The news: Walmart spent this summer describing, in blog posts and a run of interviews, how it uses AI to keep goods moving through severe weather. It forecasts what a storm will sell, simulates the damage on a virtual copy of the network, and moves inventory before the weather arrives.
Indira Uppuluri, Walmart’s senior vice president of supply chain technology, described the system in a July interview. “We bring a lot of signals together to simulate what it would mean for us and what the impact to our stores and customers is going to be,” she said.
For proof, the company points to Winter Storm Fern in January. By its own account, it staged supplies like ice melt and water “several days earlier than was previously possible.” It also rerouted hundreds of thousands of items to secondary distribution centers before the snow started, as reported by Fortune.
But Walmart has not published an in-stock rate, a closure count or any comparison against a prior storm.
Billion-dollar US weather disasters have meanwhile climbed from about three a year in the 1980s to about 20 a year over the past decade, according to Climate Central. The group continues the count NOAA retired in 2025. Part of that rise, though, reflects growth in the value of property sitting in harm’s way.
How it works: The system has three parts, as Walmart describes it.
It predicts demand. Forecasting models read weather forecasts alongside years of sales history, so Walmart knows what a storm sells. Planalytics, a firm that sells weather-demand analytics, estimates sales of storm goods like ice melt and shovels can jump 50% to 500% before the weather arrives.
It tests the network. Walmart keeps a digital twin, a virtual copy of its distribution centers and transportation routes. Teams use it before a storm to ask what if a warehouse loses capacity, or deliveries run late, or demand doubles, then move inventory to match the answers.
It reacts during the storm. A fulfillment engine recalculates delivery routes for online orders as roads close, and tracking systems update customers' delivery windows automatically.
Walmart says the software makes recommendations and people make the decisions, and one of those people has since built a tool of his own on top of it.
Jeff McIntosh, a transportation director at Walmart Canada, spent 12 to 14 hours manually rerouting trucks during a Montreal ice storm in March. So he used AI coding tools to build an agent that checks 10-day weather forecasts against live highway closures, ferry cancellations and carrier schedules.
“The goal is to understand the impact early enough to give our supply, transportation and store teams options,” he said, in a profile published by Walmart’s own tech blog.
Some runs point past the storm they were built for. “As we run through these simulations, sometimes we realize maybe we can run our network slightly differently,” Uppuluri said. “Maybe we can configure it differently.”
The backdrop: In 2004, long before the AI, Walmart’s then-chief information officer, Linda Dillman, had analysts mine sales data from one hurricane to stock stores for the next. They found that strawberry Pop-Tarts sell at “like seven times” the normal rate before a hurricane, and that beer sells most of all.
A year later, Katrina made the company's emergency operations center famous. The center started planning five days before landfall and staged trucks outside the strike zone. It then shipped nearly 2,500 truckloads of supplies in three weeks, according to a case study by the Independent Institute.
The study argues the company outperformed the federal response. The work itself was still manual, though: the storm knocked out Walmart’s inventory systems, so the response ran on satellite phones and managers’ judgement.
Both rivals still work that way. Home Depot puts more than 100 people in its center during a storm, and Lowe’s activates its own ahead of hurricanes.
In February 2021, Walmart’s emergency center watched the Texas cold coming for a week, but the freeze still closed 651 Walmart locations, its largest cluster of closures since Hurricane Irma. Forbes attributes those closures to the grid failure that left 4.5 million Texans without power and to water-main breaks that left stores without water pressure.
By the following year, Walmart was describing something different. Hurricane Ian knocked a southwest Florida distribution center offline for about seven days, and the network rerouted around it while handling the post-storm rush.
“Not only was a node offline, we also had a lot more demand because people shop a lot more after a weather event,” Srini Venkatesan said afterward. Venkatesan was the Walmart tech executive then overseeing the systems.
The moves are still the 2004 ones: stock what sells, pre-position, reroute. What changed, on Walmart's telling, is that they start days ahead, run store by store, and can be rehearsed in simulation first.
Walmart also kept the command room. It opened a Global Security Operations Center in Bentonville in August 2025, almost exactly 20 years after Katrina. It runs around the clock with meteorologists on staff, monitoring weather and risk worldwide, local station 5NEWS reported from the ribbon-cutting.
The counter: UPS ran its own weather desk long before Walmart described this system, but last year it gave that up. About five full-time meteorologists worked out of the carrier's main Louisville hub, reading global weather patterns and steering planes and trucks around them. CEO Carol Tomé had called the in-house team a strategic advantage at an investor day in 2024.
Then, in 2025, UPS moved its forecasting to The Weather Company, which runs weather.com and the Weather Channel app, Bloomberg reported that August. UPS had already handed its pension investment work to Goldman Sachs, and it had outsourced parts of its tech support too.
UPS did not say why it made the change. But the move came while the company was cutting harder than at any point in its history: 20,000 operational jobs, and half its unprofitable Amazon volume gone by mid-2026. Its stock was down 31% that year through late August, while the S&P 500 rose 10%.
What’s unclear: Walmart is the source for nearly all of this account. The blog posts, the digital twin description, the Fern account and the employee profile are all Walmart’s, and every executive quoted works there.
Weather-driven demand forecasting is also a product other firms sell, including Planalytics. Walmart is the retailer talking about this in public, which is not the same as being the only one doing it. And the command centers at Home Depot and Lowe’s may run comparable software.
The 2021 freeze and the 2022 hurricane also happened in different regions and failed for different reasons, and Walmart has released no metric linking either to the system.
What’s next: Hurricane season peaks in September, weeks after the summer’s blog posts and interviews. Walmart has published no outcome number for the system so far.
