It may come as a shock to some, but there has been little trend in Northwest snowpack over the past 40 years. This is true even though the globe is slowly warming due to increased greenhouse gases (such as CO2 and methane).
Plenty of snow still at Paradise on Mt. Rainier
Research meteorologist Mark Albright, who for years was Washington State Climatologist, has plotted the April 1 Northwest snowpack (WA, OR, ID, western MT) over the past 41 years (1984-2025).
The plot below shows SWE--Snow Water Equivalent-- depth of liquid water that would remain if a column of snow were melted.
The horizontal solid line is the long-term annual average (19 inches), and the red line shows a 5-year running mean average.
This year was above the average. There is very little suggestion of long-term decline.
Although this year was near normal for the entire region, that does not mean every location was near normal. As shown below, the snowpack's water content in individual areas varied substantially.
Most of Oregon is above normal. Southern WA is above normal, the central Cascades are below normal, and the Olympics are near normal. Such regional variation is well...quite normal.
The snowpack is good enough that snowmelt has driven the Yakima Reservoir levels (blue line) above last year's.
Looking forward, we have a dry week ahead, but things will get wet next week, with substantial precipitation expected (see below).
So, at this point in time, there is no reason to expect any water "emergencies" or droughts as we go into the summer.
________________________
I will be talking at the UW Olympic Natural Resources Center at 7 PM on Tuesday, May 6.
Open to all and free. My topic will be "The Great Storms of the Northwest Coast." They will zoom it as well.
_______
Announcement
I will hold a special online Zoom session at 10 AM on Saturday for Patreon supporters. Will answer questions, talk about the spring forecast, and perhaps discuss the current NOAA situation.
.png)
I believe most of the measuring sites are at higher elevations. We lack data on mid-elevation snow. Around me, from visual observation, mid-elevation snow is thinner mid-winter, and gone earlier than it used to be. This while the Sno-Tels show 'normal' pack, as you said.
ReplyDeleteThe current snowpack water content levels around Seattle, Wenatchee, and Ellensburg are looking rather low. Will this pose any problems for this year's water supplies in those areas? Also, will it increase the wildfire risk in those areas, especially early in the season?
ReplyDeleteA few questions:
ReplyDelete1. Your data shows that the Yakima Reservoir level is well below average. Why does it matter that it's just a tad above last year, and only for the past couple days?
2. Why did you choose the Yakima reservoir among the many in the state?
3. Why did you choose 1984 as the start date for your analysis? The available data goes back to 1955. On the EPA site which reports ALL of the data, a strong downward trend is visible throughout most of the American west, and most notably in the Pacific Northwest.
(1) It will be substantially above last year...and last year the impacts were small (2) Yakima is the lowest reservoir...many of the others are normal or above normal (like Seattle). Showing the worst case (3) I did not choose it, Mark Albright did. I believe data available decline rapidly for earlier years. In any case, 40 years is long enough to see the recent trend. CA snowpack has been up recently, by the way.
DeleteIn the western USA, the snotel network was largely established between 1979 - 1984. In Washington State only a few sites existed prior to 1984. I use only sites with a complete record over the period chosen for analysis.
DeleteInteresting analysis; thanks for sharing. I'm looking forward to zooming in on Great NW Storms tomorrow.
ReplyDeleteHope he talks substantially about the awesome 1962 Columbus Day event!. The eye of that monster storm (a CAT 2 hurricane by today's standard) raced up Northward along the coast, until veering into Vancouver Island as it finally fizzled out. It actually had impacted Northern California, and stayed very powerful when strafing the Oregon Coastline....The huge "pinwheel" effect turned Puget Sound into a corridor of nastiness, due to being semi-enclosed by our two mountain ranges. Seattle proper endured 50mph steady winds, with gusts into the 80s...a 100+ gust was recorded in Renton, and other places recorded gusts well into the 90s! I was 16 years old, trying to deliver my newspapers, when that storm tackled my from behind, as I was walking North between N85th and N 90th. a half-mile or so from Green Lake. I will never forget that titanic storm! It blew hard, for a good four hours. Nothing quite like it has happened in this area, although a few more locally focused "bomb cyclones" have briefly shown up, over the last 63 years.
DeleteHope it rains. Have water on at camp gound already 2300' elevation as my grass was dry. Usually wait until memorial day campping trip to do that. And here in Okanogan Valley the cheat grass grew, seeded out and turning brown already. At least didn't grow tall.
ReplyDeleteWhat is the explanation for the disappearing and receding glaciers in WA state.
ReplyDeleteI really enjoy reading your blog. Thank you for all the time you put into it.
Arthur . .
Snowpack responses to the temperature and precipitation of the past winter, while glaciers respond to decadal changes, some natural and some caused by humans. I have done several blogs on glaciers and their changes over time, such as:https://cliffmass.blogspot.com/2023/06/the-real-story-about-melting-mount.html
DeleteWhat is going on with the z value anomaly correlation with the GFS model overly the last 1-2 months? Lack of weather balloon data? NOAA cuts? AIFS model in the lead now even over GFS and ECMWF (non-AI). Something seems off and perhaps intentional. To the point now where I won't even look at the GFS for planning outdoor activities. Used to have .94-.96 z values now in the upper 80s. Yikes.
ReplyDeleteThis doesn't surprise me. Living here near Mt Baker, having observed and recorded weather, water, and snow for years (decades) I've been puzzled by any number of declarations and conclusions that seem disconnected from reality. Variability is a very natural thing here, and over time there I've seen very little in the way of certainty where it comes to 'trend.' Meanwhile, the legislature now demands that we plan for change. I'm wrestling with that, a nearly impossible task given that swings are normal.
ReplyDeleteMass this rain needs to stop? You want to mow my lawns? I didn’t think so
ReplyDeleteWhile snowpack SWE is the same.....what about snowmelt? Is that the same? Snowmelt usually starts around April 15th of each year. Is the speed faster, slower, or the same?
ReplyDeleteThanks Cliff, for highlighting that there is not a consistent trend in regional snowpack- something I often get major push back for noting. I do miss the well above average snowpack cycle of ~15 yrs ago- it'll be good to see one of those again! Re the Yakima this year, its worth an update. While our reservoir storage has recently caught up to last years thanks to the rapid melt of an average April 1 snowpack, last years was one of the lowest levels ever, and our current (not april 1) snowpack is now below last year's. We're on track to end up with a similar water supply shortage (50-odd% supply to the junior irrigators), and while likely not catastrophe, it is far from trivial and will be a serious hardship for some growers. You are of course quite right that this year we do not have a meteorological drought (though it's been a dry few weeks to mushroom hunter's dismay)- the issue is that when the reservoirs get run as low as they have been the last two years, it takes a well-above average year to make up the deficit in water storage. Only one of our major reservoirs is predicted to come near filling this year, and even if it does fill, it won't stay full for any length of time (sadly curtailing my sailing season....).
ReplyDelete