PORTLAND, Ore. (KOIN) – Unsettled weather comes Sunday afternoon after a moment of unease on Saturday with a few passing showers. Sunday’s system will be more organized and this allows for a higher chance of measurable rain in the Willamette Valley. Let’s go ahead and talk about timing real quick. Clouds move in overnight and we will call it mostly cloudy Sunday morning. A passing warm front with a southwesterly flow should usher in some moisture. This is all prior to the cold front which moves in during the afternoon. It is the cold front that will spark the rain and even a few potential thunderstorms. I will note that there may be some light showers for the Oregon coast by the morning. Heavy showers take over for the coast by mid-day, with that risk for thunder. Light showers may start forming around Portland too. Between 2 p.m. and 4 p.m., showers and wind will likely increase around Portland. It’s that late afternoon window that looks to bring in the heavier showers around here. That cold front passes quickly, eventually bringing in scattered showers and sun breaks by the early evening.
Weather models are having a hard time with this system, but I anticipate the totals to be location-dependent. Very similar to the rain event we had in late May where some locations in downtown gathered plenty of rain and the airport only had a minor amount. I would count on totals to be around .10-.25 inches in the valley. The southern valley may actually see very little rain as the bulk of the forcing will stay to the north. Higher totals for the northern Oregon coast and southwest Washington. Not anticipating the rain to make it beyond the Cascades, however, The Dalles may see some light rain.
For you folks east of the Cascades, it’s going to be one of those windy days. Clouds and rain west of the Cascades and more sunshine and wind to the east. The wind gusts will pick up around Portland too as that cold front comes marching through the valley. The wind will pick up to the 10 to 15 mph range early in the day but then it accelerates to the 25 to 30 mph range by the afternoon and late evening. This is also the time period where we may have some breezy conditions from Wasco down south to Deschutes county. Wind gusting to the 30 or even 40 mph range according to weather models. Brace for some breezy moments in the afternoon.
As far as temperatures go, they will be cool through the morning and early afternoon under clouds. Once that cold front moves through and the sun breaks start to show up, we may have temperatures bump to the mid 60s. If you want to get through some outdoor work without rain, you should start early in the valley. Temperatures will be below average across the board, that goes for you folks in central Oregon too. It will feel more like an early spring day around here.