Severe thunderstorms are possible across the Bay State on Friday, as National Weather Service forecasters warn of hail, lightning, strong wind gusts and torrential rainfall.

A “Severe Thunderstorm Watch” has been issued for much of Massachusetts until 8 p.m. The only parts of the state not in the watch zone were southeastern Massachusetts, Cape Cod and the Islands.

The forecasters were warning of the chance for ping-pong size hail, frequent lightning strikes, wind gusts up to 65 mph, and heavy rain. With the ground already so saturated from recent rainfall, some localized flooding will be possible.

Early Friday afternoon, a strong thunderstorm was being tracked in the Berkshires. The storm had 40 mph winds and penny size hail, along with torrential rainfall.

Meteorologists warned that the strong winds could spark minor damage, such as downed branches.

“Get indoors when you hear thunder,” the National Weather Service wrote. “Do not resume outdoor activities until at least 30 minutes after the storm has passed. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. For your safety, go indoors or to your vehicle.

“This storm may intensify and become severe,” NWS added. “Stay tuned to your local media for updates and possible warnings.”