March 01, 2024

Massive Area of Cold Air is Over the Pacific Northwest and It Not Going Away

 The infrared satellite this afternoon was startling

Extreme cold air has spread out of Alaska and over the Gulf of Alaska and the northeastern Pacific resulting in a massive field of thunderstorms and convective clouds (see below).  

You the white broken clouds offshore?  That is what I am talking about!

 

The atmosphere over the Pacific is very, very unstable due to cold air moving over warm water.  This causes a large change in temperature with height that causes the atmosphere to convect, not unlike the churning oatmeal in a saucepan over a hot burner.

A very deep upper-level trough of low perssure is over the northeast Pacific and temperatures (below) are well below normal (blue colors in the map below for around 5000 ft)


SeaTac only warmed to 41F today, ELEVEN degrees below normal.  Many of you have seen snowflakes mixed in with rain today, and a large amount of snow has fallen in the mountains, where the snowpack is increasing rapidly.

The latest forecasts suggest we are in for an unusually cold first half of March.  Consider the highly skillful European Ensemble forecast system in which many forecasts are combined.    For the next ten days, it is predicting much colder than normal conditions over the ENTIRE western U.S. (blue and green colors)


The same system is forecast for large amounts of snow over the same period (10 days) from California to British Columbia.


The next 48 hours should bring a great deal of snow to the coast and the Olympics---with the Olympics being exactly the mountain area that needs it (see below).

I believe there is a good chance that the snowpack will be close to normal by the end of the month, but time will tell.





13 comments:

  1. It's interesting how weather will always be weather - you never really know what is around the corner. As late as a week or so ago, the TV weather forecasters were still downplaying the possibility of getting a "normal" snow pack - even with all the National Weather forecast information pointing in that direction.

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  2. Snowing in the Okanagan. AGAIN

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  3. NWAC publishes a snow depth climatology summary on the 1st and 15th of every month through the winter. Yesterday's report actually shows three locations (Paradise, Stampede Pass, and Mt Hood Meadows) now above the 30 year average. A dramatic improvement all around since the middle of the month!
    https://data.nwac.us/CLISNO/clisno.pdf

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  4. So glad to here your optimism on snowpack. Others, from the NWS, according to a capital press article, say it is "unlikely" it will rebound. Thus talking about water shortages and fire danger. While it is prudent to plan for worse case scenarios, to talk as they are "likely" is reckless. We may have a very cool wet summer. No one knows.

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  5. From the Blancolirio world headquarters located in Nevada County, California, polymath extraordinaire Juan Browne gives us a useful analysis of the weather now affecting central California, plus additional commentary on the wildfires in Texas:

    CA Winter Storm Report, Oroville Update, and Texas Wildfires

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  6. While the recent snowfall will help it may be too late in the season to expect many areas to reach "normal" snowpack levels. Some higher elevation stations such as Park Cr. Ridge and Lyman Lake in the Lake Chelan watershed are still 15 to 20 inches of water equivalent below normal for the first of March. These higher elevation areas could pick up more this month but the lower elevations will have increasingly less chance that precip. will fall as snow and will begin to lose snow on the warmer days. Unless there is a prolonged cold, moist period, I believe nearly all areas of Washington will end up on the short side by the end of the snow season.

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    1. Take a look at the model forecasts.... cold and wet.

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    2. I am getting tired of this though. We haven't really had one of those "false springs" we sometimes get this time of year, with temps in the mid 50's and sunny for a few days. And either my crocuses are late, or the rabbits ate most of them.

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  7. Many natural aspects, such as precipitation, seem to have a large variance compared to, say, height of males at high school graduation.
    In the real world, snow depth and Snow Water Equivalent (SWE) cannot follow the Lake Wobegon principle.
    The SNOTEL area I am in is called Upper Yakima and has 7 sites. As of Sunday morning March 3rd, it has an 83% of median SWE. At the moment it is not snowing in this area, but Crystal Mountain (50 mi. east of me) has snow.
    The Great State of Washington will survive the natural elements.

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  8. As of today the Mt snowpack in the Olympics and northern cascades is only around 50% of normal, so much for reaching that normal snow pack by the end of March and with a hot summer on the way I am very concerned.

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  9. This comment has been removed by the author.

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  10. I appreciate the models because this narrative helps make sense of what my Google weather app shows me.

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