If society and an informed electorate are going to make good decisions about environmental matters, they require accurate information.
Unfortunately, there has been a lot of poor information about climate change, extreme weather, and drought being distributed by certain government agencies and some media.
One example is the nearly constant talk about drought here in the Northwest and the western U.S. in general, often with a suggestion of a climate change origin.
The most problematic source of the drought claims is the U.S. Drought Monitor graphic produced by a collection of governmental agencies. This is a subjective graphic, with no rigorous methodology based on objective information. And it exaggerates drought.
Consider the latest drought monitor graphic for Washington State (see below). Much of the central and north Cascades are in "Moderate Drought." Whatcom County and Bellingham, plus Port Angeles to Sequim, are in moderate drought as well. The NE corner of Washington is in "Severe Drought." And large additional areas are claimed to be "Abnormally Dry"
Before we go further, how is a drought defined anyway?
Precipitation has substantial variability over time, with as many years above normal as below normal. How dry does it have to be to considered drought conditions?
The National Weather Service definition requires not only a deficiency of moisture but "adverse impacts" over a "sizeable area."
In short, drought requires serious societal impacts. So have we been unusually dry lately? Have there been impacts? Let's not be vague here.... we need to look at hard numbers and real impacts.
Let's start by looking at the cumulative precipitation starting October 1--the beginning of the water year.
For Seattle, precipitation has been above normal (green is actual, brown is normal)
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The plot from the official Seattle Public Utilities website suggests close to normal water storage (the red line is this year and the blue line is the long-term average)
So how could snowpack be below normal while precipitation is near normal?
A potential answer: it has been warmer than normal....with the very strong El Nino being the probable cause. Below are the recent temperature deviations from normal. Above normal over much of the state during the past 60 days.
So what do the latest forecasts suggest for the next ten days? Below is the predicted cumulative precipitation for that period from the European Center model.
California gets hit hard (classic El Nino). Lots of precipitation over southwestern BC and decent rain along the Washington Coast. These amounts are below normal for the Washington Cascades.
I made comment on one of your last drought posts and wanted to thank you for the tone of this post. The NWS should have advisory statements describing the various data used in evaluation. I know they issue statements but they are rather vague. I am particularly interested in the more subjective model inputs (vegetation stress for instance) and how the NWS determines the score and how it is weighted.
ReplyDeleteThe most recent Seattle office drought statement (12/14 ) is here: https://www.weather.gov/media/sew/DGT/DGT_SEW_12142023.pdf and comes to many of these conclusions.
What about considering for last water year? As the drought monitor has a lot of western wa in drought last water year it seems reasonable to consider that as well. Annedotaly a lot trees I'm seeing out in the woods seem to be still recovering from the dry summer.
ReplyDeleteThe City of Ferndale, located several miles north of Bellingham, recently drilled a new public well. In order to "future-proof" the project to ensure adequate water for residents as the population continues to grow and shallower aquifers are increasingly depleted, the new well was drilled all the way down into a previously unknown aquifer/underground river more than 1000 feet below the surface.
ReplyDeleteIt seems likely that if local governments are concerned about water resources to the point where they approve the allocation of serious amounts of tax dollars with which to attack the problem, then that concern is valid and important.
https://whatcom-news.com/new-city-water-well-reveals-surprise-1000-feet-down_76570/
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DeleteIt's all about water and if they want to know they have to have enough water available to support them. Doesn't seem to me they were "worried". They were doing what any good city would do. Also, given this was an "experiment" I would say they had funding help, otherwise would not go with such depths. With the new aquifer though I wonder if they will revisit the Whatcom County decision or if EPA will re look at WRIA's... nope, big cities and big organizations will continue to control water rights. While I cannot get any to improve my property and create forage for animals. Big companies slowly buying up rights selling to water banks, and cities getting all the water they need.
DeleteYes- unlike the Rockies, for example, where winter precipitation is almost invariably in the form of snow (and I lived in Gunnison, CO during my college years, so I have first-hand experience), we have a very marginal climate here for snowpack as it relates to reservoir capacity (and skiing!) and the percentage of the precipitation that falls as snow varies widely at the 3000-4000 foot level. The watersheds above our reservoirs are not particularly high- a large part of the terrain is below 5000 feet. Hence, in a warm winter, we must at times spill much water, and we depend heavily on reservoir capacity to last through the summer, whereas, in a cold year, the snow greatly increases the effective water storage capacity.
ReplyDeleteIf we obtained our water from glacier-fed reservoirs (such as Ross Lake, for example) our summer water supply would be less vulnerable to winter temperature fluctuation.
I would suggest that the gold standard for drought is the Palmer Index.
ReplyDeletehttps://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif
Isn't that going in the wrong direction from what Cliff is saying? At least it's clear that it is long term and changes slowly, and that it's about wet/dry. Curious why the Northern Rockies region is blank.
DeleteAn important item that you left out of your analysis is the water held by Glaciers. This may not be as big of an impact here but it certainly is in places such as the areas downstream of the Himalayas.
ReplyDeleteGlacier melt represents a very small source of water for the region. I can't speak for the Himalayas.
DeleteI was a bit confused about one part. You said "the Seattle SPS narrative suggests the reservoirs are a bit above normal" but then showed where they say the Tolt is "10.1 feet below its long-term average." Was that an error, or am I just missing something?
ReplyDeleteAlso I always thought the term "drought" referred to a long-term trend and the status wouldn't change just based on a snapshot of current conditions. River levels rise and fall substantially during any year, based on weather events. The Skykomish gets really low every summer, but that's not an indicator of drought, just like flooding from a strong storm doesn't mean the end of a drought.
Just hoping for some extra insight. I'm not an expert, but a lot of what I'm reading here goes against everything my dad, a hydrogeologist, taught me about drought when I was growing up in California in the 70s.
Once again, the AGW "The Sky is Falling!" crowd has shifted into the water panic - mongering meme, since the others they've been pushing are failing with the public:
ReplyDeletehttps://www.weforum.org/agenda/2023/03/global-freshwater-demand-will-exceed-supply-40-by-2030-experts-warn/
The WEF forum is about as objective as Pravda - of course snowpack is a concern, but we've been through this innumerable times in the past, and somehow we'll manage this current El Nino cycle.
Meanwhile, new aquifers being found...this is a ploy to take away what little rights we have to get water for ourselves away. They want full control.
DeleteMost of us will agree that there is a need for climate change action and that the average voter is apathetic at best. We also believe in "tell don't sell". Oddly enough local media profits from sounding alarms that promote our goal while distorting data. In this imperfect world I call that a win.
ReplyDeleteLet's take your assumption that "most of us will agree that there is a need for climate change action," at face value (which I don't). What is your solution? Additionally, please be specific in your list of actions that should be implemented.
DeleteWho is that that "most of us" that you speak for? Among the intellectual elite it's fashionable to consider truth and integrity to be sacrificial for the cause, believe in accountability to no one, and believe that de facto corruption doesn't equal corruption if it's in service of the cause. This isn't a new disease, just embraced by a different faction than in past history.
DeleteWas mountain biking lower valley singletrack in the BC interior Christmas Eve and Christmas Day. No snow at the valley bottom or half way up the mountains throughout the Thompson Okanagan, Boundary, Shuswap. Seems to be precip on the coast for rain, but a persistent ridge of high pressure in the prairies isn't letting anything inland.
ReplyDeleteThis is alpine snow pack; currently the lowest since the resort opened in 07/08 ... https://www.revelstokemountainresort.com/mountain/conditions/historical-snowfall-tracker/
One may think on par with last year, but last year was very cold so we had a lot of snow at lower elevations; this year is grass.
Maybe we need a better approach that works for Washington State - or at least parts of the State. I read your blog enough to know that the drought indexes have been a chronic complaint. Is there a better approach? My understanding of the maps is that the method likely does not work in our mountain terrane, seems to miss the mark in the drier parts of eastern Washington where direct soil moisture is readily available and does not seem relevant to much of western Washington. This is an opportunity for UW and WSU.
ReplyDeleteThank you Cliff. Please put it in your pocket to do a post on the predictability of heat domes, like the one in '21. I see NOAA's seasonal outlooks, but they don't really address short-term extreme events. I'd like to know if there is a meteorological method to establish heat (wave, dome) probability, with some lead time. Thanks again.
ReplyDeleteThis confirms my suspicion that this drought product exaggerates drought conditions.
ReplyDeleteWhere's it all going? (The water, that is.) It doesn't just get used up, never to return. Relax. Have a creme soda.
ReplyDeleteWe reached 63 degrees in Mukilteo today. We went to the beach and my kids were happy in t-shirts. Were there records broken today? I can't remember ever seeing 60s this late in December.
ReplyDelete