PORTLAND, Ore. (KOIN) – If you have plans to visit family or to take a small trip for Thanksgiving, and it includes getting in the car, we have you covered.
Thanksgiving travel will come with some hiccups, but mainly before Thursday and it will mostly be situated in the terrain of the Cascades.
Continued northwest flow will keep the snow coming down for the Cascades Tuesday afternoon. We have a tile of images that cover the nearby passes and major routes. It will be snowy and icy up near Government Camp and Santiam Pass. You can expect a similar scene coming out of the Willamette Pass. This will be the hiccup to the holiday travel if you plan on leaving today. Visibility and travel should be easier on Wednesday or Thursday morning. This should allow for a day or two for the roads to improve.
For those of you that may be traveling to the east, Interstate 84 at Cabbage Hill does have snow banked to the side and the road may be wet. You will want to use caution because of the grade of the pass. Plans to travel south or north on Interstate 5? You shouldn’t have to worry about anything but some passing showers on Tuesday. Dry time on Wednesday, which means you can travel with dry roads. Thanksgiving day travel will be dry to the south, but wet if you start driving towards Seattle. Siskiyou Summit was a vulnerable spot for Thanksgiving travel in 2020, but this year it should be smooth sailing.
If you are traveling east into areas of Idaho, especially driving north through Spokane and across into Montana, you may have more snow for your drive. The snow total forecast through noon on Thursday is projecting most of the snow through the higher elevations of Idaho. Much drier to the south, with no snow issues for that route to the south into California, as we discussed above.
Of course, if you’re flying out, you will just have to deal with busy airports. We are not anticipating any issues through the coast range routes, for the exception of wet roads on Tuesday. That is about it for snow this week. Travel back through the mountains this weekend shouldn’t be as snowy as what fell on Tuesday. They may be wet on Saturday, with snow levels bumping up above the passes. You will want to be more prepared for wet roads.
Swipe through the futurecast to see the timing of the rain that is going to drop in on Thanksgiving. For those of you that are day traveling, you will mainly avoid the rain until late Thursday. Wednesday should be a completely dry day for moving around. Thursday will start dry until the atmospheric river drops south late at night, closer to 10 or midnight. There are a few weather models that are projecting light rain showers to develop closer to the 7 p.m. hour Thursday. If that is the case, it will be light and it shouldn’t be a major issue. With the anticipation of a weak atmospheric river, I would expect it to take a little longer to reach us. For those of you that have Thanksgiving Day traditions in the morning, you will just have some clouds to worry about. Temperatures warming to the lower to mid 50s around the valley.
As far as rain goes for Thanksgiving day? According to the National Weather Service Climate Book we have a 60 percent chance for rain on Thanksgiving. The average comes out to 0.34 inches over the time frame of 1940 to 2019. The wettest year that we’ve had recent, was back to 2016 when we had nearly 2 inches of rain on Thanksgiving. We’ve had back-to-back years of no rain on Thanksgiving for Portland, which means we may be overdue. As we discussed above, there should be plenty of dry time in the morning and afternoon. We are likely instore for some rain late at night.
This is the stream of moisture that is expected to arrive late Thanksgiving night. This is going to be an atmospheric river that is weak but enough to get a good soaking in to the region. This will make the roads wet for Friday morning. That weak plume of moisture will drop south and it will impact the I-5 route to California on Friday. It will still not be cold enough for snowfall for the pass to the south.
