Drought Exaggeration

One of the most misused terms is drought.    Certain groups and individuals are constantly using the "D" word when it is not appropriate, often to support their own agenda.

The most frequent source of the most exaggerated, unfounded drought claims is the Drought Monitor graphic, produced by a partnership between the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration (see the most recent graphic below).

The trouble is that these graphics are subjective and often wildly wrong.  

And they are virtually always wrong in the same direction: exaggerating the intensity of the "drought."

Want a good example?  Consider the LATEST Drought Monitor graphic for Washington State released on Thursday (see below).  It shows the conditions for last Tuesday morning

Moderate drought over western Washington, most of the Cascades, and the eastern slopes of the Cascades.  Severe drought over the western slopes of the central Washington Cascades, the eastern slopes of the Cascades, and northeast Washington.   EXTREME drought over southwest Washington.

Drought during a period of flooding, moist soils, and above-normal reservoir levels.

How can I put it diplomatically?   

This is inconsistent with reality.

Climate advocacy groups, such as the Seattle Times Climate Lab, take exaggerated drought claims like this as gospel, and hype is further. (see below)

So, When Should We Use the Term "drought"

Some groups, like the Drought Monitor folks at the University of Nebraska, call it a drought when rain or snow are simply below normal.

This makes little sense, since precipitation will be below normal half the time.  So 50% of the time we are in drought?   Silly.

And what about impacts?   A drought must produce serious problems due to a lack of water.

More scientifically grounded groups, such as NASA (below), use such a definition.

There is no way our region is in drought, by any rational definition.  

During this fall wet season, most locations received MORE precipitation than usual.  

To illustrate, here is the difference from normal over the past 60 days. Most of the state was above normal, with large areas receiving MUCH more precipitation than normal (the North Cascades).

The biggest drought concern has been the Yakima Valley and its reservoirs, with the latter being significantly below normal at the end of the summer.

Now the Yakima reservoir levels are MUCH  higher above normal (see below).

Local rivers? Most are flowing much above normal (see below).

Westside reservoir storage?  All above normal (Seattle shown below).

The water level in Lake Roosevelt, behind the crucial Grand Coulee Dam?  Above normal!

 

Soil moisture? Large areas are above normal (green colors)

The only aspect that is below normal right now is regional snowpack, but being low in mid-December is not unusual, and lots of snow is expected during the next week (and has been in the forecast for over a week).

As shown below, the snow situation for the Columbia Basin is excellent (well above normal), and the north Cascades is at 77% of normal.    The Yakima basin has about half of its normal snowpack.

A major enhancement of snowpack is now forecast, with huge amounts predicted for the Cascades during the next five days (see below). 

In short, there is no rational reason to suggest that Washington State is now or will not be in drought during the next months.      

And there's something else.

Washington State receives far more precipitation than it needs.  Thus, a modest dry period (such as last spring and summer) had relatively little impact on the economy or essential water resources.  You really should not use the term drought when impacts were not evident.

The Incoming System

 I wanted to provide a brief update on the incoming system.

A strong front is approaching, which will bring modest winds and substantial mountain precipitation...but nothing like we endured last week.

The latest forecast precipitation totals through 4 PM Monday is for "only" 3-5 inches in the Olympics and northern Cascades.

That will drive some of the local rivers up to moderate flow levels, but not nearly as high as last week.

Here is a sample for the Snoqualmie River,  where levels just reach major flood levels.  Also, a much lower peak this time.

Then there will be some winds associated with a strong cold front and the low pressure accompanying it. 

This forecast surface map for 7 AM Monday shows the  pressure pattern (solid lines), winds, and temperature (shading).  A strong front is offshore at this time, with a large north-south pressure difference over western Washington.  That means strong winds from the south.

By 4 PM, the front has moved in, and cooler air has swept into western WA.  A big pressure difference across the Cascades means strong winds descending into eastern WA.   Good for wind energy, bad for power outages around Ellensburg and Leavenworth.

Here in western WA, wind gusts should reach 40-50 mph, as illustrated by the Seattle WindWatch graphic for Seattle (below).

A few outages should be expected in western Washington--tens of thousands, but no more.

Finally, the big upcoming weather story will be SNOW.   Lots of it in the mountains, as illustrated by totals through next Sunday (below).