At 45 miles, you should have access to virtually everything in NY and NJ using my antenna. I don't really see many wind issues with my antenna at home other than the ones we cannot control, and there are many of them beyond our control.
This starts with the link from the studio to the transmitter sites that use microwave to send their signal to the transmitter due to tower or microwave dish movement, along with the issues in the reply I posted about transmit antennas being effected by the wind. I posted a picture of a slot type UHF channel 20 antenna on the trailer it was delivered on just to give you an idea of just how big they really are. This antenna weighs in at 8,000 lbs, and is 60 feet long, and I assisted in its installation (On the ground that is !!!)
If the station is using a live satellite feed such as MY-TV or ME-TV or THIS-TV, the satellite dish used to receive the feed can also be effected by the wind causing wind breakup. This may not even be a problem on your end at all, as there are so many variables involved in how the transmitter receives the programming from the studio.
If I were to send you an antenna, and it was attic mounted, and you still have the problem, then it could come down to an issue on the stations end that they need to address. You may even try to call the station and talk to the engineer and ask them if they may have any wind related issues that they are aware of. Another hint is that this is only happening on a few channels, and not all of them. If this was an issue with wind movement of your antenna, foliage or other local issues with your antenna, it would likely effect all of your channels, and not just some of them.
I always advocate outdoor mounting for best results, but not everyone can mount one outside as it should be done. Higher is always better, but attic mounting may be one way to rule out wind issues with your situation. If you still see the issue with an attic mounted antenna, you will then know almost 100% that the problem is on the broadcasters end. You can also likely rule out any effects from foliage since most everything is still somewhat bare in your area now, as it is here, and I am around 700 miles south of you.