What is a recommended method for determining distance from an approaching thunderstorm?

The recommended method for determining the distance from an approaching thunderstorm is to count the seconds between the flash of lightning and the sound of thunder. This technique is based on the difference in the speed of light and the speed of sound. Light travels much faster than sound; specifically, light reaches the observer almost instantaneously, while sound travels at roughly 1,125 feet per second in the air.

By counting the seconds between seeing the lightning and hearing the thunder, a person can estimate how far away the storm is. For every five seconds counted, the storm is approximately one mile away. This method allows boaters to assess the risk of the storm and take appropriate actions, such as seeking shelter or returning to shore.

Other methods, such as counting the number of waves, measuring with a compass, or using a GPS device, are not effective for determining the distance of a thunderstorm. Counting waves doesn’t provide any relevant information about the weather, measuring with a compass does not relate to storm distance, and while GPS can give geographic locations, it does not measure or indicate the presence or distance of storms. Hence, counting the seconds is the practical and recommended way to gauge the storm's approach.