PORTLAND, Ore. (KOIN) – Grab your flannels and gear up for some cooler fall weather this week. After a weekend that brought in relatively mild temperatures (a few degrees above average), we are not looking to turn to some cooler air.
The week should still start off just about average, with highs in the lower 60s. Persistent northwest flow aloft will keep us around average and it will also keep the threat for on and off rain showers because of a handful of quick-moving disturbances. Temperatures are uniform across the state on Monday for the exception of Medford, where the temperatures are still running warmer than the rest of the state.
Check out what happens to the temperatures as the week moves along. Expecting cooler air to move in from the north and this will take our daytime highs down to the mid 50s by Friday. For now, the weekend is looking to be pretty chilly. Weather models are leaning towards a rush of colder air for the Pacific Northwest (PNW) by Saturday. This is subject to change, but we may have some winter air moving our direction.
Below are two photos from our weather pattern graphic that will help paint an idea of what is going to occur over the next 5 days. We stay in touch with that northwest flow through Tuesday, before some colder air starts to infiltrate our region from the northeast. We bottom out around Saturday with temperatures probably a good 10 to 15 degrees below average. You can see in the right image that the cold air moves in from Canada and extends west to the Columbia Plateau and subsequently the river basin.
As far as rain goes? I wouldn’t expect much this week until we get to about Friday. Those weak disturbances may bring an isolated shower or two, but we aren’t expecting anything consistent until late week. However, clouds will be in and out from Monday through Friday. The sunniest day of the week will likely come on Thursday (after some morning fog). If you don’t have a heavier jacket ready, it may be time to start hunting for that too.