I did a serious amount of research when installing our Over-the-air TV setup. There are many factors that interact with your reception. But my main question since things get worse with wind is do you have trees near by?
Your single reception is greatly affected by stuff right around it. Wind moving branches can seriously affect this. in fact, I pick up on my my main channels by not pointing directly at it. (there is a large tree directly in front of mine)
How to determine tv station locationhttp://www.antennaweb.org
Also, you may be able to increase your quality. If your quality is just barely good enough to maintain a signal on a sunny day it may suffer with bad weather... making it a great signal may help... hard to do where you are sounds like.
Things to think about in no particular order:
1) height of your house in relation to surroundings (trees/mountains, tall buildings, etc)
2) Distance from your antenna to the TV.
3) cable. use RG6 quad shielded.
4) nearby metal stuff... especially the other antenna... are they directly below each other? depending on the wavelength of the largest wavelength channel you want you need to be future apart than that from other metal things... mine is 3 ft vertically. More than that horizontally.
5) You may be getting too much interference... static in the old days. Using a preamp does not fix interference... just makes it amplified like the signal, which could make matters actually worse.
6) Asphalt and large structures can bounce signals too. When choosing to point to the side of my large tree, I pointed to the left of it because to the right I lined up perpendicular to the road in front of my house... so I was receiving signal in the air straight from the tower then milliseconds later receiving signal from bounce off my road -AKA: interference.
7) i don't think wind affects signals too much. I've had strong winds with good reception. Bad weather on the other hand can. cloud coverage without bad weather can actually improve far away signals... Mine has also done fine with snow on it.
You may consider a directional antenna. They improve signal reception by not trying to hard... I have a directional antenna that has a 45 degree pickup range... so it's not too directional. Also, you'll pick up channels from the back too (ex: my antenna points at about 2Oclock to most of my channells and picks up PBS from about 7 Oclock.
9) you might consider not using a pre-amp, but using an amplified splitter or a amp later half way if your cable distance is long.
10) Higher is almost always better. Mine is on roof on 2nd floor about 10 ft above roofline.
I have this feeling there is more... but... can't remember
Even still... bad weather rolls though and you get pixelation...
the new system the gov settled on dhtv requires enough strength for picture and sound at the same time so you'll need a 65-70% strong signal to keep a clean picture.... not sure why they didn't let though just the sound... at least in the old days if you have a bad signal you could get a fuzzy picture and sound... No It's not just the way it is.... It was a standards decision regarding software. Europe can lose picture and still have sound.... oh well.. I'll stop rambling...
Hope that helps! good luck.