During the summer months, the Lake Tahoe area is typically blessed with sunny warm weather. Perfect for boating. But, as any Tahoe resident or frequent visitor knows, thunderstorms are a common phenomenon here.

Thunderstorms and boating do not mix well. One minute you are happily relaxing on your boat, cruising Tahoe’s famous calm blue waters. Ten minutes later panic takes over, as driving rain, high winds, frequent cloud-to-water lighting, and enormous swells churn the lake into a Tahoe’s version of “Deadliest Catch.”

Thunderstorms can build quickly in the Sierra. Warm moist air rises high into the atmosphere, where it cools and condenses into towering cumulus clouds. As these clouds build and move over the terrain, they develop electric charges. Typically the tops of clouds will accumulate positive charges, while cloud bottoms develop negative charges.

Air is not a good conductor of electricity. Instead of constantly grounding themselves, thunderheads will continue accumulating electrical potential until the potential is enough to overcome the resistance of the air. Lightning is the attempt to even out the electrical charges within clouds, between clouds, and from clouds to the ground — or water.

During the average thunderstorm day, 70 percent of lighting will occur between noon and 6 p.m. On the flat surface of the water, lighting will seek out the highest grounding object in its vicinity — likely to be a boat. When lighting strikes a boat, it will seek the path of least resistance to discharge into the water, starting with the highest part of the boat. That could be a radio antenna, a graphite fishing pole, or a person. Unfortunately, people are fairly decent conductors of electricity.

It is reasonable to assume that keeping an eye out for approaching thunderstorms would confer some measure of immunity upon attentive boaters. However, it is unlikely that a boater will be able to hear thunder from a storm that is more than five miles away.

Five miles might seem like a long way off; however, given typical cloud movement, a thunderhead that is five miles away can be overhead in 10 or 12 minutes. And the storm will have undoubtedly kicked up waves in all directions well in advance of its approach. Outrunning an electrical storm aboard a small boat in rough water is an arduous, if not improbable task.

There are some easy precautions one can take to minimize the risks of being caught in a thunderstorm on the lake. The most obvious is to plan ahead for the weather. Use the Wx channels on the VFH radio for weather updates. Even better, have a web-enabled cell phone on board to check the latest satellite images. A good set of eyes on the horizon will alert boaters to building thunderheads. If thunderstorms are building, it is time to head for shore.

In the event you actually do get caught offshore in a violent storm, there are a few things to do. Most importantly, put on lifejackets. Stop fishing, skiing, or towing inner-tubes, and head for shore. Lower the marine radio antenna. Switch off all unnecessary electronics. Stay in the center of the boat, and stay low in the boat; preferably below-decks. Keep arms and legs inside the boat.

If you are already ashore in Emerald Bay and thunderstorms suddenly approach, it is probably best to just stay where you are and wait it out. The storms will likely dissipate within a couple hours. Then you can resume enjoying Tahoe’s famous calm blue waters.