as “fast-moving” in a statement and said the outages were especially heavy in central and northern Massachusetts. The utility said it’s communicating with local officials and first responders about the possibility of more bad weather in the coming days.

“National Grid has secured additional crews and personnel across Massachusetts to repair the damage caused by this storm,” said Tim Moore, vice president for electric operations for New England. “We are currently working to assess the damage, address public safety and will be working to restore power as quickly as we safely can.”

National Grid said it was supplementing its own crews with 50 additional ones to respond to the weather damage. The crews will include forestry workers as well as damage assessors, overhead line workers and others, the utility said.

The New England states were also coping with high temperatures for September, and some schools had canceled classes or after-school activities. High temperatures were exacerbated by power outages and the lack of air conditioning. Boston opened cooling centers.