If you’re out late tonight and hear loud aircraft overhead, don’t be concerned: The North American Aerospace Defense Command will be conducting an exercise between midnight on Tuesday and 2 a.m. early Wednesday morning.

The exercise, known as Falcon Virgo, involves a series of training flights to refine operations and test the National Capital Region Visual Warning System. Civil Air Patrol aircraft, Air Force F-16s and a U.S. Coast Guard HH-65 Dolphin helicopter will all take part.

Should the weather prove problematic, the exercise will be held on Wednesday evening and into early Thursday morning. If bad weather persists, officials could postpone or cancel the exercise. For what it’s worth, the Capital Weather Gang forecasts rain on Tuesday night and rain, sleet and potential snow on Wednesday night.