It is a classic mid-Missouri summer scenario: you are spending a hot afternoon boating on the Lake of the Ozarks or lounging by the community pool when the sky turns dark and a distant rumble echoes across the water.

Your first instinct might be to squeeze in just a few more minutes of swimming before the rain starts. However, atmospheric physics proves that the moments before a storm hits are actually the most dangerous, especially if you are anywhere near the water.

To understand why water and lightning are a dangerous combination, you have to look at the unique way electricity behaves on a liquid surface.

A common scientific misconception is that pure water is an excellent conductor of electricity. In a controlled laboratory setting, pure H2O is actually an insulator. However, the water we interact with in the real world, whether it is the treated water in a swimming pool or the natural water in our regional lakes and rivers, is packed with dissolved minerals, salts, chlorine, and organic impurities.

These impurities completely change the game, turning the water into an efficient conductor.

When a lightning bolt strikes an open body of water, the electrical current does not simply plunge straight down to the bottom. Instead, the electricity shoots outward horizontally across the surface, easily traveling for dozens of yards.

If you are swimming when a nearby strike occurs, your body poses a major hazard. Because human tissue contains high amounts of water and dissolved electrolytes, you are actually more conductive than the surrounding lake or pool water.

In the world of physics, electricity always seeks the path of least resistance. If you are in that horizontal dissipation zone, that path is you. Even a near-miss that does not strike you directly can discharge enough electrical current to stun or temporarily paralyze your muscles, leading to immediate drowning.

The danger is just as great for boaters. On a flat, wide-open body of water, a boat is typically the highest object around. Because lightning seeks the highest ground to discharge its energy, your vessel essentially becomes a floating lightning rod.

When it comes to lightning safety, there is no room for compromise. If you can hear thunder, you are close enough to the storm to be struck by lightning.

A couple of important things to remember are that, first, open shelters do not count. A pool pavilion, a canvas boat canopy, or an open-sided picnic shelter will not protect you from a side flash or a direct strike.

Second, seek real shelter. The moment you hear thunder, get completely off the water and head into a substantial, fully enclosed building with plumbing and wiring, or a hard-topped metal vehicle.

Finally, start a 30-minute clock. Do not head back to the dock or the deep end just because the rain stops. Wait a full 30 minutes after the very last rumble of thunder before returning to outdoor activities.

As we enter the weekend, it will be important to keep an eye on the sky for any outdoor plans. Chances of showers and storms are expected at least for Friday, gradually decreasing throughout the weekend into next week. Getting the ABC 17 Stormtrack Weather App is one of the best ways that you can stay informed about storms in your area that could pose a threat to any activities you may have planned.