Buehner: With March around the corner, thunderstorm season is fast approaching

In the wake of Sunday’s wet windy weather system, much cooler and unsettled weather with showers and low snow levels has arrived and will extend into Tuesday. With the threat of thunderstorms back in the forecast, this weather pattern is right on schedule and helps kick off the primary thunderstorm season of the year.

Western Washington’s primary thunderstorm season usually begins right around March 1. Thunderstorms can occur any time of the year, but this region actually has two peaks – spring and fall, with spring the primary season.

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Thanks to longer days, temperatures near the surface tend to be warmer in the spring than during winter. Yet, cooler air aloft continues to move onshore from the Gulf of Alaska, creating an unstable air mass or as an analogy, rising bubbles of air – much like boiling water on a hot stove – that can produce showers and thunderstorms.

However, Western Washington averages only about 10 thunderstorms per year. This average is in sharp contrast with central Florida which gets over 100 thunderstorms annually.

From the Rockies eastward, people are rather lightning proficient, heading indoors when a thunderstorm approaches. Since Western Washington does not get numerous thunderstorms, many people are caught unaware and outdoors when lightning strikes.

Western Washington thunderstorms are usually short-lived, less than 30 minutes. If a cold rain or hail shower approaches, it could produce lightning. Head indoors or get into a vehicle. Avoid tall targets like trees. Lightning likes to hit elevated objects and that is where many lightning injuries and fatalities occur.

Fortunately, Washington has not had a lightning fatality since 1996. Let’s keep it that way. Remember – when thunder roars, go indoors.

This cool unsettled weather pattern will produce showers through Tuesday with snow levels around 500 feet primarily during morning hours. The Cascade foothills and higher elevations could have accumulating snowfall in healthy showers, primarily on grassy surfaces and rooftops. Highs through Tuesday will end up in the range of 40-45 degrees, about 10 degrees colder than average for late February. Lows are expected to be in the 30s.

In the mountains, this pattern with westerly flow aloft rising up into the terrain, should pile up the snow. Through Tuesday, 1 to 2.5 feet of much-needed snow is expected in the Cascades. For motorists crossing the Cascade passes though, travel conditions will be challenging with snow on the roads.

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The next wet Pacific weather system is expected to sweep through Western Washington Wednesday. Mountain snow levels will temporarily pop up to nearly 3,500 feet with rain in the lowlands and highs from 45 to 50 degrees.

Following this system, another surge of cool unsettled air will produce more showers Thursday and Friday with snow levels dropping back down close to 500 feet. In the mountains, another one to three of fresh snow is anticipated, creating difficult driving conditions once again. As the work week wraps up, highs will remain well below average in the 40s.

With Friday the first day of March, it looks like the month will come in as a lion.

Ted Buehner is the KIRO Newsradio meteorologist. You can read more of Ted’s stories here and follow him on X, formerly known as Twitter.