A number of grocery stores across North Carolina, and the United States are dealing with empty shelves. Here's why it's happening.If you've been grocery shopping recently, you more than likely have seen an empty shelf with limited to no food items.So why is this happening -- again?There are several factors.WXII 12 News stopped by several grocery stores in Winston-Salem to understand what some businesses are currently dealing with.We stopped by Harris Teeter in Winston-Salem, and there were several bare shelves, including within the chip aisle, water aisle, and bread aisle.A Food Lion location, not too far away, had a similar scene.Shelves within the toiletry aisle were bare. In another aisle over, much of the medicine that was offered was in very limited supply, and the juice aisle had several rows of empty shelves.WXII 12 News also stopped by Publix, a few minutes away, and we saw more empty shelves -- certain meats, cereal, juices, and frozen food products.FOOD INDUSTRY ASSOCIATION (FMI):WXII 12 News talked with Heather Garlich, Senior Vice President, Communications, Marketing and Consumer/Community Affairs with the Food Industry Association last week. The organization works "with and on behalf of the entire industry to advance a safer, healthier and more efficient consumer food supply chain," according to its website. Garlich shared the following statement:"While supply chain bottlenecks and labor shortages have impacted the food retail industry’s ability to bring some products to shelves, winter storms and severe weather could cause even further disruptions. These weather events can delay shipments, damage crops, and prevent some products from reaching the shelves. For example, winter storms that impact the I-95 corridor – a major South-to-North artery for the grocery supply chain along the East coast – can disrupt how quickly trucks are able to arrive and unload products at your local supermarket," she wrote.She added, "when you consider that consumers tend to go to the store to stock-up in advance of extreme weather events, you create a situation where your grocer may not be able to re-stock their shelves as quickly as usual. However, rest assured that grocers around the U.S. are working to ensure that shelves get stocked and prices remain low as possible, so families have access to necessities."FACTORS DRIVING EMPTY SHELVES:Leaders with FMI said there are several factors that drive the empty shelves, including:Labor shortagesTransportation shortagesExtreme weatherAvailability of ingredients and materialsEquipment availabilityTransportation logisticsCOVID-19Gas pricesResources to watch over children (ex: daycare centers, etc.)According to a survey conducted by FMI leaders, 80% of responding retailers said their inability to attract and retain quality employees is having a negative impact on their businesses. FMI leaders said, the truck transportation industry lost 6% of its 1.52 million workers, according to data from the Bureau of Labor Statistics.As of July 2021, the industry was still more than 33,000 jobs short of pre-pandemic employment levels. This is on top of the nation already facing a shortage of more than 60,000 drivers as of 2018, according to the American Trucking Associations.Officials with FMI said a combination of lack of staffing and a driver shortage has created backups -- from eight to 12 weeks behind schedule. To address and attempt to offset the labor challenges of the past 18 months, a number of retailers have offered a combination of higher wages, bonuses, improved benefits, flextime, and training and skills development opportunities.FOOD-DELIVERY DRIVER:WXII 12 News ran into Michael Hairston, a full-time food-delivery driver, at a grocery store in Winston-Salem Thursday. He said he's seen many empty shelves while working for more than a year.He added, the issue has created challenges for both workers and customers. He said many items on his customer's grocery list are sometimes not available, and that forces many workers to over-communicate with the customer, if they're available at the time, to find a replacement item. He said this happens to a number of items on one customer's list.He added, some customers he's worked with were not aware of the significance of the supply chain issue."It can make an order that’s simple or order that can be done in 30 minutes of shopping, it can make it, it can cause it to take longer. Meaning we got to communicate with the customer more. We got to replace a lot more. Sometimes we don’t have to, depending on if it’s available or not," said Hairston.SUPPLY CHAIN MANAGEMENT EXPERT:WXII 12 News talked with Haresh Gurnani, a supply chain management professor at Wake Forest University who's been working in the field for more than 30 years, to better understand the economic impact of the global supply chain issue.Gurnani said he agrees with the Food Industry Association's analysis regarding the factors that are driving the empty shelves.He said customers' behavior also play a part into the situation."This has influenced our human behavior," he said. "Our purchasing behavior. It’s not a surprise each time we go to the grocery store, we encounter prices of essential items going up, and now when you superimpose a product shortage, the human psychology gets affected, whereby we tend to make larger purchases than we really need at times. That further makes the problem more severe."When will shelves return to normal?Gurnani said there are several factors that play into the answer. First, he said the winter weather has played a large role in recent days. He said, "we’re in the early stages of winter. So I expect the weather related interruptions, which are entirely unpredictable, so in North Carolina, I imagine in February. But we may get snow in March. But we’re clearly not equipped for severe weather disruptions here."Government subsidies are another factor, he added. He said, "there’s only a certain amount of time you can rely on your savings and government assistance. At some point, workers will have to enter the work place."NBC NEWS: According to a recent NBC News report, Doug Baker, vice president of industry relations for the Food Marketing Institute, a trade group, said the latest Covid-19 variant and the bad stretch of winter weather have made the supply chain situation worse. He said he remained hopeful things would normalize again once the country got through the omicron surge.“Supply chain constraints and shelf conditions will continue to have their ebbs and flows, but maybe by the back half of 2022 we’ll start seeing some normalizing of the supply chain,” he said. “You have to put an asterisk on that because we can get another variant and another spike in cases, and we’re starting to see really abnormal weather patterns.”Rain and tornadoes in the spring followed by an active hurricane season could have a heavy effect on the country’s supply chain, Baker noted, and the industry is still contending with how best to make itself attractive to workers.The number of people who voluntarily quit their jobs surged to 4.5 million in November, the U.S. Department of Labor’s monthly job openings and labor turnover survey said last week, indicating Americans are increasingly confident they can find better opportunities in the labor market.