I can hear a low bass grumble of that wind, for just a couple seconds.
How does that compare to the lowest note you played? A high-pass filter should be able to take-out the low-frequency noise. I don’t think of a harp as a “bass” instrument, but apparently it has a very wide range. Here is a chart of [u]musical note frequencies[/u] to help with the filter cut-off frequency. . Even if some of the lowest notes are filtered-out, their harmonics will remain and it might sound better than the noise.
You might be able to filter just the parts where there is noise, but that could create a “glitch” where the filter kicks-in and kicks-out.
The Noise Reduction effect (filter) does require a sample of noise-only so it knows what to filter. And, it often has artifacts (side effects) if the noise is bad or intermittent… It’s not very good with wind noise.
I’m making my first outdoor harp music video.
If you want the absolute best results, re-record the in a “studio” or “music room”. (You’ll need to listen to the existing “backing track” with headphones to keep in sync.)
…Acoustic solo instruments (or vocals) are “difficult” because any noise is noticeable.
Low Rolloff for Speech was designed to get rid of most rumble and low pitched sounds (wind, trucks driving by, thunder, bad USB microphones) without affecting human speech very much. The two sounds do overlap a bit. Somebody with a ballsy announcing voice will find some of his syrupy tones reduced. Some other methods must be found to deal with that.
This can still get messed up. If the wind created sound that drove the blue waves on the timeline all the way up, that will create overload distortion. That is very different and difficult to remove. Turn on View > Show Clipping. Look for red marks in the timeline.
Turning loose a good quality microphone outdoors is fraught with concerns.
That thing on the end of the boom is the microphone fuzzy covering to help guard against wind noises. In the industry, it’s known as a “dead cat” for obvious reasons.
The goal is to do nothing at all to the desired sound, but eliminate wind and rumble. Those do very well. You can certainly get foam wind screens that work, too, but dead cats have a firm place in the audio people’s toolkit.