The coronavirus is clouding "Black Friday" much as it has overshadowed 2020 in general, but some leading experts still expect strong overall sales even as shopping patterns are altered.

The more bullish case for the holiday shopping season cites robust demand for bigger-ticket items such as home improvement projects, new computers and home fitness machines as more people work from home and e-commerce grabs an ever-increasing share of the overall market.

Malls were open for business as usual on Friday, but there were early indications that the day-after-Thanksgiving crowds were much more sparse this year as more consumers opt for e-commerce or for curbside pickup options because of the virus.

E-commerce sales on Thanksgiving reached a new record this year, rising 21.5 percent to $5.1 billion, according to data from Adobe.

The National Retail Federation projects a 2020 jump of between 3.6 percent and 5.2 percent in overall holiday compared with the year-ago season.

The trade group points to optimism over Covid-19 vaccines and says many consumers have available cash from an appreciating stock market, a strong housing market and disposable income that would otherwise have gone to travel and entertainment.

"Given the pandemic, there is uncertainty about consumers' willingness to spend, but with the economy improving most have the ability to spend," said Jack Kleinhinz, chief economist of the National Retail Federation.

But this outlook may understate the impact from elevated unemployment levels in the United States, exacerbated by Washington's inability to produce another round of fiscal support for struggling families.

An even bigger source of uncertainty is the coronavirus itself, which has been spreading quickly in much of the country, spurring fresh restrictions in some cities and dampening the holiday mood overall.

CFRA Research projected that 2020 would be the first holiday season of non-positive sales growth since 2008, with sales roughly flat. Last year sales rose 4.4 percent.

The projection rests on a so-called "K"-shaped economic recovery, with higher-income consumers able to splurge on bigger items and other consumers struggling to make ends meet.

There are some wildcards in the forecast. Sales could benefit if Washington comes through with stimulus soon, but would weaken further if there are widespread stores shutdowns because of Covid-19 spikes.

Among those in the less fortunate category, "people might be spending just on essential items as they tighten their purse strings," said CFRA Research analyst Camilla Yanushevsky.