April 1 Special: The Initiation of UW ClimateLab Reports

 Concluding that if you can't beat them, join them, today I will start the first in a series of UW ClimateLab examinations on the effects of global warming on our region.

In this issue, let's examine the effects of global warming on spring (March-May) conditions in the Northwest by looking at trends from 1950-2024.

In western Washington, Olympia Airport is a good place to start, since there is less urbanization than central Puget Sound (see satellite image for the surroundings, below)

Starting with the annual highest spring temperatures (below), there is nearly no long-term trend (brown line).   Very surprising......and disappointing for those who enjoy warmth in spring.

In contrast, there is modest warming for the average springtime high--by about 2°F since 1950.

The mean minimum temperature has warmed up by about the same amount (2°F)

Precipitation at Olympia? Up about an inch.

ClimateLab conclusions:  No increase in extreme highs.  A little moister.  A Modest 2F increase in average highs and lows.

Now let's turn to Eastern Washington...and you can't go wrong with Ephrata, which is hardly in an urban neighborhood.

For the highest spring temperature, there has been no upward trend.  Nada.

The mean daily high temperature has increased slowly, by about 2.5°F since 1950

And surprisingly, the mean minimum temperature has cooled.

Spring precipitation has increased slightly.

Bottom line:  very similar to Olympia, with precipitation increasing slightly, the extreme temperatures remaining the same, and the average high going up about 2°F.

Virtually all stations in Washington State without urbanization or other issues are similar.  

Extreme springtime highs are not going anywhere, and precipitation is modest.  Average highs have gone up about 2°F in 75 years, without acceleration of the warming.

The ClimateLab will allow you to decide whether this is an existential threat or a crisis.

Happy April 1.

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Important Notice:  My UW talk will be delayed until April 17.

April 1 Water Status

On April 1, water managers and others often appraise the water situation as the wet season ends and the dry West Coast dry season approaches.

So a day early, let's get a look.

For the water year (since October 1), the Western U.S. has been a mixed bag, which is not unusual.  Eastern Washington, most of Oregon, and northern California were considerably wetter than normal (see percentage of normal precipitation below).  Western Washington and central California were modestly drier than normal, while southern California and Nevada were much drier than normal.

With most of the large reservoirs in northern CA and last year being wet statewide, most CA reservoirs are in very good shape with lots of water (see below).

Looking at river levels, which reflect precipitation during the past weeks, many rivers are running above normal in Washington, Oregon, and northern California, and near normal in most of the rest of California.  Good for fish.

Snowpack?   Well above normal in most of Oregon and northern CA, near normal in southern WA state, and modestly below normal over northern WA and central CA (see below).
 

Here in WA State, the westside reservoirs are near normal.  But the really good news is that the Yakima Basin storage, which was much below normal, appears to be rapidly recovering.

Bottom Line

I wish I could provide you with a dramatic story, but the wet reality of this winter is quite normal and typical, with some places being a bit wetter and drier than normal. 

Looking forward in time, the European Center seasonal prediction for March-May is wetter than normal over western British Columbia, Washington, Oregon, and northern California, with drier conditions over the Southwest (the map below shows the difference from normal).