A couple of thoughts (but I am no expert at sailing through squalls):
If you expect the storm to be short in duration; it might be better to sail into it instead of running away from it. Sailing upwind through the storm will reduce your time in the storm and hopefully the seas wont build as much as they would if you were traveling with it and toward shallow water (if you are running back to the coast).
If you can't sail into it, and you don't want to sail away from the squall; consider a heave-to and waiting for it to pass. A 150% genoa would be a tall order to do this; but if you had a correctly sized sail for heavy wind (100% or smaller); sitting hove-to is incredibly comforting when it would be seemingly horrible conditions. You should practice this in moderate conditions; and try it on days when the wind is up but the seas are relatively flat. Your drift should be 1kt or less; but you still need to be well off of a lee shore so you don't drift into breaking waves.
Single line reefing systems are notoriously bad for sticking and not providing adequate outhaul tension. Practice reefing with the sail and know what the problems are before you need to reef in heavy conditions. Single line systems can require one person pulling the line on the boom and the second person tailing/grinding the winch to overcome the friction in the system. If you don't get the sail properly reefed you could end up tearing the sail in gusting winds.