April 13, 2024

A Drier Than Normal Spring over the Pacific Northwest

I had to water some new plants today because the last few weeks have been relatively dry.   So I was curious.....how dry has it been in our region?

Below is the March 22-April 12th precipitation in Seattle for the past 75 years.  This year we had 1.5 inches over the period when 2.5 inches is more typical.  

Not a record dry year by any means, since some years had only about 0.3 inches for the same period.  Interestingly, early springs have gotten a bit wetter over the past 75 years, so one can't blame the dryness on global warming.


Another reason you can't blame global warming is that just down the coast, southern California is experiencing one of the wettest springs on record.   To demonstrate this, look at the March 22-April 12 total precipitation in Los Angeles for the same period (below).

A very wet year and much about normal.


To give you some spatial perspective,  below is the percentage of normal precipitation for the past month.

Much wetter than normal in southern California (blue and purple colors), but drier than normal over western Oregon and Washington. Very wet in Arizona.

This pattern, dry north and wet south, is associated with a persistent atmospheric pattern this winter and spring, with a strong trough of low pressure off California.  

The forecast upper level (500hPa pressure, about 18,000 ft) is shown for today at 5 PM---exactly what I was talking about.  A strong low parked over California.


For those hoping to save on their water bills, the forecast precipitation through Thursday morning is more of the same.  Wet California and a few light showers over western Washington and Oregon.

I am getting totally bored of this.






6 comments:

  1. Dry weather is great for removing the rocks of my new lawn site, a 1/4-acre in size. The dirt is dry and doesn't clump, so I can sift the soil from the rocks, and dump the rocks elsewhere. Then, I'll have a lawn-mower friendly patch of ground for the grass. Not so good for keeping the grass seed moist while it's sprouting. Trying to sprinkle the site won't work, it's too big.

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  2. I'm with you, Cliff. When you throw in the observation that Seattle is where convergence zones go to die (or at least to turn into something that should be put out of its misery), I'm just about ready to move up to Arlington.

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  3. Boring it may be, Cliff, but it sure was a nice weekend: I got in a 62 mile bike ride up to Arlington, and some gardening and running. If you want exciting weather, go to the Southeast- as you know, they get lots if it!

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  4. Did you see this? https://ecology.wa.gov/about-us/who-we-are/news/2024-news-stories/april-16-drought-declaration

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  5. Yes- Cliff said we are not in a drought but the alarmist types insist we are. Apparently they don't have enough bad news to satisfy their craving for it. You are not going to get 100% of average snowpack every year. You might say that most years are going to be significantly above or below average. I do wish "they" would shut up sometimes.

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  6. I'm from northern California...where a Real drought occurred for 30 years. Our Governor just declared a state of emergency because of a drought. Serious? There were a couple times this year I thought I would have to build an ark because our house was going to float away.

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