The same snowstorm that grounded airplanes, shuttered hundreds of schools and emptied the region’s streets Thursday somehow left the lights on throughout the Washington region.

In recent years, similarly colossal storms have severed power to hundreds of thousands of homes and businesses, leaving them without heat or air conditioning, shutting off televisions and darkening streetlights. Violent thunderstorms in June 2012 cut power to more than a million customers in the region. But by mid-afternoon Thursday, fewer than 500 outages were reported in the Washington area, including 390 in Frederick County.

Power company officials said the relatively smooth day was a combination of planning and luck.

“We were prepared, but Mother Nature just was good to us,” said Priscilla Knight, a spokesman for NOVEC, which has 150,000 customers in Northern Virginia.

The snow that blanketed the region was “lighter and fluffier” than what was forecast, Knight said. Heavy, wet snow or freezing rain is more likely to bend and break tree limbs, endangering power lines. Strong winds are another dangerous element that did not factor into Thursday’s storm.

The biggest storm of the season dumped a thick snow blanket on the Washington area overnight. This video captures the snowfall from 7 p.m. Wednesday to 9 a.m Thursday. (Jeff Simon/The Washington Post)

As a result, the Virginia-based company had exactly one customer without power at 9 a.m. Thursday, more than 12 hours into the storm.

Officials said they were still monitoring weather reports and were predicting more precipitation Thursday night, but some said they did not expect the storm’s second wave to be as strong.

By mid-afternoon Thursday, the extra crews from Oklahoma, Arkansas, West Virginia and Louisiana that came here to assist Dominion Power already had been redirected to help sister companies in South Carolina and Georgia, where power outages were pervasive.

Tom Morris, a spokesman for Dominion, which serves 2.4 million customers in Virginia and North Carolina, said the area “clearly dodged a bullet” by getting the dry snow.

The utility company's biggest storm-related outage was the result of a traffic accident, Morris said. The company reported that 2,000 customers in Virginia lost power late Wednesday after a car hit a utility pole in McLean. Power was restored about four hours later, he said.

Pepco, which has nearly 800,000 customers in the District and in Montgomery and Prince George’s counties, reported no outages by mid-morning Thursday. By 8 p.m., about 4,000 customers were without power.

George Nelson, chief operating officer for Pepco Holdings Inc., said the limited disruptions were partly a result of an aggressive “vegetation management” program the company has undertaken the past three years.

Crews trimmed trees along 7,000 miles of power lines and also replaced poles and wires. The upgrades were a response to widespread outages in 2010 from “Snowmageddon” and again in January 2011, when some customers were without power for several days.

Aaron Koos, a spokesman for Baltimore Gas and Electric, which has 1.8 million customers in Baltimore and Eastern Maryland, also credited the company’s efforts to trim trees and replace lines over the past several years.

BGE officials said that more than 1,600 line workers and support staff were mobilized before this week’s storm — 500 of the line workers coming from 11 states.

Since the storm began, the utility restored power to 1,400 customers, most of them outside the Washington region.

By Thursday afternoon, fewer than 55 BGE customers in Howard, Anne Arundel and Montgomery counties were without power.

Many area residents, fearing outages, also took pains to prepare for the storm.

Marsh and Lynn Pierce, of Middleburg, Va., made sure to buy extra kerosene for their portable heater and fetch the dusty, cobweb-covered generator from the barn.

The effort was all for naught, Marsh Pierce said, because they didn’t lose power.

“It’s only when you’re not prepared that you lose power,” he added.

Pierce said he considers the generator to be like an insurance policy. In the five years since his family bought the generator, it’s been used once, Pierce said, and only briefly at that.

“I hooked it up and made coffee,” he said. “That’s it.”

T. Rees Shapiro contributed to this report.