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GRAND RAPIDS, Mich. (WOOD) — The distant sound of rolling rumbles of thunder is certainly one sign of spring, therefore marking the beginning of severe season.

As a result, Michigan Gov. Gretchen Whitmer has declared March 24 through March 30 Severe Weather Awareness Week

After several months of winter, it’s a good refresher of how to prepare for the potential of severe weather.

The first intrusion of warm temperatures on March 14 brought Michigan’s first episode of severe weather.
Four tornadoes were reported just west of Flint, including one rated EF-2 with winds in excess of 110 mph. Fortuantely, there were no serious injuries.

The event is a good reminder of what this week is about, helping keep Michigan residents prepared and safe during severe weather. Meteorologists identify severe thunderstorms by size of hail, strength of wind and, of course, whether or not they produce a tornado. It’s important to note all thunderstorms can be dangerous, even if they don’t technically reach the criteria to be termed a severe thunderstorm. This is because they all emit lightning.

Between 1990 and 2003, 13 fatalities occurred in Michigan with many more injuries. Below, a map from Shayna Fever identifying where lightning fatalities have occurred across the United States. 
The general rule of thumb is if you can hear thunder, you are close enough to get struck by lightning. During rare occasions lightning can strike from the top of a thunderstorm and extend several miles away from the parent storm. We call these “bolts from the blue,” or from the blue sky.

Here are a few tips to help you stay safe during a thunderstorm:
It’s good to adhere to the 30/30 rule. There is a simple way to estimate how far away a lightning bolt has struck by counting the number of seconds between when the lighting strike and the time you first hear thunder. Then you divide that number by five.

For example, if you see lightning stike in the distance start counting. If you count to 15 by the time you hear the thunder, then that lightning bolt struck three miles away.

So, anytime it takes you to count to 30 seconds or less, you should seek shelter. Once the storm passes, wait 30 minutes after the last sound of thunder before venturing outside.

When thunderstorms reach severe criteria, such as hail an inch or greater, and 58 mph wind gust or higher — here are a few additional safety tips:
Michigan averages 15 tornadoes annually. Tortuantely for us, most are weak EF-0 and EF-1 tornadoes with winds less than 111 mph. These weaker tornadoes are also more difficult to identify on radar and therefore warn for.

The continual advancement of radar technology has helped increase the average lead time for a tornado warning to 10 to15 minutes. If a tornado warning has been issued for your location, it means it’s time to take action.

The strongest winds of a tornado are typically above the surface so you always want to seek shelter as low as you can find it.But this is where you come into play. When there is the potential of severe weather, you must be in a heightened sense of awareness that it could occur.

This means having a plan to receive any warnings from wherever you are located whether you are at home or if you are out and about.

There are various apps, such as the Storm Team 8 weather app, can warn you if and when there is severe weather in your area.

When severe weather is imminent, you need to know what to do. This is a good week to have the discussion with the family of what to do if there is severe weather, where in your house is the best location to go and what items are important to have when seekeing shelter — such as a mobile phone, battery powered radio and a flashlight or two with fresh batteries. It’s also a good idea to have food and water available.

Fortunately, the severe weather trend has been a good one in Michigan. Eight of the past 10 years we have recorded below average severe weather reports. The only years recording above average reports this past decade were 2008 and 2011. 
Nationally, the trend has been favorable as well. Despite a higher population density and more weather spotters, the trend for strong to violent tornadoes has gone done in recent decades. The first year without an EF-4 of EF-5 tornado reported in the U.S. was 2018. 
Despite the favorable statewide and national trend, it only takes one event to catestrophically change lives. Always be prepared,  because it’s not a matter of if severe weather will strike but when.