A sprawling winter storm is set to hit half of the country this weekend, and millions of people are bracing for delays and dangerous conditions.

• The big picture: What we do to prepare before the storm lands can make a critical difference in helping us — and our neighbors — get through it safely.

Zoom in: Here are some steps you can take to get ready and help others do the same — from buying supplies to donating blood.

• These tips are especially important if you live in an area that doesn't typically see severe winter weather and could be dealing with the effects of the storm for days.

🩸 Consider donating blood: America's blood supply is facing a critical shortage, and the storm could exacerbate the issue, Axios' April Rubin reports. The Red Cross said blood donations were down 35% nationally in the past month.

• "[R]ight now, the perfect storm of a long holiday season, record flu activity and winter weather are all impeding donation efforts," says Courtney Lawrence, executive medical director for the Red Cross. The ongoing shortage is especially serious for types O, A negative and B negative.

🛒 Buy the essential groceries: Stock up on a week's worth or more of bottled water and non-perishable items in addition to your normal groceries. Think beans, peanut butter, cereal and protein bars.

• Plus, make sure you pick up prescription medications before the storm hits.

💛 Lend a hand: If you have neighbors who are elderly or who have young kids, offer to pick up some groceries for them when you do your pre-storm run.

• If you have trouble getting around, ask a neighbor or friend to help stock your fridge and pantry.

📱 Get on the group chat: Collect neighbors' numbers if you don't already have them, and start a text chain to check in on folks throughout the weekend.

• Use the chat to share resources and to offer help de-icing and shoveling for neighbors who are older or have disabilities.

🔌 Prepare for power outages: Charge your devices and have extra batteries on hand in case you unexpectedly lose electricity during the storm.

• Worthy of your time: Snow survival 101, with tips from Axios reporters across the country

Reader Bonnie Datta snapped this brilliant sunset on Sunday from the Cowell-Purisima Coastal Trail off California's Highway 1.