A series of thunderstorms took Islanders by surprise Saturday, dropping hail and featuring a dramatic lightning show.

There was drenching rain in spots. — Ray Ewing

After a sunny, summery day, the weather system swept in from the northwest around 4 p.m., startling beachgoers, baseball players and boaters. There was thunder and pea-sized hail in some places, and more weather in the evening at around 8 p.m.

Cold air coming toward the Vineyard from Canada and moving over much warmer surface temperatures made for a volatile system, according to National Weather Service spokesman Bill Simpson.

“The surface heating is going and you get those puffy clouds, and once that convection works out it gets very unstable,” he said.

He said precipitation often starts out as hail, but usually melts before it reaches the surface.

In Edgartowwn the storm dropped hail. — Ray Ewing

A weather station monitored by Mark Lovewell in Vineyard Haven recorded a total of 0.08 inches for both storms on Saturday.

The National Weather Service Station Edgartown recorded a total of .33 inches.

Mr. Simpson at the National Weather Service in Taunton said while dramatic, the weather was not particularly unusual. He said the time of day, noticeable change from earlier weather and visibility made the storms more noticeable.

“It wasn’t a solid cloud cover, and you saw the thunderstorms,” he said. “They were really pretty.”