Workers were kept busy clearing roads and debris from parks on Maui after a windy thunderstorm swept across the island. The Maui News/Gary Kubota

Maui residents experienced widespread power outages affecting some 21,892 customers Friday, as a thunderstorm crossed the island with heavy rain as well as snow on Mt. Haleakala.

According to Maui Electric, there were 19 outages that affected Kahului, North Shore, South Maui, Upcountry, Wailuku and West Maui. By noon Friday, power had been restored to about 16,000 customers in parts of South Maui, Makawao, West Maui and Central Maui.

Helicopter and ground crews were assessing the damage before restoring power safely to the remaining 5,000 customers, the utility said Friday afternoon.

“As damage assessments continue to be conducted in the areas where it is safe to work, customers should plan for potential extended outages as all lines must first be inspected to ensure there is no damaged equipment before it can be safely restored,” according to Maui Electric.

Maui County officials said the storm forced the closure of some parks and roads including Okolani Drive and South Kihei Road, which remained closed as of noon Friday.

Also, trees blocked both lanes on Naalae and Waipoli roads Upcountry, as well as Mapu Drive in Maui Meadows

County parks and recreation were closed due to debris, damage and power outages, including Central Maui Regional Sports Complex, Coach Spencer Shiraishi Memorial Pool, Keawakapu Beach parking lot, Kīhei Aquatic Center; Kīhei Community Center.

Duration of closures will be provided as damage assessments are made.

The new Kula Ballfield Park’s restrooms will remain closed this weekend due to a main water line break, the county said. Portable restrooms will be made available.

On early Friday morning, the National Weather Service said severe thunderstorms were located along a line extending from Waiehu to near Kipahulu, moving southwest at 10 mph. The hazard was in the 60 mph wind gusts, along with flash flooding.

On Haleakala, some snow fell with most of it ice at the top, Haleakala National Park spokesperson Sara Harper said.

Harper said there was a downpour of rain and solid ice on the road and debris on the road.

She said the gates to the park were closed at about 4 a.m. Friday. Work was done to clear the debris, and the park reopened that same day at 1 p.m.

“It’s all passable,” she said.

The park is resuming regular hours Saturday, including its sunrise reservation schedule.

For more information on our power restoration steps, visit hawaiianelectric.com/safety-and-outages/storm-center/storm-restoration-process.

To report any downed power lines, Maui customers may call Maui Electric’s Trouble Line at 1-808-871-7777.

Maui Electric said for the public’s safety, always treat downed power lines as energized and dangerous, and stay at least 30 feet or more away from the lines.

Customers may call 911 to report dangerous situations such as downed power lines or sparking electrical equipment. Please help us keep phone lines open for emergencies.