Forecast on Track…So Far

10:30am Sunday…

The forecast is still on track for a Trace-3″ across the lowest elevations of the Portland metro area by Monday morning, with almost all of that sticking AFTER 7pm tonight.  BUT, the chance for someone to get really dumped on far west metro or up north toward Longview seems to have increased from what I saw at midnight.  Here’s the latest snow accumulation forecast from HRRR model.  A pretty good representation of what I think is most likely to happen between now and the Monday AM commute:

hrrr_snow_portland_19

Notice the heavier totals west and north metro and far less south and east where we’ll stay as rain or rain/snow mix before a late evening switchover.

As expected the airmass over us has cooled off and many are seeing a rain/snow mix in the lowlands.  Here at 1,000′ I’ve had mainly snow the past 2 hours, but it was sticking better an hour ago and now I’m getting more rain than snow.  I do see the warmer air is moving in aloft in the SE metro area with the sticking snow level up around 4,000′ just SE of Estacada on Wanderer’s Peak.  Yet at 1,000′ in the Coast Range it’s snowing like crazy.  That’s the effect of a stationary front sitting over our region; warmer south and east and colder north and west.

We’ve now seen the last of the model runs before this event.  The last-minute “wrinkle” is that they are all slightly farther south with the surface low pressure that tracks through the region this evening.  The ECMWF decided to move the low much farther south and now brings it just south of PDX around 10pm.   This is what I mentioned in the posting yesterday evening that “could go wrong”.  In this case that opens up the possibility that some locations in the far west or north metro (Forest Grove, Banks, Vernonia, St. Helens, Woodland) could get totally dumped on with snow this evening.  The ECMWF itself shows that possibility, although a bit extreme…a foot+ snow out near the Coast Range and north:

ecmwf_totalsnow

The resolution of the model leads to some contouring issues here, but you get the idea…loads of snow possible far west and north metro.  We’ll see how this plays out, is it really going to be a “Trace-15” in the metro area?  That sounds familiar…but could happen.

Flooding may be in issue this afternoon/evening as well with the heavy rain sitting directly over the Portland metro area.  Assuming it all falls as rain south and east metro through the evening, check out the forecast from the HRRR!

hrrr_precip

That will cause some urban flooding and creeks surge out of their banks.  I’ll be keeping a close eye on that this afternoon too.

I’ll be doing some live Facebook videos later once I get settled in and the Super Bowl is on, then we’ll be on the air much of the time from 8:30-11pm tonight on FOX12.

Chief Meteorologist Mark Nelsen

58 Responses to Forecast on Track…So Far

  1. Lee Wilson says:

    Loud Explosion Heard
    Grid down!
    In castle Rock Washington

  2. Lee Wilson says:

    Sory, I am not feeling..well…logged in with the wrong account.

  3. Marlene Bickar says:

    Good Afternoon Mark, Here up in North Kelso, we’re at an elevation of 27′ I just measured the top of our patio table, that’s where I get the most accurate measurement we have just at 11/2″ of SNOW. and the SNOW just keeps coming. BEAUTIFUL. I don’t think Schools from Kalama, North will be going tomorrow.

  4. Jacqueline says:

    We live in Camas at 2000 ft elevation on Livingston Mountain. Been snowing since 7am this morning and already have about 6 inches so far!

    Loving this winter up in the hills!

  5. Diana F. says:

    For this particular RAIN / SNOW event, THIS is my absolute favorite tool to play with!

    https://www.wunderground.com/wundermap/?lat=45.64&lon=-122.68&radar=1

    • Dana says:

      Thanks for sharing this nifty resource, Diana. The resolution is pretty crisp!

    • Diana F. says:

      Glad you like it. Super fun to click “webcams” on the right, so you can instantly go anywhere in WA / OR and see the ACTUAL, at the moment weather, AND usually with a private webcam, as opposed to a traffic cam. Love this weather! Even though I’m just getting rain in NE Vancouver! It has been raining nonstop all through the night and all day too…..we have vaulted ceilings so rain hits the skylights with a ping ping ping….needless to say…..constant pinging!

  6. pappoose in scappoose says:

    33 degrees
    1″ on driveway
    snowing hard

    Scappoose DEQ Clean Air Station

    http://www.deq.state.or.us/vip_sc_cam/readImage.asp

  7. SnowManiac says:

    Hey Mark. So what are your thoughts on the Tigard/ Bull Mountain area?

  8. ron says:

    Heavy sticking snow in Astoria—everything is covered. Bad news, however, is that the temp is still 35 degrees. I’d love to have it drop another three degrees!

  9. Aspiring Windowlicker says:

    Meanwhile, here in Salem, it’s nothing but nonstop rain. 41 with dp of 39.

  10. boydo3 N Albany says:

    South wind is beginning to take over from S to N. Mary’s peak went from freezing to 37 in the last couple hours with S winds up to 67 mph. Springfield has jumped to 60 deg.
    If this creeps north, the snow storm potential is over.

  11. Longview 400 ft says:

    Currently 33.3
    1/2 +
    Snowing hard

  12. JERAT416 says:

    75% snow as of 12:45 around Glencoe High School, but up here on Bull MTN. at 650ft, just all rain. Could it be just the pockets of showers or the north and south barrier making all the difference? Elevation makes no difference as of yet.

  13. Jane - Forest Grove says:

    Over 1″+ here, sticking to grass, cars and roads.

  14. Marie - Banks area 400ft says:

    Temp dropped from 37 to 35 since 11:30 and the snow is starting to accumulate for real now. And so it begins…

  15. Woodstock started with rain/snow mix this morning, it’s all rain now. Looks to be staying around 37F out there.

  16. Smokeycat says:

    What about North Clark County? Please mention us! Are we (Battle Ground) considered “North Metro”? All rain here at 1:00; about 350 ft. elevation.

  17. Anonymous says:

    This sucks. 43 degrees and all rain in Aumsville 10 miles SE of Salem

  18. peteramcg says:

    Skyline Blvd a few ticks north of Germantown..Steady snow since about 11 am. Big heavy flakes. About an inch already at 12:35pm. In the past few weeks we’ve lost a cherry tree, an old old Walnut Tree and an entire 30 ft Arbor Vitae. Yesterday was about our 180th power outage since I moved up here in 1994. This morning we still had traces of the last 20″ of snow we had here in the ditches next to Skyline. They’re all covered up now with new fresh clean show. We’re watching Groundhog Day while the power is still on. It somehow seems appropriate!

  19. Straight up heavy snow in Scappoose just off Hwy 30 for the last hour. Unpaved areas are all white.

  20. Sam Harris says:

    Been snowing here in SE Auburn since 8am this morning. Slushy white on the grass but snow has picked up in the last 45min. back to moderate. Sitting at 33 so hoping cold air aloft continues to move in during the day. Radar looks to be filling in nicely from the SW. Will be a fun day to watch football and snow!!!

  21. Deer Is. at 750' says:

    A solid 2″ here new. Been snowing since 8:30. Pictures in the comments on Marks Facebook page.

  22. Anonymous says:

    Been snowing here in SE Auburn since 8am this morning. Slushy white on the grass but snow has picked up in the last 45min. back to moderate. Sitting at 33 so hoping cold air aloft continues to move in during the day. Radar looks to be filling in nicely from the SW. Will be a fun day to watch football and snow!!!

  23. Anonymous says:

    How about beaverton area?

  24. Joshua Downtown PDX says:

    Temperature up a degree in less than an hour. Not good.

    • Scooter says:

      How can it be good or bad, it’s just a measure of the average kinetic energy of the particles in a sample of matter, expressed in terms of units or degrees designated on a standard scale.

    • Paul D says:

      Been staying around 38 in Hillsboro for two hours now. Boring!

  25. Marlene Bickar says:

    Hey Mark, up here in North Kelso at 27 feet elevation, we’re now seeing WET SNOW at 11:55 A.M.

  26. Longview 400 ft says:

    Currently 34.3
    Snowing hard
    Yard is turning white

    • Phil - St. Helens says:

      Rain/snow mix turning to all snow in old town St. Helens. Just starting to stick to the deck.

  27. Redland450' says:

    Only rain here and 38 degrees. Bummer.

  28. Boring 550' says:

    It’s been above freezing at Government Camp for a couple hours now.

  29. Joshua Downtown PDX says:

    Snow mixing in with rain here for the first time today. 36.5.

  30. Wendy-Silverlake, WA says:

    If it was 2 degrees colder we’d have several inches on the ground, but nope, it’ switching between 34 and 35 degrees. Been snowing since around 8:00 this morning, but nothing is sticking.

  31. Anonymous says:

    It’s been snowing since 6:30 or so this morning around Home Valley, WA in the gorge. Temp hovering at 33. Very wet snow, heavy at times and even when it lightens up it’s all snow not a mix.

  32. Destiny says:

    No chance of snow in Albany huh? 😦

  33. Dave in SW PDX (235') says:

    Temp has dropped to 37.0° here and the chunky rain has arrived. DP 35°. Just topped 1″ for my daily rain total so far.

  34. 12z euro run was too far S. Even 12z gfs a touch too far S. Based on radar trends and evolving projections of precip plume on the recent HRRR runs.

  35. Light rain here but many hilltop locations (such as SeaTac) now reporting wet snow. Encouraging sign that the changeover is starting to happen before noon. But… dome.

  36. Margie Grosse says:

    Snowing and grass is now almost white in Gales Creek ❄❄❄❄

  37. West Linn 500' says:

    All liquid rain, so far – Steady, not torrential but medium-heavy.

  38. Paul D says:

    Snowpocalypse is back!

  39. Alohabb says:

    So with the updates how does that pan out for the aloha Hillsboro areA? More than 4″. Possible 6″+?

  40. Scooter says:

    The ground here is fully saturated and now the runoff into the Clackamas River has started. In many events in the past years this when the rivers really start to rise as all the small streams and rivulets start dumping into the rivers.

  41. GTS1K' says:

    Heavy, wet snow last 20 min. – 33.5

  42. EY (Oak Grove) says:

    A tiny bit further south and east PLEASE

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