As many suspected, with the rapid collapse of El Nino and the progression into spring, the weather patterns have shifted, opening the door to far wetter weather over the Northwest.
During the next 10 days, expect lots of precipitation, cool to seasonal temperatures, and even a good dump of snow in the mountains.
The official NOAA 6-10 day forecasts say it all (see below), with wetter than normal conditions and colder than normal temperatures over our region.
A vigorous weather system is arriving tomorrow, bringing a wet day. The total precipitation through Friday morning at 5 AM is shown below. A nice wetting for the entire region with some western slopes getting 2-3 inches. That is a lot for late April.
But this is just the beginning, with multiple wet systems arriving over the next week. The total accumulation through next Saturday morning (4 May) is impressive, with large areas of more than 3 inches. Keep in mind you need to multiply that by roughly ten to get snowfall in the mountains.
Over the higher elevations, the temperatures will be cold enough for snow, with substantial accumulations through May 4th. Some mountain locations will get several feet of new snow.
I suspect the snowpack will increase to around 80% of normal over Washington State and more than 100% of normal over much of Oregon within roughly 10 days.
The latest NOAA River Forecast Center forecasts for 10 days out are for near-normal river levels. For example, consider the Snoqualmie River (below). Below normal now, but near normal in a few days...and staying that way.
This and subsequent wet periods are well-timed to ensure sufficient water levels this summer.
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