March 02, 2021

An Above Normal Winter Snowpack is Guaranteed!

The Northwest snowpack is now well above normal and with the latest model runs, it is pretty much guaranteed to stay that way through April 1.

And April 1 is the key date: the defined date for measuring the winter's snowy bounty before the spring melt season begins.

Snoqualmie Pass a Week Ago

Let me tell you why I am so optimistic.

We start off with a BIG snowpack, which is something you might expect in a La Nina year.  Every region of the state is above normal, with the western slopes of the Cascades averaging about 140% of normal as of March 2.   164% of normal in the Olympics.


But if you really want to be impressed, consider a few specific locations.

Take Stevens Pass in the central WA Cascades (below).  The light blue line is the normal snowpack through the year (actually SWE:  snow water equivalent) and the dark blue line is this year.  

Wow.  The snowpack went CRAZY in February, going from near normal to WAY above normal.   In fact, far exceeding the normal annual maximum in early April.


What about White Pass on the eastern side of the Cascades.  Prepare yourself.  Even MORE above normal. This February has been extraordinary.  No wonder skiers are going crazy.


Another way to explore how good the snowpack is this year is to use the new online app provided by the Office of the Washington State Climatologist.  Here is their comparison of this year's SNOWDEPTH with those of previous years for Stevens Pass.  The blue line is a long-term average.  

This is one of the best years on record for the beginning of March at this location


And the snowy fun is not over.   Let's look at the snow forecast from the world's best:  the European Center's extended-range forecast.   For the next month it is going for COLDER than normal conditions (see map). Blue colors naturally.

And there is bountiful snow forecast for the next month as well (see below).  Even California gets in on the massive snow action.

All in all, very good news.  Plenty of snow for recreation.  Plenty of snow to provide water this summer.  Plenty of snow to delay high-elevation wildfires.  And another example of why the "end of snowpack" fearmongering of 15-20 years ago was both bad forecasting and bad science.  

Global warm will reduce snowpack this century, but the effects are still subtle and small at this point.


16 comments:

  1. Great news for the reservoirs. Only negative is that it delays the higher elevation hiking(like Rainier, Baker, North Cascades, St Helens etc) but hopefully the ski season is extended in some places.

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  2. Once again, Cliff is the lone voice of sanity amongst the MSM. Only yesterday the local weathercasters here were watning that despite all of the recent snow in NW Oregon, we were still barely at normal at this juncture.

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    1. Oregon DOES get different conditions than WA, take a look at the Oregon maps.

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    2. What applies to one area doesn't necessarily apply to a nearby area. Your local weathercasters aren't wrong. It's a different story in OR. It's not terrible, but certainly not as above normal as most WA basins. Link: https://www.wcc.nrcs.usda.gov/ftpref/data/water/wcs/gis/maps/or_swepctnormal_update.pdf

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    3. Good observation. Who was it? I think I will organize my own culture cancel against them.

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    4. Good observation. Who was it? Where is the cancel culture when you need them?

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    5. Most of OR is above normal, that is a fact. Additionally, if you've followed Portland forecasters over the past decade you'd be well aware that every year they've consistently under reported anything positive regarding the snowpack and water situation, no matter the reality on the ground.

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    6. "Your local weathercasters aren't wrong".

      Yes they are, are you serious? I have seen that whole map yellow in previous years and there was no crisis. To claim otherwise while 75% of the state is above normal - and in some cases wildly above normal - is ludicrous.

      But as Eric points out, where's the fear in that?

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  3. White Pass is on the Cascade crest, not on the eastern side. Water on its west side flows to the Cowlitz. I’ll grant you that the crest is relatively far east in that part of the Cascades though.

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  4. Wait a minute, wait a minute... is that a fantasy lowland snow map I see? Snow lovers can only wish (though it'll never happen)...

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  5. How do you know he is sane Eric?

    What he neglects to add what has long been no secret which is that snowpack won't be a big net loss.......

    in Washington Cascades and the BC Coast ranges. Unfortunately, they call it global warming, not just Washington (or Texas?) warming

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    1. "has long been no secret which is that snowpack won't be a big net loss"

      Yes, on this blog and this blog only. But please go ahead and tell the scientists back in the 2000's - who were fired or threatened for saying exactly that - that it's "long been no secret". What a joke.

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  6. None of it matters. Next fall when November snowpack is at 6 inches and the normal is 10 inches there will be the same voices screaming that global warming has decimated the snowpack and it is “very concerning” and mostly… everyone needs to be in fear because we are at 60% of snowpack and this is the future and “Mother Nature has conspired against us” and we’re in a “wet drought” and “Cascade snowpack is collapsing” etc. etc. And then they might even fire any scientist who disagrees with them, or make the attempt to, and maybe call them racist along the way.

    Because all of those examples are real. All of them have happened in the last 20 years and all of them have been complete lies with the purpose of destroying scientific dissent, and exactly zero of the people doing this have been held accountable.

    So just know this year is great, but really who cares. We’re 6 months away from the next guaranteed drought crisis. Enjoy the truth while it lasts.

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  7. Cliff I want to add here I don’t understand why you are understating the viciousness of the last 20 years toward anyone disagreeing with the “Collapsing Cascade Snowpack” theme.

    Back in the early 2000’s they specifically chose the early 1950’s – years of massive snowpack – to show that snowpack was declining. Well here we are in 2021. Can we choose the 70’s now? It’s the exact same timeframe, 50 years.

    So look at that, snowpack has increased exponentially in the last 50 years, I mean off the charts. It’s global cooling on a massive scale!!! But, you know, that would be dishonest, wouldn’t it?

    The credibility of science on this subject has been destroyed in the last 20 years. It’s a joke to anyone paying attention.

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  8. If the trend during the past twenty years of cooling in much of the Western US and warming in much of the Eastern US continues, it seems as if before global warming reduces snowpack later this century there might be a tendency to have years with greater snowpack than average. To the extent that the warming trend in the Eastern US and the trend for the NAO index to become more positive over the past thirty years at the fastest rate ever observed corresponds to a reduced tendency for an strong upper level low to be near Hudson Bay during winter, this would reduce any related tendency for an upper level high over the Western US to result in winters in the Pacific Northwest being warmer and drier than average.

    A study published in the most recent issue of Science Magazine seems to indicate the possibility that recent trends related to atmospheric circulation may be partly the result of greater ozone loss in the stratosphere as the magnetic field weakens. Data for the study came from the rings of fossilized kauri trees up to 1700 years old that had been alive when the geomagnetic field was greatly weakened during the Laschamp excursion. The possibility that the current weakening of the magnetic field might be affecting weather patterns was mentioned without specifying how climate change may be related. An indication of this possibility is that during the past forty years there has been a trend for the polar vortex to be weaker in early winter and stronger in late winter. This might partially be explained by that increasing UV as a result of ozone loss contributes to additional melting of ice during summer which tends to weaken the polar vortex in early winter since it takes longer for freezing to occur while because of additional ozone loss the polar vortex tends to be stronger in late winter. The recent paper published by NASA scientists which discusses evidence that UV-C may now be reaching the Earth's surface along with increasing amounts of UV-B and related positive feedback indicates that melting of ice may increase more rapidly that previously expected.

    To the extent that negative radiative forcing related to ozone loss in the stratosphere increases relative to other influences which determine the location of the polar vortex, as the sun moves north rapid cooling in the stratosphere in different locations could at times cause the location of the polar vortex to change rapidly. An indication that this could strongly influence weather patterns is that in 2019 after weakening of the polar vortex caused extreme cold east of the Rockies, the Arctic Oscillation after being negative rapidly became positive as the strongest part of the polar vortex reestablished farther north. Similar changes also occurred last month.

    With an increase in radiative forcing related to stratospheric cooling relative the tendency for the polar vortex to be near Hudson Bay, the polar vortex would tend to less often be near Hudson Bay. Since during late winter when the tendency for rapid ozone loss is strongest historically there has been the greatest tendency for an upper level low near Hudson Bay to result in only the Central US and Eastern US to be downstream during arctic outbreaks, any reduction in such a tendency would increase the chance for lowland snow in the Seattle area in February and may possibly be related to that in three of the past five years there has been a major lowland snow event in Seattle during February. Further support for this possibility comes from that while historically in late winter it has been unlikely for Seattle to even get any snow right after a major arctic outbreak east of the Rockies, in 2019 within a few days after the extreme cold east of the Rockies shortwaves moving down the coast caused multiple snowfalls in Seattle which histrically has been more likely in early winter before there is a stronger tendency for a strong upper level low to be near Hudson Bay.

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  9. To add to the comments I made on Thursday related to the paper published in 2007 by NASA scientists which discusses evidence that UV-C may now be reaching the Earth's surface along with larger amounts of UV-B than previously expected, the additional amount of trees that are harmed and killed as a result of this may be related to the increase in forest fires in northern regions which adds to the amount of CO2 in the atmosphere. This would tend to add to the positive feedback which results from additional melting of ice. What was indicated by the evidence was confirmed by other scientists after NASA never followed up on the study. I expect that the reason for this might be that it indicates that a large part of the cause of climate change may be other than manmade CO2.

    To the extent that negative radiative forcing related to greater rapid ozone loss in the stratosphere rapidly causes different parts of the polar vortex to strengthen, related changes in atmospheric circulation could cause the part of the polar vortex which was previously strongest to weaken rapidly and collapse as sudden stratospheric warming occurred. It might be that part of the reason why this has not caused the jetstream to become any more wavy on average is that this would tend to result in relatively brief periods of very noticeable waviness which could be offset by longer periods in which the jet stream is less noticably a little less wavy than average.

    The map in the Feb. 17 post with Feb.15 temperature anomalies shows an example of how when arctic air flows into the Western US there is a tendency for the Southeastern US to become warmer for a while as an upper level ridge builds before some of the cold air moves east. To the extent that this type of weather pattern occurs more frequently it would be part of the reason why the Eastern US has been warming. If the current trend continues during arctic outbreaks the coldest air will more often flow into Texas than when it previously more often flowed farther east. Since in addition to any such tendency there has been a warming trend in Texas, at least for a while this might tend to cause Texas Northers to result in more extreme changes in temperature.

    The trend for the Arctic Oscillation index to be more positive may to some degree also support the possibility of lowland snow in Seattle in late winter relative to early winter. In early the winter before the Arctic is coldest lowland snow in Seattle has historically tended to occur when the AO is somewhat negative as arctic air flows close to directly from the north ahead of a strong upper level ridge off the coast. However some of the largest snowfalls and coldest weather in late winter have occured when the AO was strongly positive as was the case in 1989 during the Feb. 1 and March 1 snowfalls. It seems as if this may be related to that in late winter the arctic is cold enough that very cold air can cover a large part of Canada. At such times a negative AO would tend to correspond to arctic air flowing east of the Rockies before some of the arctic air could move far enough west and before enough arctic air could flow through the Fraser Valley to cause snow. However an AO that is positive but not so strongly positive that it corresponds arctic air remaining to the north allows for time for the coldest part of the polar vortex to move farther to the north or west of Hudson Bay as some of the arctic air moves closer to the Western US than to the Eastern US. Snowfalls can then result as shortwaves move down the coast as cold air flows through the Fraser Valley.

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