(CNN) A powerful winter storm is threatening parts of the United States with crippling freezing rain, sleet and snow, and experts are urging Americans to be prepared.
Make sure you've done the basics: Learn how to keep your pipes from freezing (for example, you can open cabinets in places like under sinks to let heat in or let faucets drip), test smoke alarms and carbon monoxide detectors, have extra batteries for radios and flashlights, charge electronics and consider specific needs of everyone in your household, like medication.
And ensure you have all the grocery supplies you need.
These kinds of storms -- and their aftermath -- can cut off heat, power or communication services. Because we don't yet know how severe the impacts will be and how long they will last, and amid supply chain problems that could further compound grocery shopping struggles this weekend, have at least three days' worth of food and water for everyone in your home, says Joann Sands, a clinical assistant professor in the School of Nursing at the University of Buffalo, who trains students in disaster and emergency preparedness.
Choose groceries that have a long shelf life, don't require cooking and are not too salty or spicy, because those foods mean you'll likely drink more water, the US Centers for Disease Control and Prevention recommends.
Here's what you should make sure to stock up on in your home.
Those include foods like energy bars and protein and fruit bars that don't need to be refrigerated or frozen, Sands said.
Dry cereal, granola, peanut butter, dried fruit and non-perishable pasteurized milk are also good to have as you hunker down.
Remember that the power may be out as the storm whips through your region, so have with you ready-to-eat canned meats, fruits, vegetables and canned juices as well as a manual can opener, according to Ready.gov.
Canned dietetic foods, juices and soups may be especially helpful for elderly or ill people, according to the Federal Emergency Management Agency.
If a can is swollen, dented or corroded, do not eat from it.
Though not essential, experts recommend you have comfort and stress foods on hand as you weather the storm.
Store at least three days' worth of water supply for each person in your household and for each pet, the CDC recommends. FEMA recommends storing at least one gallon of water for each person in your household for each day.
Unopened, commercially bottled water is the safest and most reliable water supply, the agency says. If it's store-bought water, make sure you check the expiration date.
Make sure you also have plastic bags on hand, as you can wrap perishable foods -- like cookies -- in there, and place them in sealed containers, according to FEMA.
If you're out of electricity and water, having paper plates and utensils can help you prepare and eat your meals safely, the CDC says.
When preparing, don't forget about babies and pets in the house.
Make sure you have enough supply of baby formula, as well as anything else an infant may need, like diapers, said Sands.
Be sure to also have several days' worth of supplies for pets, like medications and non-perishable foods.
(And maybe some treats, as storms can be stressful for them as well.)
Check that you have the hygiene products you need -- including feminine supplies, toilet paper, wet wipes, paper towels and hand sanitizer.
It's always good to have a disaster kit at the ready that's in a portable container near your home's exit.
Those should include: non-perishable foods and a three-day supply of water, a battery-powered radio and flashlight, extra batteries, a first-aid kit with a manual, sanitation items, matches in a waterproof container, a whistle to signal for help if you need to, clothing, blankets and sleeping bags, identification cards, credit cards and cash, paper and pencil, items to cover baby and pet needs and any special items like medications, contact lenses, glasses, hearing aids and activities for younger children.
Because of the ongoing Covid-19 pandemic, you should also include things like face masks.
It's important that you don't panic-buy and try and fill your fridge, Sands said.
"How are you going to be able to store this food if you don't have power?" Sands said, adding that stocking up on extra groceries can not only lead to wasted food but could hurt others that may not be able to find what they're looking for.
If your power goes out, keep refrigerator and freezer doors closed as much as you can, to avoid letting the cool air out. If unopened, your fridge will be able to keep food cold for about four hours, according to Ready.gov.
Throw out any perishable food -- like meat, poultry, eggs or leftovers -- that's been left in temperatures over 40 degrees Fahrenheit for more than two hours.
While in a winter storm you should try to minimize traveling as much as you can, to avoid getting stranded on the road. Make sure that if you do have to go out, you have a full tank of gas, Sands said.
It's also a good idea to have an emergency kit inside each one of your family's vehicles, in case you get stranded.
Here's what to pack in your car to stay safe.