May 19, 2021

Forecast: May 19th, 2021

By Matthew Charchenko

I don’t know about all of you, but I was missing the occurrence of isolated springtime thunderstorms that are typically associated with cold air aloft and daytime heating behind cold fronts. Our warm and dry springtime weather has meant that most of those storm systems have steered clear of the area. However, we finally got some of that thunder action yesterday with daytime heating causing just enough instability to fire off some storms out on the eastside and over Puget Sound.

Today will essentially be a rinse and repeat of yesterday by combining that cold air aloft with scattered showers and sunbreaks. One of the parameters we look at when forecasting thunderstorm risks is CAPE, which stands for convective available potential energy. This parameter shows us exactly what it sounds like, the amount of convective energy that is available in the atmosphere. As you can see, we do have some CAPE scattered across Western Washington, so if there is enough daytime heating then we could see a few more rumbles of thunder.

This cold trough of air that is sitting over the northwest will start to work its way out of the region bringing warmer weather by this weekend.

Highs today will be running about 10 degrees below average with most locations only making it into the mid to upper 50s.

Another weak disturbance will make its way into the area tomorrow morning, bringing another round of showery weather on Thursday. If the cool and showery weather is making it feel more like March instead of May, then you are in luck as sunshine returns on Friday. Saturday is looking like a beautiful one with high temperatures making it to either side of the 70 degree mark.

Reach forecaster Matthew Charchenko at theuwdawgcast@uw.edu. Twitter: @mcharchenko

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