First Snow in The Passes This Week

7:30pm Tuesday

After 5 months of warmer than normal temperatures the month of October has been much different.  We are only 10 days into the month and we’re running well below normal.  In fact with the clouds and rain arriving just after midday, we ended up 7 degrees below average for the date.  A cold front is passing through the region right now, the leading edge of a much cooler airmass.  This begins a 3 day period of showers in the valleys.  Of course just like last month we’ll likely see a few thundershowers at times along with hail too.  But this time the airmass is colder which equals lots of Cascade snow!  That’s one reason I quickly finished up work in my garden the last two days, planted garlic, shallots, & cover crop.  I think we’re done with the warm season!

Take a look at the ECMWF model forecast of snow level over the next 6 days

The snow level (lowest elevation we expect snow to stick) should linger around 4,000′ through Friday night, then quickly rise well above all ski areas Saturday through at least next Monday.  With several disturbances giving us waves of showers, the snow is going to be piling up relatively deep up around 5,000′ and above.  Here’s our forecast for snow totals plus Cascade driving conditions

Yep, I think we could see up to 2 feet of snow at Timberline, and possibly up around 10″ or so down at Government Camp…that’s spread over the next 3 days.  Of course in October snow levels go up and down so most or all of that will melt this weekend and early next week.  But this should be the earliest measurable snow at Govy we’ve seen since October 2009; quite a change after the past few years

There will also be some snow (just a bit) over some parts of the High Desert of central and eastern Oregon…most likely Thursday and/or Friday.  Plus the first snow of the season could fall in the Wallowa Valley…winter is getting closer

Looking farther ahead, a strong “zonal” flow sets up Sunday through much of next week.  That means a Pacific jet stream will consolidated and flow mainly west to east, instead of this north/northwest flow bringing us the chilly showers right now.  Now typically that’s a very wet pattern for us in Fall.  But in this case Sunday and Monday the jet will be to our north, then sag south over us Tuesday through the rest of next week.  The result is a nice dry spell centered right over this weekend…good timing.  Note the ECMWF ensemble 24 hour precip forecast for the next 10 days:

You see not a single ensemble member has rain over us during that period, but they all are quite wet NEXT Wednesday-Friday.  Pretty good agreement the middle/end of next week will be a soaker.

To summarize

  • The next 3 days will be cool & showery in the lowlands and snowy above 4,000′ in the mountains
  • Cascade passes will be snowy at times the next 3 days, although only the summits will be icy since the snow level doesn’t go much below the passes….you’ll run into snow only near the summits
  • Saturday through Monday = dry, with varying amounts of morning fog to afternoon sunshine each day
  • Tuesday & beyond next week = back to wet weather

Enjoy the showers…everything is back to normal in the Pacific Northwest!

Chief Meteorologist Mark Nelsen



24 Responses to First Snow in The Passes This Week

  1. Boydo3 N. Albany says:

    The grass is still green in Fairbanks..

  2. Jason Hougak says:

    Very exciting weather day in the PNW indeed! Nice thunderstorm rolling across right now, heavy snow in the mountains, sun breaks, and even a tornado which hopefully didn’t cause any injuries. Hopefully just a sign of things to come for winter 17-18!

  3. j2m says:

    The National Weather Service in Portland has issued a

    Tornado Warning for…
    west central Clackamas County in northwestern Oregon…
    until 415 PM PDT.
    At 345 PM PDT, a confirmed tornado was located over Canby, or 7
    miles southwest of Oregon City, moving east at 20 mph.

    Hazard… damaging tornado.

    Source… public report of a tornado.

    Impact… flying debris will be dangerous to those caught without
    shelter. Mobile homes will be damaged or destroyed.
    Damage to roofs, windows, and vehicles will occur. Tree
    damage is likely.
    This tornadic thunderstorm will remain over mainly rural areas of
    west central Clackamas County, including the following locations:

  4. Roland Derksen says:

    We’ve been having quite the soaker here today; about 0.90 inches in the gauge from steady rain that ended shortly before 2:45 pm. Since then a nice break to sunshine, but it looks like the clouds are closing in again now.

  5. W7ENK says:

    Severe thunderstorm, Clark County.

    “… capable of producing a funnel cloud.”

  6. High Desert Mat says:

    Winter weather meeting bound!!!!!! Mark, get the prizes ready.

  7. Jason Hougak says:

    La Niña looks to be setting up strong with possible -4C temps toward end of month.

  8. Jason Hougak says:

    Radar showing steady precipitation which has snowlevel below base of Ski Bowl right now. Pass cams showing heavy snowfall.

  9. Jason Hougak says:

    Bought some fat skis on eBay for a great buy and ready for some powder turns! Was up on the north side of Hood last weekend and enjoyed a 4″ dumping of snow Saturday night with a spectacular morning sunrise.

  10. longviewer says:

    Like Benjamin I also like that first graphic, very clear and concise. Just finished cutting up most of the deadwood from last winter, not quite ready for more but it happens..

  11. Roland Derksen says:

    We need a lot more rain here in the next few days. So far with a third of the month gone, I’ve had less than a quarter of an inch in total. Maybe next week is going to make up for the shortfall somewhat.

    • Joshua Downtown PDX says:

      You’re likely going to get hammered next week. All of our systems have underperformed this month as well. Disappointing. Tomorrow should be pretty juicy down here. Late next week too.

    • Same here. We’ve had showers but no heavy soaking rains here yet.

      Went looking for mushrooms at Tahuya State Forest, which is typically wetter than where I live, and it was actually drier! The showers must have mostly missed there. Didn’t find any mushrooms, either. Too dry.

  12. Nahtalkin says:

    I really like Norma!

    • Paul D says:

      Me too! Just wish we could have a normal summer instead of all the heat we just endured. Maybe next year….

  13. Benjamin (West Salem) says:

    Thanks Mark for the nice update!! I like the chart showing the snow level. That’s a good way to communicate the actual snow level.

  14. But I hate normal weather Mark! We need to start wishcasting for a late October “wannabe arctic” cold snap, with a -8c airmass in the Columbia Basin and winter-like east wind in the Gorge.

  15. Boring 550' says:

    Looks like by the end of the month temperatures go well above normal. Maybe eek out another 70?

  16. Mark bergal says:

    I like normal too. Puts me at ease. Bring on the chill, rain, snow, wind, etc

  17. pappoose in scappoose says:

    Bring on the snow/hail/thundershowers/rain.
    I really like normal!

  18. Steve Miller says:

    All around perfect forecast!

    Hopefully we are done with warm weather until July 5th 2018…..nine months of cool and showery weather will be just fine.

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