Originally Posted by sailaway21
Long leads on head, stern, and spring lines will allow for storm-surging.
Agreed. Slack them off a bit if the space in your slip will allow it. Double up your lines. Use chafe gear at the chocks, add fore and aft spring lines, deploy ALL your fenders and don't neglect the side not facing the dock, as this protects you from the other guy if he comes loose, and protects other guys from you if your dock fails. If you expect serious, sustained heavy weather, strip off your furling sail and lash down your sail cover to your boom.
Consider hanging a fender board between your midship fenders and the dock. This can be a wooden plank, plastic board or PVC piping:
Making Your Own Fender Boards in 2 Easy Steps
If the water is surging, the board will keep the fenders down, along with distributing the load. If you can get old tires as fenders, so much the better, as they won't ride up as easily.
Lastly, check that your bilges are clean and free of debris that could foul your pumps. Leave the power ON as you may need the batteries fully charged to run the pumps. Close the thru-hulls (except in the cockpit, which need to be checked for debris) and close all hatches and portlights. You'd think this would be obvious, but a boat at our club with a scoop transom habitually had a cockpit portlight from the quarterberth open for ventilation, and took on water from getting "pooped at dock".
Hope this helps. I have been smirked at on occasion for the "robustness" of my docklines and the preparations I take, but I never worry about the boat on windy/stormy days.