The complaints are coming in.
I can't tell you how many people have told me that this spring is unusually bad. My son, a Northwest native, is threatening to move to southern California because of the weather.
Green slime is spreading on my deck.
So have we really been cooler and wetter than normal? How bad is it really?
Ok, let's check the facts.
We can start by look at the difference from normal of the average temperatures over Washington State for roughly the last month. Most of the Washington State is green, blue, or purple--the colors indicating below normal temperatures. The above normal temperatures at Yakima I would ignore, there is something wrong with thesensor. Slightly warmer than normal east of the Olympics.
So yes, the state has been a few degrees below normal. Looking at Seattle's temperatures for the last four weeks (red lines), compared to the normal highs and lows (purple and cyan lines), we can see that things weren't that unusual, with temperatures rising above and below normal.
Yakima temperatures look pretty normal to me.
Spokane does appear to be significantly below normal for the past month.Bottom line:
the complainers probably have a point about it being cooler than normal, something that is typical of springs during La Nina years. But around Seattle, just a little below normal.What about precipitation?
A much more complex story. Here is the difference of observed precipitation from normal for approximately the last four weeks. Wetter than normal along the western slopes of the Cascades and much of eastern Washington, but way drier than normal to the east of the Olympics and in locations just to the east of the Cascade crest.
I bet I know what is going on.
During the last month we had an unusual number of days with westerly winds (from the west), which resulted in a strong rain shadow to the lee (east) of the Olympics as the air descends down towards Puget Sound. And persistent westerly flow explains the heavier rain on the windward (west facing) side of the Cascades.
Here is the cumulative precipitation at Sea-Tac compared to normal for the past month... the observed (purple) was a bit more than normal (cyan).
Yakima and Spokane? Considerably more than normal, at least percentage wise (they don't get that much there).
What you really want to know is the future, right? Well, there is plenty of cool, showery weather through the weekend.The next week will make ducks very, very happy.
Here is the forecast accumulated precipitation through next Thursday at 5 PM. Large amounts (5-10 inches in the Olympics and Cascades) and even substantial precipitation down into California. And freezing levels will be low enough for substantial snow from BC to the Sierra Nevada.
I think I will see if my son can get a ticket for California for me as well.