No Snow Tuesday, But Wednesday Looks…
Updated 11:20pm Monday
I had a nice birthday dinner with my extended family tonight and arrived home to “some” local TV stations and “some” print media outlets getting ready for “storm team coverage.” Other private and public forecasters were also calling for snow to sea level right in time for the evening commute Tuesday. A few forecasters are calling for no snow tomorrow at all. In the end, we all look at the same data, yet it is how we interpret this data that “makes” or “breaks” a snow forecast right down on the valley floor. This event will be no different. Since it is time to make a final call, here is mine —
The big message on both the 12z models today and the 0z models tonight is loud and clear —- “SNOW WILL NOT STICK ON THE VALLEY FLOOR TUESDAY!” The evening commute around Portland is not likely to see any major weather related problems. Model soundings this evening show that the air above Portland will warm enough tomorrow to lift the snow level off the valley floor by the time the moisture arrives midday. I have been asked by several media outlets for my take on tomorrow (Tuesday) and they all received the same answer, “no sticking snow on the valley floor for Tuesday evening’s commute.” As we saw last weekend, sticking snow will once again remain at or above 1,000ft on Tuesday. However, wet snowflakes will likely mix in all the way down to the valley floor at times on Wednesday morning as the latest models show additional cooling after the front passes through Tuesday night and another round of moisture is slated to come in early Wednesday morning. 0z models out this evening continue to show a rather chilly day on Wednesday with plenty of steady precipitation. That could bring the snow level down to the valley floor early Wednesday morning underneath those heavier / steady showers. In fact, Wednesday looks like the best threat for valley snow when compared to Tuesday. So, let’s take it one step at a time:
Tuesday — model soundings over Portland are not cold enough to support snow Tuesday during the evening commute. Models also indicate that the track of the low will stay north of Portland, drawing up southerly winds that will keep snow off of the valley floor tomorrow (Tuesday). There is a small amount of easterly gradient that will set up and pull a little cooler air down the gorge on Tuesday, but it will not be enough to support an area-wide snow event. This will be very similar to this past weekend with snow sticking in the hills but NOT right down here on the valley floor.
Wednesday — the main front will have passed by with lots of colder air behind it. Additional showers will flood the area on Wednesday morning. These will likely be snow showers at ALL elevations Wednesday morning, followed by a mix of rain and snow in the afternoon. There is one particular area of consolidated precipitation that could bring snow all the way down to the valley floor Wednesday morning that models are starting to pick up on. Also, temperatures will be chilly on Wednesday with highs barely making 40 degrees if we see consolidated snow showers across all areas.
BOTTOM LINE — Don’t panic about a snowy evening commute Tuesday. No valley floor snow Tuesday. No accumulations below 1,000ft on Tuesday. Snow showers likely at all elevations on Wednesday morning with a mix in the afternoon. Some light accumulations possible at all elevations Wednesday morning if you get caught under a heavier snow shower. 1-2″ inches are likely above 1,000ft on Wednesday morning. The Cascades are going to see an additional 15-20″ of snow through Thursday. More great powder for the ski slopes! Get up there and enjoy it!
Finally, the Oregon AMS meeting scheduled for Tuesday night is still “ON” at the KPTV studios in Beaverton. We hope to see some of you there for that! We will also take a good look at the latest model data and see if a more consolidated snow threat still exists for Wednesday morning.
Stay tuned!
Steve Pierce
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