(Reuters) -Online spending is expected to surge to $23.8 billion across U.S. retailers during a 96-hour Amazon Prime Day event this week, according to an Adobe Analytics forecast released on Monday, as shoppers seek strong discounts on back-to-school gear ranging from apparel to electronics.

Sales from July 8 to 11 are projected to rise 28.4% compared with the same period last year, the report said. Retailers recorded online sales worth $14.2 billion during the two-day Amazon shopping event last July.

"This is equivalent to two Black Fridays," Adobe noted, adding that budget-conscious consumers are adjusting their shopping habits by using generative AI to find deals and get an early start on back-to-school purchases.

Global trade uncertainties, fueled by President Trump's unpredictable rollout of tariffs, have unsettled consumer confidence and put businesses on edge ahead of the July 9 deadline for countries to negotiate trade agreements with the United States.

E-commerce giant Amazon.com has extended its sales window to 96 hours, up from 48, as competitors such as Walmart and Target launch their own promotions.

Shoppers are expected to take advantage of steep discounts to "trade up" to higher-ticket items such as electronics, sporting goods, and appliances, while opting for more affordable alternatives in categories like home and garden or groceries.

Clothing is forecast to see the deepest discounts at 24%, up from 20% last year, while discounts on electronics are expected to dip slightly to 22%, according to Adobe Analytics.

Sales of backpacks, lunchboxes, and college essentials-including headphones and computers-are also expected to increase.

The data firm expects Buy Now Pay Later (BNPL) usage to increase slightly during the Prime Day event, accounting for 8% of overall online spending compared to last year's 7.6% share.

Adobe's forecast is based on an analysis of 1 trillion visits to U.S. retail ecommerce sites, covering 100 million SKUs and 18 product categories.