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Thunderstorms rumbling on North Idaho horizon

| May 10, 2020 1:00 AM

We’re in the middle of thunderstorm season across the U.S., including North Idaho. So far, we’ve only seen one thunderstorm, which occurred on April 27. Last month was drier than normal as only 0.99 inches of rain fell at Cliff’s station in northwestern Coeur d’Alene. The normal precipitation for April is 1.77 inches.

Rainfall this month is expected to be near or a little higher than the normal of 2.37 inches. However, the number of thunderstorms in the region should be near to a little below normal this year. We will probably have about six thunderstorms with rain and perhaps some hail. There should be another six that are not expected to be quite as strong.

Here in North Idaho, the average number of days with thunderstorms, which include thunder, lightning and rain, across the lower elevations is 14 (1 in April, 2 in May, 5 in June, 2 in July, 2 in August, 1 in September and October). When you include days with thunder and little or no rain, the average number of days goes up to 25. The normal number of extreme severe weather days in the Inland Northwest for an entire year is slightly less than one.

Worldwide, it’s estimated that between 14 million and 16 million thunderstorms will form each year. It’s almost hard to believe, but there are close to 2,000 thunderstorms in progress during every minute of the day.

An article from Reader’s Digest about thunderstorms says that lightning will strike more than eight million times per day across the world, which is about 93 times per second. In the U.S., there are approximately 100,000 thunderstorms that form each year, and, according to NOAA, about 10% of them will often reach severe levels.

At this time of year, it’s a good idea to keep tabs on the local weather, especially if there are thunderstorms forming in the area. During these conditions, the National Weather Service can issue a “severe thunderstorm watch” or a “severe thunderstorm warning.”

A watch means conditions are favorable for the formation of severe thunderstorm activity. However, a warning means that severe weather is in progress when storm spotters or Doppler radar show storms producing large hail, high winds and heavy rainfall.

With thunderstorms come lightning, which is still one of the most mysterious meteorological phenomena. A single bolt of lightning can be as high as 40,000 to 50,000 degrees Fahrenheit. That’s hotter than the surface of the sun.

Powerful thunderstorms have strong updrafts of warm air and can exceed 100 mph. When the rising air becomes cooler than the air surrounding it, the rising air will spread out, creating an anvil-type cloud. On the other side of the cloud are the downdrafts. This is the area of rain and hail. If there is rotation in the cloud, tornadoes can form, especially in areas east of the Rockies.

It’s not a good idea to venture out during a thunderstorm. The odds of being struck by lightning in any one year is 1 in 700,000. However, the odds of being struck in your lifetime go up to 1 in 3,000.

If one happens to be outdoors during severe weather, and the hair starts standing straight up, that means conditions are setting up fast to be hit by lightning. The best thing to do is to hit the ground and even roll to break the bond between the positive and negative charge.

During a thunderstorm, or shortly after, it’s never a good idea to drive through a flooded area of the road. It takes only 6 inches of standing water to cause a car engine to stall. A foot of water can literally sweep a car off the road.

If you’re indoors during a thunderstorm, it’s best to avoid using land-line phones, computers, cell phones and other electronics. When I lived in Vermont many years ago, I got a few shocks in my ear when I was on the phone and lightning was close by. Electrical wires are a good conductor of lightning and I’ve also had many electronic devices destroyed by severe thunderstorms.

It’s also not a good idea to shower, wash your hands or do anything that involves using water. Many of the pipes that transport water are metal and present a hazard. And, water is also a conductor of electricity, so avoid being on the water on days with expected strong thunderstorm activity.

In terms of our local weather, Cliff and I expect to see an increase of rain and thunderstorm activity between now and into early June. Then, conditions are forecast to turn drier and much warmer later next month. The summer season should be similar to last year with below-normal moisture, but not extremely dry. Temperatures are also expected to be hotter in 2020 with a few days around the 100-degree mark.

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Contact Randy Mann at randy@longrangeweather.com