Wet Season Arriving

6pm Thursday…

When I think of typical October weather, today would pretty much cover it.  Not a real soaker, but gray and rainy at times.  We’ve picked up about a quarter-inch of rain so far in much of the metro area:

Rain Metro Today Databound

I’ve been expecting a decent amount of rain during the next week, but models are a bit wetter today.  Check out the 7 Day precipitation forecast from the ECMWF, that’s through next Thursday

ECMWF Precipitation Accumulation

Pretty wet!  If this occurs, October will go down as a wet one even though we had two weeks of sunshine in the middle of the month.  This points out how things can change quickly in late October as the wet season arrives.  Notice a few spots in the Coast and Cascade ranges with 6-8″ of rain; this will provide the final soaking to finish off what was left of this fire season.

Sunday could be a particularly active weather day with frequent showers, downpours, and thunder/hail.  It’s a cool and unstable airmass moving overhead that day.  By Monday morning we’re back to that chilly airmass we saw in early October; expect snow down below Timberline Lodge but not quite sticking to the passes.  You see the dip in snow level here:

ECMWF Snow Level From 850mb Temps LONG TERM

By the middle of next week strong high pressure offshore will somewhat shut down the rainfall, or at least slow it to a trickle as we enter November.  One weak system will slide over the ridge on Halloween and that COULD give us a rare wet Halloween evening, we’ll see.  Most of the past 15 years we’ve seen dry conditions during that critical Trick-or-Treat time 5-8pm.

Halloween Weather History

Looking farther ahead, the weather pattern still looks mild and slow later next week and that first weekend of November.  You see the upper-level ridging and mild conditions on the ECMWF ensemble 500mb heights on Saturday the 3rd


There are hints of a cooler pattern just beyond that, maybe 12-14 days from now.  We’ll see, that’s a long way off.  For now I’m still confident that we don’t see a stormy pattern through the first week of November.

Chief Meteorologist Mark Nelsen

6 Responses to Wet Season Arriving

  1. W7ENK says:

    Closed out yesterday with 0.46″ in my rain gauge.

    Another 0.04″ overnight.

  2. Ken in Wood Village says:

    Thank you for the update Mark. I think this year will be full of surprises. I’m guessing we won’t know if it will rain a lot or just sprinkle until it’s 3 to 4 days out. Like this storm, everyone thought most of the action was going to happen North of the Columbia River but instead we finally got some good rain. We’ll see about next week Mark. First 🙂

    • Paul D says:

      First reply!

      • Ken in Wood Village says:

        LOL, third reply…hehe 🙂

        • K says:

          Technically, yours is the second reply. (lol)

          Anyways, Sunday’s storm looks like the first juicy one of our season. I’m looking forward to it!

        • Ken in Wood Village says:

          Hehe, after I clicked Post Comment I said to myself, “That would be second” lol. Wish it was like Facebook were you could edit it…lol. Yea, Sunday looks like a good storm (finally) after not having anything for a long time. Hopefully we get some good thunderstorms 🙂

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