Weather Eye: Clash of air masses could produce thunderstorms




Today and Wednesday, we could see enough unusual activity to get weather enthusiasts excited. A chance of thunderstorms will exist mainly over and east of the Cascades but there’s also a risk here in the western part of the state.

As of Monday evening, we had a cold low-pressure system off the coast of British Columbia and a upper level low off northern California and southern Oregon. The latter was moving northward, while the B.C. low was edging slowly southward.

They will combine and bring good rains in some locations. We possibly could get a half inch of rain here in Clark County. A tricky forecast to say the least. We could see rain most of the day on Wednesday or just off and on. Regardless, we remain underneath this clash of the air masses.

That’s a mixed blessing for firefighters in Eastern Washington. There could be cool temperatures and showers, but also lightning and gusty winds, maybe hail.

Thursday will be a transition day back to more summer-like weather, and we will be back into the 80s and 90s Friday through Sunday. So, a brief interlude during an otherwise perfect summer.

At 5 p.m. Monday, temperatures were in the 80s east of the mountains and winds were on the quiet side. All good news for those battling wildfires. My high didn’t quite make it to 80 degrees Monday, falling one degree short. Vancouver officially recorded 76 degrees.

One note about the incoming weather system: snow may fall down to the 7,000-foot level in the Cascades ,and we may see a chilly summer morning on Thursday if skies clear out overnight.

Enjoy the brief interruption to our string of lazy summer days and we will chat on Thursday.

Remember, if thunder roars, go indoors!

Patrick Timm is a local weather specialist. His column appears Tuesdays, Thursdays and Sundays. Reach him at