PORTLAND, Ore. (KOIN) — Get ready for a sneaky warm day, as temperatures start to increase this afternoon. The weekend started below average, with highs only reaching the lower 80s on Saturday. With fewer clouds and still plenty of heat around the Pacific Northwest (PNW), we should anticipate a warmer finish to the weekend. We will start the day in the 60s, most likely in the mid-60s for Portland and surrounding communities. Even with relatively cooler temperatures on Saturday afternoon, we aren’t expected to cool down much early Sunday morning, leading to a mild start to the day.
Weather models have our daytime high in the lower 90s to mid-90s today. That is our potential high temperature for Portland, but I believe with some morning clouds and a layer of smoke, we may stay near 90 degrees on the mark. The heat continues for the Lower Columbia Basin, with temperatures cracking the mid to upper 90s again. Hermiston, Umatilla and Boardman are going to be the cities that have the warmest temperatures today. That pocket of heat has been pushing those communities just about all summer. There have been some exceptions, but there haven’t been many. Temperatures in the mid to upper 60s for the Oregon Coast, with even a 70-degree forecast for Tillamook. Passing clouds, but sunshine is possible too.
I mentioned that there is still plenty of heat to tap into around here. I want to show you a sounding from Saturday morning. This is when we send a weather balloon up into the atmosphere and it sends back data, which we use for forecasting and for the weather story. You don’t need to know much, other than if you trace that red line from the bottom to the top, you will notice a large spike, that projects out like a nose. That is warmer air that is sitting around 4,000 to 5,000 feet. That heat isn’t going very far, which means we still have the ability to mix that down to the surface. That is exactly the case the next few days as high pressure stays locked in. If you cycle to the second graphic above, a massing ridge of high pressure extends all that way up into Canada. That will tilt back in our direction the next few days, keeping temps up.
We may also have another round of isolated thunderstorms (t-storms) for Oregon and Washington today. Morning showers and t-storms to the north, possibly through areas of the Blue and Wallowa mountain ranges. A moment of reprieve in the late morning and early afternoon before more isolated t-storms develop in the afternoon. Cycle to the next graphic below and you can see a few of the cells developing through the region. You may notice that it is mostly clear from Linn county north up through the valley. A few clouds may push north in the afternoon and evening, but don’t expect much outside of a smoke haze. Not as active on Sunday as what we had going on Saturday.
You may notice a large t-storm trying to develop north of Medford tomorrow afternoon and into the evening. Weather models are pushing some energy in that section of the Cascades and foothills. We will have to monitor the situation, but we do have potential energy showing up on the weather models tomorrow afternoon. We can’t rule out the chance for more lightning and gusty conditions with these cells that do develop. This may pass near areas of the Jack Fire if the weather models come to fruition.
We are losing a few things today, which may limit our overall thunderstorm development. We are losing the depth of moisture from Saturday, and also the enhancement from the wind aloft. This is going to lead to more isolated t-storms than scattered from earlier in the weekend. It also means we are likely going to have fewer downpours with this set of storms. There is something we will not escape, and that is the ongoing heat. Stay safe and stay cool.