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Thunderstorms looming, booming on horizon

| April 4, 2022 1:08 AM

April has arrived and moisture has started to increase across the Inland Northwest.

Until recently, it has been pretty dry in our region with no moisture seen at Cliff’s station during the last eights days of March.

Over the next several weeks, there’s still a slight chance we could see a few flakes of snow, but any amount in the lower elevations should be light. Based on the current patterns, the Inland Northwest will likely have near to above normal moisture this month and into May before turning drier than average in the late spring and summer.

Despite the recent dryness in March, moisture totals in the region are still above-normal levels for 2022. Since the beginning of the year, Coeur d’Alene has received around 9 inches of rain and melted snow. We have also picked up 20.3 inches of snow since the start of the year.

However, most of that fell within the first seven days of January. We’re still amazed that after a 50-inch start to the snowfall season through early January, only 6.5 inches have fallen since Jan. 8, the most snowless stretch at this time of year in recorded history.

With additional storms expected across the region, Cliff and I see thunderstorm activity increasing across North Idaho this month and continuing into late May or early June.

We’re already above-normal for the thunderstorm season as two of them were reported last month. Overall, the number of thunderstorms in the region should be near to a little above-normal this year as we’ll probably have an additional six thunderstorms with rain and perhaps some hail.

There should be another eight that are not expected to be quite as strong, for a total of 16 for this year.

Here in North Idaho, the average number of days with thunderstorms, which include thunder, lightning and rain, across the lower elevations is 14 (one in April, two in May, five in June, two in July, two in August, one in September and October). When you include days with thunder with 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.

Many of us plan our vacations in the late spring and summer months. Some of the journeys will involve air travel across the country. During this time, much of the country, especially east of the Rockies, will see the development of thunderstorms during the afternoon and evening hours which can make plane travel a bit tricky. We’re already seeing major outbreaks of severe weather across the southern portions of the country.

Strong thunderstorms have strong updrafts of warm air and can exceed 100 miles per hour. 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.

Thunderstorms that develop near airports often lead to long delays, creating lots of frustration for passengers. But safety is a priority with the airlines. In the air, pilots will always try to fly at an altitude where turbulence is minimal. They will do their best to fly around thunderstorms to avoid strong turbulence.

I mentioned this story several years ago, but I remember an occasion in the early 1990s, when I was on a flight with Cliff and we were heading into a thunderstorm. He was sitting in the window seat and I was in the middle. He looked out and saw the large billowing clouds and said, “I think we’ve had it.” My response was quick and fairly loud as I replied, “We’ve had it?!” I think half the plane heard me. Shortly after, we went through the thunderstorm and the plane was shaking and dipping. It was a wild ride and I was very glad to get on the ground. The pilot got a nice applause when we landed. Cliff and I still have a good laugh over that incident, but it didn’t seem so funny at the time.

There are cases when pilots have to fly through a weather system. Most aircraft will cruise at an altitude around 35,000 feet. Strong thunderstorms can form as high as 60,000 feet, so the cloud tops can be significantly higher than the altitude of the plane. I will say, however, most pilots do a great job at navigating around severe weather. If you don’t like the potential for turbulence, the best time to fly is early in the morning as the heat from the day can trigger thunderstorm activity during the afternoon and evening hours.

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Contact Randy Mann at randy@longrangeweather.com

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