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Anne Elk
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PostMon Sep 02, 2019 12:11 pm 
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Just read thru Cliff Mass's recent blog post, Is Western Washington Really in Severe Drought?  He goes on to explain why he considers the US Drought Monitor website calling our drought "severe" as hyperbole and shows some statistics to make his point.

I also read through the reader comments to this post and must agree with a number of his readers who have taken exception to this POV based on more inclusive metrics, ie, persistent soil dryness over extended periods of time despite the current rainfall patterns. The best counter-view was posted by this reader (emphasis mine):
Missing@Random wrote:
The drought index is primarily about growing conditions. That is soil moisture and vegetation conditions, not necessarily water resources (especially reservoirs). I agree that the subjective labels of the drought monitor seem to be poorly descriptive. That doesn't mean that conditions in western Washington are not unusually dry. As other commentators have pointed out: they are.

Perhaps there will be more support for this currently experiment index: the evaporative demand drought index. This index is a more quantitative way of measuring drought as the relationship between two variables: precipitation and water use of vegetative community. It also does away with "extreme" and "exceptional" descriptors.

The current index shows an anomaly for western Washington, especially southwest Washington: https://www.esrl.noaa.gov/psd/eddi/#current_conditions In short, we can take this mean that there is an evaporative deficit when compared to historical conditions. This isn't just a function of precipitation, as they point out in the user guide (https://www.esrl.noaa.gov/psd/eddi/pdf/EDDI_UserGuide_v1.0.pdf) drought can emerge even when precipitation is near-normal if evaporative demand is much higher than average. Evaporative demand is a function of temperature, humidity, wind speed and solar radiation aggregated overtime.

The index is unusually well documented, so kudos to the team that put this together. And there are probably things to quibble about (like the use of 0.5 m reference crop applied to what are primarily forest terrain).

Here's another:
Flying Bear wrote:
...my observation on South Whidbey that our forests are extremely dry, and are suffering from multiple dry growing seasons in a row. We're seeing increased mortality in all of the major, dominant tree species. Sure we've had some unexpected rain this month, which has helped and probably saved countless trees. The lower temperatures have also been helpful. However, this amount of rain has not made up the deficit.

Reservoir levels and stream flows are only part of the hydrologic picture. I'm interested in learning more about ground water levels during dry years, particularly the health of island aquifers like our water source on Whidbey.

And another, anonymous post:

Quote:
As a farmer I am struggling with persistently low soil moisture. My plants are dry dry dry, from roots to leaves, even with supplemental watering, even with a few days of rain. Leaves are dry and seem challenged by lack of moisture in the air too. Official drought or not, growing conditions have been much tougher than usual.

There may be some W Wa microclimate areas that are "greenish" but I believe most who are gardeners would agree the plants are stressed, including many natives. It also might explain the massive die-off of sword fern in Seward Park that's been reported in the media.  I've never been to Seward but would make a guess that it has less surface groundwater than some of the other city parks, e.g., Carkeek. The Seattle Times story said the scientists and volunteers are all looking for a pathogenic cause, and while there might be one, I think the underlying cause is stress from sustained soil dryness.  Slowly, the PNW seems to be turning into California.

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"There are yahoos out there.  Itís why we canít have nice things."  - Tom Mahood
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Jake Neiffer
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PostMon Sep 02, 2019 3:36 pm 
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A few thoughts.  This winter seem to vary widely from location to location.  This winters storms tracked south of central Washington of Washington for the most part.  I saw snotels at Lyman Lakes and others were extremely low in June.

Meanwhile we (35 miles south of the Columbia in Oregon) had snow later in the year here than we've ever seen.  A 90 year old farmer, sharp weather wise, said it was the most snow he'd ever seen.  He came out from North Dakota in 1949.  Wheat yields have been above average.  There was some left over snowdrifts in the Horse Heaven hills on I-82 south of the Tri Cities in mid-April.  Comically late in the year.  We enjoyed a small camp fire last night in the Umatilla NF forest- I don't recall fires being legal this time of year for a long time.

I personally feel the PNW is due for a drier climate, the west was settled in a historically wet period overall.

https://phys.org/news/2011-02-year-climate-longer-droughts-drier.html
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Cyclopath
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PostMon Sep 02, 2019 5:16 pm 
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The plants in my garden have been water stressed all summer ... despite watering.  The air has felt unusually dry this summer.  Some of the rivers I see often became small trickles earlier this year than normal.  We've had rain, but never torrential.

Cliff enjoys being a contrarian.  His writing about the mechanics of our weather are great, his opinion pieces seem like they're written for clicks.
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Anne Elk
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PostMon Sep 02, 2019 9:07 pm 
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I moved to the Puget Sound area in 1982.  My general impression of what's different now compared to my first decade or so here is that (1) summers are not only drier for longer, but also hotter. Fortunately we got a bit of temperature relief this year compared to the last three.  It was never a regular thing to have weeks on weeks of temps in the mid-80's and higher. (2) On average, we may still be getting the same amount of winter rain, but instead of it coming fairly evenly with many days of light drizzle, a lot of it comes in deluges, then weeks of mostly nothing. Various local microclimates may vary, e.g. in the Olympic rain shadow, and the Stillaguamish River valley is notorious for more rain than surrounding areas.

What I've observed in the gardens I help tend at Carkeek is that the soil gets so dry in the summer it becomes hydrophobic. That's a real thing.

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"There are yahoos out there.  Itís why we canít have nice things."  - Tom Mahood
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coldrain108
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PostTue Sep 03, 2019 6:25 am 
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When I moved back here in the summer of 1990 the news was making a HUGE stink that they were in the midst of an unprecedented 14 days in a row w/o precip. In July.  It then proceeded to rain.  I'm pretty sure 14 days doesn't even get noticed now.

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"The world will not be destroyed by those who do evil, but by those who watch and do nothing"  - Albert Einstein
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drm
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PostTue Sep 03, 2019 7:54 am 
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Cyclopath wrote:
Cliff enjoys being a contrarian.

That really is it.
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Anne Elk
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PostWed Sep 04, 2019 10:06 am 
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Cyclopath wrote:
The plants in my garden have been water stressed all summer ... despite watering.

I had some fun with this tool: Historical Palmer Drought Indices.  You can plug in any date range you want from 1900, and stop/start the map scrolling as you want to review month-by-month conditions. Although not super detailed, you can more or less  interpolate conditions for your local micro-climate. So far I've only tabulated 2015 thru current data (thru July) It was surprising how many months even the coast was in "severe drought" conditions by the Palmer metrics.

Anyone who gardens or pays attention to the conditions in the forests will appreciate the usefulness of the Palmer scale.  It's noteworthy that for this year, we've had 6 months of "severe drought" in the Puget Sound lowlands and 1 of "moderate drought". despite "all the rain" people have been perceiving. (August not added to data set yet.) By Palmer Scale methods, we're in worse shape this year than last year.

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"There are yahoos out there.  Itís why we canít have nice things."  - Tom Mahood
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Forum Index > Full Moon Saloon > Drought or no drought in W WA - depends on your metric?
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