Winter Storm Fern will hit Maryland tonight, bringing heavy snow, ice and dangerously low temperatures that are already disrupting travel and shuttering colleges and businesses.

Here’s what to know:

⛄ Snow, ice, cold: Snow will move into Maryland this evening with a winter storm warning going into effect at 11 p.m. Forecasters say icy conditions and extreme cold will linger into early next week.

🛒 Pre-storm prep: Grocery shoppers have emptied shelves. State and local agencies have been busy preparing to treat roads and mitigate emergencies ahead of the snow.

✈️ Closures and cancellations: Twelve thousand flights have been canceled nationwide. Libraries, recreational facilities and some universities have already announced closures. One weatherman thinks schools will be closed all of next week. If so, that could extend the school year for some Maryland students.

🔌 Power outages: The storm will bring ice and the potential for power outages. Here’s what to know if your power goes out.

❄️ Cold weather safety: If you plan to shovel snow or be out in the cold, here’s how to protect yourself.