PORTLAND, Ore. (KOIN) – We are just one day away from the water year, which runs from Oct. 1 to Sept. 30, wrapping up. With no rain in the forecast this week, we are sort of set in stone with our numbers.
That growing ridge of high pressure is going to keep Tuesday warm, sunny, and a bit breezy, meaning there will most definitely not be any rain. Where is the closest moisture? It’s going to be well to the west or east for the remainder of the week, with breezy and wet conditions around the Gulf of Alaska and that system to the south of the Aleutian Islands by Wednesday.
Now there are a lot of numbers with this weather blog, so for those of you who like stats, this is a weather blog for you!
With that, why don’t we take a look at how the water year shaped out. We are going to finish at 27.98 inches here in Portland. The water year normal, according to the National Weather Service in Portland, is 36.03 inches. That will put us at a departure of -8.05 inches for the water year.
It isn’t hard to believe when you see the chart below. Only three months of the water year did we come up above average. We weren’t exactly even close to the average for most months, with the exception of May. Most months fell short by a landslide.
Where it was the most alarming, was in November, when we barely topped 1.5 inches. November is our wettest month on average, we should be up in the 5.5 inches range for the month. We then followed up with a below-average December. January tried to make up for the deficit but we were already pretty far behind. Late winter and spring remained dry. If it wasn’t for a few thunderstorms and a couple of rain events in June, we would have really been hurting by the summer.
This was the driest water year since 2008-2009, where the total came out to 28.00 inches flat. With only 27.98 inches this water year, we have gone three years in a row below our water year normal. That was following two wet water years in 2015-2016 and 2016-2017. The driest on record comes in at 22.99 inches in 2000-2001 and the wettest, you can guess it, is 58.67 inches back during the water year of 1996-1997. I would like to note that the average for 2010-2019 came out to 38.81 inches.
Below are a few graphics from the Northwest River Forecast Center with NOAA. You can see the “Seasonal Precipitation” on the left, which is the water year up to Sept. 27, 2020. The graphic on the right is our current September month as far as the monthly precipitation percent of normal. Many locations west of the Cascades are sitting around 70-90%, with a handful below in the orange and red. There are some areas that hit around normal or above. That should be stated too. As far as our current month goes? September is going to finish above because of those back to back atmospheric rivers. They sure didn’t leave much moisture for the rest of the state.
Until the next water year!
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