Some nice alliteration in that title eh? Ridiculous I know, but I couldn’t stop myself on this Saturday morning at 11am.
Luckily we avoided an ice storm for MOST of the metro area yesterday and most of the forecast in the end worked out just fine. Tons of ice for the morning commute and then by the afternoon most areas were clear except right around/in the Gorge and up in the higher hills. Of course the cold air lingered longer than expected right along the Columbia River…PDX Airport ended up with .30″ ice and poor Troutdale had .81″ once it was done just before sunrise. That’s the 4th ice storm along the Columbia River this winter!
Let’s add it up: We’ve had 2 snow/ice events in December, 3 in January, and now 1 in February. That’s a total of 6 times we’ve dealt with ice and/or snow (or a combo) so far this winter right here in the city. We haven’t seen a winter like this in the 26 years I’ve been forecasting in Portland. That doesn’t count 2-3 other wet snow events in the higher hills too.
Tomorrow through Monday morning will likely be #7. This time you can forget freezing rain, it’s all about 32-33 degree snow under a calm wind.
What’s the plan?
It’s going to rain a LOT Sunday and Sunday night west of the Cascades where most of us live as a stationary front sits along a line from near Newport to The Dalles. Subtropical moisture will be riding up along that front = juicy with lots of precipitation.
Check out model forecasts of total precipitation the next few days, most of it is done by Monday morning:
A huge soaker right? In fact there could even be some localized flooding with this kind if rain intensity. During the daytime Sunday that front is hung up somewhere across the NW corner of Oregon. The location is slightly different on each of our models; here’s the ECMWF temperature plot at 4pm (middle of Super Bowl):
50s in the southern Willamette Valley, but cold enough for a very heavy/wet snow from the Portland metro area north! Is this rare? Yes, the last time I’ve seen a situation like this was March 21st, 2012, the “Spring Break Surprise”. Actually it was a couple of days before spring break started, but close enough for a clever name. Nice pic…
That was a big snowstorm in the central/south Willamette Valley and is now known as the latest snowfall ever at PDX Airport. You can see looking at that map how a very slight movement north or south will make a HUGE difference in snowfall totals (and who gets a heavy cold rain instead) for the daylight hours Sunday. Now Sunday evening and night the whole front shifts south as a cold front, which means probably ALL of us in the western valleys get at least some snow. The big question is who gets pounded with a heavy wet snow and who gets just heavy rain tomorrow during the day. The short answer is: We don’t know for sure yet, but north of Portland is looking like the surest bet for daytime snow at this moment. In this pattern the coastline can get the heavy snow too since there is no warming onshore wind.
All areas west of the Cascades in the lowest elevations (including the coastline) see steady rain to start Sunday morning
Many areas from Portland/Tillamook north (including Astoria & Longview) may switch over to a heavy/wet 32/33 degree snowfall the rest of the day with many inches possible
The Portland metro area MAY see a switch over to snow during the day; best chance for that will be as you go up in elevation into the hills. We’ll know more after evening models come in.
South of the metro area a switch to snow is less likely during the daylight hours, but still a possibility
All areas at the lowest elevations along I-5 from Olympia to Albany will likely see at least some snow on the ground by late Sunday night and for the Monday AM commute since we’ll all cool close to 32 degrees
There is a high potential for a heavy/wet snow storm anywhere above 1,000′ in SW Washington and NW Oregon. There will be locations that see 10-20″!
There is a decent potential that some location somewhere along the I-5 corridor at the valley floor (somewhere between Albany & Olympia) and some city along the coast north of Pacific City will see a foot of snow on the ground by Monday morning. We just don’t know exactly where at this point.
Due to the potential that just about any area could see the big snow, the NWS has issued a Winter Storm Watch for all of us westside. That doesn’t mean everyone is going to get heavy snow, but it’s just a “hey, keep an eye on the forecast” type of watch.
Because of the possibility we could have some sort of historic heavy wet snowstorm in the lowlands, I’ll be working tonight on the 10pm newscast. Of course I’ll be in tomorrow as well.
Stay tuned because it’s going to be a wild ride for some of us the next 48 hours!
My guess is that you’ve seen different maps on social media floating around showing snow totals from models. I’ve included a bunch here. They are all different because each model has a slightly different location for the front, a low passing by to the south Sunday evening, and physics. They each calculate snow in a different way too. You get the idea…someone is going to get nailed by a big dumping of snow! By the way, the Cascades have several feet coming too.
Chief Meteorologist Mark Nelsen