Monday, September 28, 2020

a wet week

 The past seven days provided us with about 3½ inches of rain, so September has again beat the 30-year average by quite a bit. Sep/Oct have been the most consistently wet months since we arrived here, a definite change from my memories of Septembers in Portland. Amazing what an hour's drive (or a 30-minute crow flight) can do to conditions, with the Columbia gorge reduced in influence. The 'water year' shown here begins in July, so the long-time averages are 189% for September and 180% for October. September has doubled its average here three times, but the wettest-ever month was October 2016 at 366% - over twenty inches.



Note that August, November and May are the least efficient months on our hill-top, with fairly consistent underperformance relative to the 1981-2010 period. November is supposed to be our wettest month of the twelve, with 10.84" expected; it's reached that twice but failed badly twice; last year left a hole that needed a huge January managed to fill (over 18" total, second-wettest month on the list!). 

Averages are one thing, standard deviations quite another!




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