New York City retail stores are reporting especially strong sales for the Friday after Thanksgiving, historically known as “Black Friday,” both from local customers and visiting foreigners capitalizing on the weak dollar. National sales figures are up, too, with Chicago-based retail sales research group ShopperTrak RCT Corp. reporting a strong start for the inaugural weekend of the holiday shopping season.

ShopperTrak’s National Retail Sales Estimate reported over the weekend that sales on Black Friday increased 8.3% over 2006, nearly four percentage points higher than expected. The research group, which tracks more than 50,000 retail outlets across the country, estimated $10.3 billion in total sales over of the day. Black Friday, so called because the day’s shopping surge used to make stores profitable for the first time in the year, does not always predict strong sales throughout the holiday season. Still, speculators hope that these sales numbers indicate that American shoppers are less discouraged by high gas prices and the credit crisis than economists predicted.

Many American merchants have been struggling with flagging sales in recent months, likely a result of recent economic pressures. However, few of New York’s flagship retail outlets are reporting fewer sales, and the holiday shopping spirit here seems especially lively, retailers say.

“We didn’t see any indications of declining sales leading up to Friday,” a spokesman for J&R Music and Computer World, Abe Brown, said. “Sales have been strong all month.”

The vice president of public relations at FAO Schwarz, Lanette DiFalco, reported that as of this October, annual traffic is up 68% over 2006. She predicted strong sales for the holiday season. “So far in the month of November, traffic is 80% over last year,” she said.

Stores across the country often feed the buying frenzy on Black Friday by offering “door buster” deals to entice customers to line up long before business hours. New York retailers were no exception this year, offering sales and rebates that created lines snaking around corners and down blocks.

Consumer electronics were among the most sought-after holiday purchases over the weekend, with heavily discounted plasma televisions and digital cameras topping the list. Gaming consoles were big sellers, too. “The Nintendo Wii created a lot of excitement. It got people into the holiday spirit,” Mr. Brown said.

Unseasonably warm temperatures in New York on Thanksgiving and last weekend likely contributed to improved sales. In 2006, poor weather was blamed for reduced sales figures at the beginning of the holiday season. “We saw a lot more people coming in after the Macy’s Thanksgiving parade this year,” Ms. DiFalco said. Retailers also say purchases by European visitors are likely to help make up for any dip in holiday sales. FAO Schwarz is planning on opening its doors as early as 7:30 a.m. on some days to bring in trans-Atlantic tourists whose body clocks are not yet on New York time, Ms. DiFalco said.