Temperatures are at/below freezing through the entire Columbia River Gorge at this hour:
And now a wall of rain is moving into the Portland metro area as a very juicy Pacific system moves inland:
This is going to be a fast-moving storm with moderate to heavy precipitation from now until around 3am, then we pretty much go dry until tomorrow afternoon.
Let’s hit the highlights first:
- All rain metro area EXCEPT temps at freezing upper parts of Troutdale/Camas/Washougal/Gresham so there will be freezing on objects…likely SLIGHTLY too warm for freezing on roads out there. But it’s going to be close!
- Western Gorge west of Bonneville Dam could see 1/2″ ice glazing by 4am when the freezing rain stops.
- East of Bonneville Dam likely a snow/ice pellet mix, maybe 1-3″ snow accumulation, then a glazing of ice on top of that possible once precip stops before daybreak
- Slow thawing during the day tomorrow, but I-84 will be a mess tonight and tomorrow morning
You notice we’ve inserted snow into the forecast. Observations from Red Hill and Ausperger Mtn. at 3-4,500′ show the cold pool is up to at least 4,000′ thick still! The Wasco profiler east of The Dalles also shows the top of the cold air up around 4,000′ too. Yet by the time the cold airmass reaches the Troutdale profiler it’s only around 1,500′ thick. Cool stuff eh?
So it’ll start as snow east of Bonneville most likely.
By the way, the east wind continues tomorrow, although a bit reduced, then a switch to southwest wind Thursday afternoon should make it into the Gorge for the big warmup.
Chief Meteorologist Mark Nelsen