April 09, 2022

The Last Chance for Lowland Snow

 If you are living in western Washington, the next 48-h will afford your last chance to see some falling snowflakes.

But don't start thinking about sledding and snowballs--there will be no lowland accumulation.

Although it is unusual, snow has fallen and accumulated over the Washington lowlands in April, something shown by plots of extreme snowfall amounts in Seattle and Bellingham below.



We have a chance this weekend and Monday....but then it will turn too warm for the remainder of the month.

The freezing level over us right now over Puget Sound is now around 1700 ft.  Colder than freezing above and warmer than freezing below.  Most precipitation starts as snow high up and takes about 1000 ft to melt when it falls into above-freezing temperatures.

Thus, right now, wet snow could fall to around 700 ft.

The atmosphere will cool a bit tonight and precipitation can cause the atmosphere to cool from melting and evaporation.  So snowflakes will be able to descend lower tonight.

As shown by the forecast surface weather map below for 5 AM Sunday morning, cool air (blue colors) will be over the region.  And if you look closely, you can see a low-pressure center over the southern tip of Vancouver Island.  That weak disturbance will result in light rain...with a few embedded snowflakes.


Here is the forecast snowfall through 5 PM Sunday.  Some very light amounts from the mixed snowflakes.


But look at the predicted snowdepth at the same time (below).  The lowlands are bare--but lots in the mountains.


But snow lovers have a second chance.  A much stronger system will approach our region and head into northern Oregon.  Powerful winds will spread over western Oregon and cold air will push out of the Fraser Valley of BC.  


This system will bring another chance of snow, even with temperatures being marginal.  Take a look at the 24h snowfall total ending 5 PM Monday.  Some locations in SW Washington might see some flakes.


Anyway, no one is going to call this the great April snowstorm....but it will serve to remind us that the atmosphere can be quite cool in April.    And this snow event will freshen the Cascades snowpack, which is good for many reasons.  No early wildfires this year.






4 comments:

  1. It is snowing like crazy in Snohomish. Huge flakes, 35°

    ReplyDelete
  2. Snowing like crazy in Snohomish. Huge flakes and 35°

    ReplyDelete
  3. It would be nice if this recent snowfall acculmulation in the Oregon Cascades would help alleviate the constant bloviating about how the entire state is in a severe drought and all hell will break loose this summer. Granted, the southern part of the state will be in drier conditions than normal, but just once could calmer heads prevail in the MSM?

    ReplyDelete
  4. The freezing level chart, wet snow could fall to around 700 ft, helps to clear up. Why the Skagit valley is generally snow free, yet the surrounding foothills, quite a few have roads to houses, get snow.

    ReplyDelete

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