According to weather forecasters, there was a 5% chance of tornadoes and a 15% chance of large hail as a series of storms moved through Clark County and the rest of Western Washington last Wednesday, March 26.
Ultimately, neither severe weather scenario came to pass.
The Pacific Northwest garnished the attention of midwest storm reporters, especially from the National Weather Service’s Severe Storm Prediction Center based in Oklahoma, for a possible threat of super cells.
Instead, there were just a few flashes and bolts of lightning in Clark County and no strong wind until Thursday, March 27.
There was certainly no giant hail or twisters.
The Portland office for the National Weather Service stated that forecasting severe thunderstorms is a challenge, and that in the Pacific Northwest, they become even more of a challenge to forecast.
“For this event, there was Storm Prediction Center guidance and agreeance with local weather forecast offices for a Severe Thunderstorm Watch,” they stated. “This was due to the scientifically sound potential of a severe thunderstorm’s ingredients being present.”
The National Weather Service Portland office also detailed the “ingredients” for a severe thunderstorm and what actually occurred on March 26.
The first ingredient they listed is equal and adequate moisture. The Portland office stated that moisture was heavier at the surface and above 10,000 feet, but not at the 2,000- to 10,000-foot layer like weather models suggested.
The next ingredient listed is lift, the trigger for a thunderstorm, they stated. The storm front moving in and the strong wind in the upper-level of the atmosphere provided enough lift in the area, the Portland office stated.
The majority of storms that did develop began in Clark County and continued north through the Interstate 5 corridor toward Seattle. There was enough wind shear for a thunderstorm’s structure, but not enough other ingredients came to fruition to create the severe storms that were initially predicted.
Another ingredient, instability, didn’t occur as the temperature ended up 2 to 5 degrees cooler than what was needed. The temperature drop resulted from a push of ocean air and cloud cover coming in earlier than expected.
The National Weather Service Seattle office added that the event serves as a reminder that severe thunderstorms can happen in Western Washington.
