While Don does outstanding work, one of the things that he has going for him is that he lives in Florida. Florida tends to have some very steady viewing, due to large, broad high pressure areas that settle over the Southeastern United States. Being near that intersection means many a time when there is little going on aloft, and thus very little turbulent air to deal with. In part 1 of this 2 part series I suggested what kinds of objects you should view given different kinds of weather scenarios.
Atmospheric clarity is pretty easy to forecast, so let's start with the simple stuff.
The air is often unsteady behind these fronts, especially in the winter. On the other side of the coin, when cold fronts first approach, the loss of atmospheric stability can be a particular problem, especially in the summer, as thunderstorms may brew. In addition to the approaching thunder, clouds and rain often precede cold fronts, so your best bet is to wait until it passes by. Warm fronts are usually associated with clouds as they move in, but often it clears behind them. Especially in the Eastern U.S. though, this will be followed by hazy conditions, not condusive for deep sky viewing, but often satsifactory for planets, especially if the winds go light.