Barren shelves at Long Island stores have contributed to growing fears of possible food shortages.

Five weeks after stores starting seeing an influx of customers preparing for the coronavirus, some shoppers are still having a tough time finding what they need.

Experts says manufacturers rely on a forecast based on a typical supply and demand model, but this pandemic threw that into a tailspin.

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"With a demand spike like we saw, that forecast goes out the window," says Hofstra management professor Dr. Kaushik Sengupta. "So essentially what has happened is that in such a short amount of time, you can't really match up to that spike in demand."

News 12 viewers weighed in on their efforts getting groceries, with a mix of frustration finding anything, to others getting almost all of what they needed.

There does seem to be a difference in what people say they're finding, depending on where they're going. Some viewers say they're much more successful at smaller, community-based stores rather than large chains.

Supermarket executives say their main focus is getting the items that are in highest demand. A statement from King Kullen says, "The system delivering food and products to supermarkets has not caught up with the overwhelming demand created by people being home, schools being closed and the surge in shopping that took place in the early days of the pandemic."