(Updates with new quotes, details throughout, officials say Pennsylvania Turnpike reopened, 27 injured )
By Barbara Goldberg
NEW YORK, Feb 14 (Reuters) - The U.S. East Coast was blasted by the end of a four-day winter storm on Friday, freezing sales of Valentine's Day flowers and sweets but revving up snowmobiles and ski areas desperate to salvage a lackluster season.
As the storm blew out with a last salvo of thunder snow and lightning, the death toll rose to at least 20, including a 36-year-old pregnant woman killed by a snow plow in a Brooklyn parking lot. Her baby boy remained in critical but stable condition, a New York City Police spokeswoman said.
Snowfall measured 28.5 inches (72.3 cm) in Pilot, Virginia, about 200 miles (321 km) west of Richmond, said Chris Vaccaro, spokesman for the National Weather Service. A new storm system was on its way, expected to dump up to 3 inches (7 cm) on the East Coast into Saturday, he said.
Across the South, hundreds of thousands of people were still without power on Friday as the result of broken tree limbs stressed by heavy snow and thick layers of ice falling onto power lines. South Carolina customers may not be back to normal service until late Sunday, said Duke Energy spokeswoman Jennifer Jabon.
The Pennsylvania Turnpike was shut for more than seven hours while it was cleared of twisted metal from up to 50 vehicles in multiple accidents that injured 27 people, said Renee Vid Colborn, a spokeswoman for the Pennsylvania Turnpike Commission. The injuries were not life-threatening, she said.
About 1,500 U.S flights were canceled and roughly 4,700 more were delayed by midday on Friday, said flight-tracking website FlightAware.com.
The timing of the storm - Valentine's Day and at the start of the Presidents Day long weekend - was exasperating for florists and other vendors whose biggest business comes on the lovers' holiday.
But outdoor enthusiasts like dog sled guide Laura Bedortha of Husky Works Mushing Co in West Wardsboro, Vermont, were thrilled.
In Jackman, Maine, up near the Canadian border, Bishop's Store welcomed a steady stream of snowmobilers lining up for gas and breakfast sandwiches.
"This storm couldn't have come at a better time," said owner Lorraine Levesque.
The $350 million dollar snowmobile industry, which also does its part to fill hotel beds and restaurants, desperately needed the snow in a winter marked by freeze-thaw cycles in January and more rain than snow.
"This is as good as it gets before the vacation week," said Bob Meyers, spokesman for the Maine Snowmobile Association.
His sentiments were echoed in the online ski report posted by The Waterville Valley Resort in New Hampshire, which advised: "Forget whatever it was you were supposed to do this weekend and make your way up here."
And no snow enthusiast said it better than kindergartner Jack Mension, 6, sledding in Philadelphia's Clark Park on his second canceled school day.
"You can fly in the air!" Jack squealed as he zipped down the frozen hill.
Snow days troubled parents scrambling for childcare and school administrators who had to look at ways to extend the school calendar into summer to make up for lost classroom time.
The white stuff made Valentine's Day gift vendors see red. The number of flower deliveries that Luis Martinez made for employer Langdon Florist in downtown Manhattan were slashed in half compared with last year.
"The economy is doing better this year, but business is down because of the weather," he said, navigating pools of melting snow while carrying a bouquet of roses.
Darryl Rallis, 49, a third-generation wholesale flower vendor in New York, estimated he has sold a quarter of the flowers he normally sells on Valentine's Day, typically the year's biggest single day sales for florists, according to the Wholesale Flowers and Florists Association.
The chill was felt all the way to Colombia and Ecuador, which are the major suppliers for Cupid in America.
"The problem is Washington and places like that which are affected by consumers staying indoors," said Jairo Cadavid, spokesman for the Association of Colombian Flower Exporters, Asocolflores.
Valentine's Day flower exports to the United States from Ecuador are down between 12 percent and 14 percent from last year, said a spokesman for the Association of Flower Producers and Exporters, Expoflores.
Flour was flying at Carlo's Bakery in Hoboken, made famous by the popular American reality show Cake Boss, as bakers scrambled to meet requests for sweet somethings a day after the storm closed all of its four locations.
"We're working twice as hard today to meet the demands of yesterday," said bakery spokesman Adam Bourcier.
Friday's blue skies and temperatures in the 40s in the New York City area belied a previous night of unusual thunder snow and electrical storm in New Jersey. A bolt of lightning struck a Spirit Airlines plane flying from Fort Lauderdale, Florida, but it was able to land safely at its destination, Atlantic City International Airport, said airline spokesman Jim Lynde.
In Georgia, majestic trees that have grown tall during typically milder winters fell victim to the harsh weather. It was estimated that 5 million of the state's 25 million acres of forestland were damaged by the storm, said James Johnson, forest management chief with the Georgia Forestry Commission. (Additional reporting by Chris Francescani and Marina Lopes in New York, Dave Sherwood in Maine, Daniel Kelley in Pennsylvania, David Jones in New Jersey, Karen Brooks in Texas, Harriet McLeod in South Carolina, Richard Weizel in Connecticut, David Beasley in Georgia, Colleen Jenkins in North Carolina, Peter Murphy in Colombia and Alexandra Valencia in Ecuador; Editing by Gunna Dickson)