There has been a lot of talk about the possibilities for snow in the lowlands of Western Washington in the next week to two weeks, and the chances of an Arctic outbreak with very cold air plunging into Western Washington are indeed increasing beginning around Sunday, Jan. 12.
However, as is the case almost always with the forecast more than five days out -- the details as to snowfall, and where, are uncertain.
So, through this work week, expect low-elevation rain with mountain snow levels falling to 1,000 to 2,000 feet by Wednesday after a warmer Tuesday.
By Thursday morning, we could have some light snow below 1,000 feet in elevation but this does not look to be significant. We’ll probably warm up on Thursday afternoon into Friday morning enough that snow will be probable above 1,500 feet in elevation -- exclusively a high-foothills affair.
Over the weekend, colder air will probably start moving in with snow levels dropping below 1,000 feet by Sunday morning and lasting into Monday.
If it’s going to be cold enough for snow down to near or at sea level, then why might we not have a big snow event?
It’s often difficult to get the coldest airmasses from interior Canada into the state west of the Cascades without drying the air near the surface so much that snowflakes are “eaten up” by the dry air as they fall. In fact, that could well happen by Monday or so of next week -- high temperatures in the 30s but drier air not allowing for a lot of snow.
To get a lot of snow to fall, it really needs to be a “Goldilocks” setup -- not too frigid an airmass (which is generally going to be too dry for major snow) but temperatures just right to get lower snow levels without just totally drying out the atmosphere and forcing only an outbreak of chapped lips.
That could well be the scenario, and we won’t know for sure until closer to the weekend and next week. But even if we get an extended stretch of very cold air -- lasting many days next week -- that could actually hold a better chance for accumulating lowland snow for when the cold eventually breaks!
In other words, no big snow when it gets cold, but snow when it starts to get warmer.
If a very cold airmass gets locked into place, moisture and warmer air is often necessary to “break out” of the deep freeze. Often, coming back out of a cold airmass holds the better chance for lowland snow.
But that would be well more than a week away!
So the bottom line right now is that the outlook for lower snow levels and wintry precipitation is tantalizing for next week but whether we would have any significant impacts -- or any impacts in the lowlands at all -- is still just impossible to determine right now.
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