A spring storm that brought gusty winds, rain, snow and sleet led to thousands of power outages Thursday, more than a dozen school delays and flooding in some areas of the state.

The wintry mix overnight and into the morning made for slippery roads across Connecticut, as temperatures in some areas dipped down into the low 30s, according to the National Weather Service. The mixed precipitation followed multiple days of rainfall and already saturated conditions in much of the state, leading to trees coming down and closing some roads.

According to the state Department of Transportation, Route 16 in Colchester, Route 219 in New Hartford, Route 44 in Ashford and Route 14A in Sterling were closed Thursday morning of because of a trees down into wires. Route 43 in Cornwall was closed because of a tree down in the road, the DOT said.

A coastal flood warning remained in effect in the southern Middlesex and New London Counties until the late morning hours Thursday, with “up to 2 feet of inundation above ground level expected in vulnerable areas near the waterfront and shoreline,” according to the NWS.

“Minor to locally moderate flooding possible in the most vulnerable locations near the waterfront and shoreline early Thursday morning,” the NWS said.

“Some roads and low lying property including parking lots, parks, lawns and homes/businesses with basements near the waterfront will experience shallow flooding.”

The weather service also issued a flood warning for the Connecticut River, affecting Middlesex County until the evening hours.

“At 7.0 feet, flooding is likely in the vicinity of Meadow Road, Route 17A, in the Gildersleeve section of Portland,” the NWS said. “A portion of this roadway will likely be closed. This includes the Exchange Club of Portland Fairgrounds. Boating interests should prepare for a period of swift river flows during this period.”

According to Eversource, more than 7,000 customers in Connecticut were without power at one point in the morning hours. That number was down to 6,538 as of about 8 a.m., according to Eversource — which serves just over 1.3 million customers throughout the state.

These included 1,131 customers in Stafford, 659 in Vernon, 392 in Mansfield and 306 in Greenwich.

According to the NWS, a wind advisory remained in effect for northern portions of Connecticut until 2 p.m. Winds between 25 to 30 mph were expected, with gusts up to 50 mph.

“Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result,” the advisory said.

“Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution.”

Nearly 20 public school systems throughout Connecticut were operating on a two-hour delay Thursday, including those in Avon, Farmington, Simsbury, Stafford, Suffield, Windsor Locks, Tolland, Torrington and other towns.