Also, if this exam is so important...what's equally (or more!) important going on two days prior that you cannot begin your travel earlier? (Not that you have to answer, I'm just raising the question. :) There is still plenty of time to rearrange your schedule.)

Otherwise, agonizing over the weather right now is pointless...a storm could hit CLE on that day and all flights on all carriers could be cancelled.

The SAT. ;)

Ah, the wonderful fun of being a high school senior applying to competitive colleges... :(

Sounds like you had your mind already made up prior to posting here. Nobody can predict weather - even seemingly weather people on the news for the next day. I thought that the SATs can be arranged to be taken elsewhere than your hometown?

If they can, (where is boeingair - SAT extraordinare person! who could answer that for sure? ;)), then my recommendation would be to fly to the appropriate city (since you're keen on only flying)e.g., DCA - take the SAT then your other test. Fly out a few days early so that if there is weather you're not delayed; if there isn't weather then you have time to study.