Thunderstorms are more than a nuisance. The high winds and pouring rain can cause damage to your home, knock out power for hours, and leave you with thousands of dollars in repair bills. Thankfully, you can prevent a lot of these hassles and problems by preparing your home for the summer thunderstorm season. Here's a look at three things you should do to prepare.

Make sure your AC unit is properly bolted down and protected.

Your AC unit should be on a concrete slab, and it should be held onto that concrete slab with metal straps. If your AC unit is still freestanding on the slab, you'll want to contact your air-conditioning service and arrange for them to come bolt it down before the high winds come. You wouldn't want your unit getting blown to the side or tipped over if something else bangs into it. Also, make sure you have a cover for your AC unit. Before a big storm rolls in, you'll want to turn off your air conditioning and cover the unit to prevent sticks and other debris from blowing into it and to prevent hail from damaging it. A cover made specifically for the AC model you have is best, since it will fit it closely and provide padding in the right places.

Test-run your generator.

If the power goes out for more than a minute, having a generator will come in handy, as it will keep your fridge running and prevent food from spoiling. It can also ensure you still have hot water and the use of other basic appliances. Test-run your generator now so you can ensure it's functioning properly. Also, make sure you have plenty of fuel (gas or propane, depending on your generator) set aside so you're not left powerless in a storm.

Secure your gutters and downspouts.

Use your hand to jiggle each gutter and downspout. If any seem loose, use a screwdriver to tighten the metal strap that fastens them to your home. You don't want them blowing off in a storm, as they may collide with another structure and cause damage. Also, make sure there's no debris in the gutters. Scoop any debris out with a trowel and rinse the small stuff out with a hose. This ensures your gutters drain properly when the rain starts pouring down so you don't end up with water damage to your roof.