A snowstorm is on the way for the central and south Willamette Valley and a good chunk of the Oregon Coast! I can hear the collective shouts of dismay from Portland area kids, teachers, and weather geeks. Too bad for us. Maybe we’ll at least get some flurries…
This morning models have come into agreement with our forecast…always good when that happens! They are all keeping just about all snowfall well south of the Portland metro area late tonight and Friday morning. That doesn’t mean we couldn’t get flurries anywhere else, but any “impact snow” (enough to turn roads slick) should stay south of the metro area.
Maybe a slightly later start than previously expected both at the Coast and inland. Sometime after 3am at the Coast and 6-7am in the valley from Salem south.
- High clouds thicken up today, as a result our coldest day so far, just creeping a few degrees above freezing
- Snow will spread onto the beaches (yes, the coastline!) late tonight and inland by sunrise tomorrow.
- At this point it appears accumulating snow will most likely stay SOUTH of a line from about Seaside to Newberg to Mt. Hood. Yes, that means just flurries at best for the Portland metro area late tonight and Friday morning.
- 1-3″ is possible from Tillamook to Newport on the coast, and in the Valley from McMinnville to Salem and south during this time (Friday AM)
- 2-4″ is possible Albany, Corvallis, and Eugene (south Valley)
- A dusting to 1″ could make it as far north as Forest Grove and Banks near the Coast Range…maybe
- Avoid travel south on I-5 all day tomorrow between Salem and Eugene
- Strong Wind Metro Area Friday: Gusty east wind pours out of the Gorge tomorrow, bringing a frigid arctic airmass west of the Cascades, the coldest we’ve seen in 4 years. Between the wind and colder temps, the metro area is going to feel much colder tomorrow than the past few days. We could see 40-50 mph gusts from the east-northeast central and east side of the metro area, and up into parts of Clark County too. So some power outages are possible during the day. The wind will dramatically die off Saturay though and be calm by Saturday night. High temps probably won’t rise above freezing Friday through Sunday; our coldest weekend we’ve seen in a long time…but sunny!
What has changed today? Not much, you’ll notice the highlights are almost the same as yesterday’s info. Luckily, our RPM model has finally come into better agreement with all others. And timing seems to have slowed down a couple of hours too. Here is the latest snowfall forecast from our RPM model:
And the WRF-GFS:
Are you a casual observer of the weather and don’t spend every waking hour staring at weather maps? Then keep in mind that you generally shouldn’t read models like this literally. For example on the lower map don’t assume 3″ of snow is coming for Tillamook and nothing for Pacific City. Instead note the big picture that then northern extent of the snow is around Astoria and the southern edge is around Newport.
I think it’s interesting to note the placement of heaviest snow in the Willamette Valley is almost exactly the same as what we saw during the “pre-Spring Break” snow in 2012. The snow begins accumulating somewhere south of Wilsonville and is heaviest in the Albany to Eugene stretch. It sure won’t feel the same though! This time it’ll be well below freezing, roads will stay icy, and with a northerly breeze it’ll even be blowing around a bit.
Tomorrow looks very cold across the entire area, even if temps are warmer, it’ll feel as cold as 4 years ago during the 2009 arctic blast due to a strong east wind being pulled out of the Gorge by the surface low tracking down the coastline.
Strong wind may be an issue around metro area tomorrow. Take a look at the WRF-GFS cross section:
When I see 50kts getting that close to the surface that’s impressive. Gusts 40-50 mph look possible not only in the usual east wind spots but also in parts of Clark county and the west hills. This isn’t a classic downslope wind event; that happens when we have warm air above with an inversion and the flow is capped near the crest of the Cascades. Still, who wants to lose power on a day the temp has trouble getting above freezing?
That east wind will go calm by Saturday night and Sunday morning as high pressure develops directly overhead. This, along with the bitterly cold airmass that just moved in, will lead to our coldest nights since 2009. In the areas with snow cover in the valley, Saturday and Sunday nights will probably be the coldest since the 1998 cold wave. Lots of single digits south of Salem assuming the snow arrives.
Chief Meteorologist Mark Nelsen