No Reason to Worry Yet About Summer Drought in the Northwest

The second half of March was very dry.  No doubt about it.

As a result, Washington snowpack has declined, ranging from roughly 60-90% of normal.

And a nervousness has spread in the media and among some politicians, some talking about summer drought, increased wildfire risk, and degraded agriculture.

My reading:  the current situation is NOT serious, that the snowpack is not that low, that our reservoirs are in good shape, and that substantial April rain/snow will ensure that we go into this summer in reasonable shape.

A sample is shown below, ranging from a drought emergency to predictions of smoke-filled skies and reduced irrigation water.

Now, let's look at the facts on the ground and consider the forecasts for the next week or so.    April plays a critical role regarding summer drought in the Northwest.   If April is dry, the summer desiccation season gets a head start,  leading to enhanced drying and a too rapid loss of snowpack.  But a wet April is a boon, keeping the area moist and the snowpack in place.

So where are we right now? 
The snowpack is fine along the southern portion of the state. OK, over NW Washington (low 80s%), decent over the Olympics (79%), but only around 65% on the western side of the north/central Cascades. 

Some media outlets are comparing this to 2015...but it is NOTHING like 2015, when the early April snowpack percentiles were in the single digits in some locations (see below).

Unlike 2015, April this year should bring more snow.  In fact, the National Weather Service is going for substantial amounts (up to a few feet) and they have winter weather advisory out right now.

The WRF model forecast for accumulated snowfall for the week shows several feet of snow in the Cascades, just where it is low now.  Expect the snowpack numbers to improve substantially.

And there will be plenty of total precipitation over the region during the same period, including eastern Washington.

Reservoirs?

Even before the recent precipitation, Seattle's reservoirs were just a bit below normal:

The critical Yakima system is modestly below normal to starting to move towards normal:

The bottom line is that this year is very typical for a weak to moderate El Nino year, with snowpack and precipitation a bit below normal, but nothing serious.

from Cliff Mass Weather and Climate Blog http://bit.ly/2uXs3Gf