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.