If you’ve been putting off the start of the semester Whole Foods run, it may be time to get it done.

A “potentially historic” snowstorm could hit D.C. this weekend, Capital Weather Gangreported. The snow is predicted to begin during the day on Friday, with the worst conditions continuing overnight and into Saturday.

The Capital Weather Gang’s forecast models predict anywhere from one to 20 inches over Friday and Saturday, with a most likely scenario of a “severe” snowstorm with near-blizzard conditions and one to two feet of snow. The National Weather Service has declared a “high” winter-storm-threat level.

The mix of heavy snow, low temperatures and high winds could mean road closures, travel delays and power outages, according to Capital Weather Gang.

No official announcement has been made by the University about the upcoming storm.