Is A lot of Washington State Experiencing Extreme and Excessive Drought? • Watts Up With That?

From the Cliff Mass Weather Blog

Cliff Mass

It is very unfortunate when government entities provide information that is incorrect and exaggerated.

Misinformation made worse by the willing repetition by click-hungry media.

There are few better examples of the dissemination of exaggerated and inaccurate information than the drought claims of the U.S. Drought Monitor, the combined effort of several U.S. Federal agencies.

The latest Drought Monitor graphic for Washington shows SEVERE DROUGHT over much of western Washington and southeastern Washington (see below).

And EXTREME DROUGHT over the western slopes of central and northern Cascades and extending into Bellingham.

To put it politely, this graphic is silly and totally exaggerates the situation.  

To quote from the National Weather Service’s official drought webpage:
a drought is a period of unusually persistent dry weather that persists long enough to cause serious problems such as crop damage and/or water supply shortages.

An EXTREME DROUGHT would be expected to have devastating impacts.

The current situation is very different.  A drier than normal past year for sure, but plenty of water for nearly all needs.   Few impacts.  Plenty of water for human consumption.

Let’s explore the current situation with real data.  The current streamflow is shown below.  Most locations observe near-normal streamflow,  including in the “Extreme Drought” area along the western slopes of the Cascades.  As many above-normal streamflows as below.   Looks pretty normal to me!

What about water supply?  Is there a lack of water in the reservoirs for our use?   Take a look at Chester Mores Lake, the main water reservoir for Seattle, over the past year.  The levels are down from earlier in the summer, but similar or higher than last year in early fall.   Plenty of water for human consumption.

None of the major cities in the region have any problem with sufficient water supplies for its population.  For example, Tacoma’s supply is green (ample):

Tacoma Washington Water Supply

Everett’s water supply outlook indicates sufficient water:

What about agriculture?  With all the drought going around you would expect poor crops.

But that is not what happened.   

The apple crop, the biggest of our state, is way up:

The grape crop?  It was knocked back by a cool, wet spring (no drought) and the expectations are for smaller crop (down perhaps 20%), but the warm/dry summer (perfect growing conditions) is expected to produce an excellent vintage for many varietals.

The Water Year Precipitation

To get a better idea of how serious the current water situation is, let’s take a look at the historical rainfall.  The water year runs from October 1 to October 1 and is perfect for examining the situation today.

Here is the plot of water year rainfall at Olympia going back to the 1940s.  A green line smooths out the year-to-year variability.  This year is on the low side, but certainly, many years have been lower.  Little long-term trend is apparent.

Yakima had a very close-to-normal year.

Spokane was near normal as well.

The historically driest location this year was Hoquiam, located on the very wet Washington coast.   Have not heard many complaints from folks in that region.

Finally, the precipitation at Seattle’s Tolt Reservoir was near normal historically.

Do these actual numbers suggest extreme drought?  Finally, what about snowpack?  The end-of-spring snowpack this year was well above normal, providing a huge amount of water for all uses!

The Bottom Line is that the last year was drier than normal in terms of total rainfall for several locations.  But it was well within normal variability and there was still plenty of water for human consumption and most agriculture.

To call the situation a severe or extreme drought is simply deceptive and wrong.  It is counterproductive in many ways and undercuts the confidence of citizens and local agencies.  The Drought Monitor graphic is done subjectively and is a real roadblock for rational decision-making.

Let me note that there is no basis for predictions of a dry fall.   September was much wetter than normal and forecasts call for bountiful precipitation (see forecast for the next two weeks from the European Center ensemble system).  Looks moist to me.    El Nino years CAN have wet falls.

Crying wolf has never been a good approach.

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