9am: No Sticking Snow For Most Today

Good Morning!

As I mentioned yesterday, if we don’t get heavy enough precipitation to drag down the snow level, the snow level will stay higher today (read in previous post).  That’s exactly what has happened.  Only .10-.15″ precipitation for PDX, Vancouver, & Hillsboro.  In fact Troutdale has only seen a trace!  As a result we’re at the lower end of that ZERO-1″ I forecast in the lowest elevations.  It’s been a mix of rain/snow showers, and the cool atmosphere can’t overcome the breezy/mixing southerly wind we were expecting as well.

This has screwed up the hilltop snow forecast.  I expected 1-3″ up around 1,000′ and above.  The lack of heavy precipitation is putting us at the lower end of that for sure.  So far at 1,000′ at my home (east of Troutdale) I have just a dusting.

You may remember my rant about snow level forecasting in these showery patterns.  We’re doing people a disservice by implying we have more accuracy than we do (in this pattern).  This morning is a perfect example of why forecasters (and the NWS) shouldn’t be forecasting snow level in increments below 1,000′ in a snow shower pattern.  A snapshot at 8:30am:  Staley’s Jct. on U.S. 26 west of Banks…elevation 200 feet.  A snowy road and maybe a half inch on the ground:

us26-at-staleys-junction3_pid2985

At the SAME ELEVATION, but 15 miles east on the west side of Beaverton…all bare and wet with no snow in sight:

26bethany_pid524

Then over on the eastside of the metro area just above Sandy…at 1,200′.  NO SNOW. The white stuff is left over from yesterday’s hail/graupel showers.

us26-at-firwood-rd_pid2331

So what was the “snow level” at 9am???  Under the heavy showers it was near sea level, where very little precipitation fell it was higher, up around 1,500′.  There you go…rant over for now.

THE REST OF TODAY

  1. Snow showers or snow/rain showers continue.  Some maybe be heavy this afternoon with a rumble of thunder if we get some sunbreaks inbetween.  Hail or ice pellets are possible too.
  2. NO ACCUMULATION AT THE LOWEST ELEVATIONS…HIGHWAYS REMAIN TOTALLY CLEAR unless we get hail/ice pellets out of a heavy shower suddenly in just one location.  Evening commute should be fine.
  3. A Trace to 2″ is still possible at/above 1,000′…more the higher you go

TONIGHT

Snow showers continue, could be a dusting on the hills overnight, but nothing likely in the lowest elevations.  Assuming we stay mostly cloudy, I don’t think leftover wet roads freezing are a problem, but I’ll look at that more closely this afternoon.

Chief Meteorologist Mark Nelsen

 

 

 

49 Responses to 9am: No Sticking Snow For Most Today

  1. Welp, forecast has turned white for me again. Most likely I’ll get a dusting when the Fraser outfow hits, but if everything goes optimally up up 3″. Would be pretty to have some white on the ground while the Fraser outflow is going.

    Given how much flip-flopping there has been, all I can say at this point is that the odds favor me getting some more snow.

  2. Ryan (Walnut Grove) says:

    I suppose on a positive note the GFS operational continues to insist on a real Arctic outbreak middle of next week. Sometimes wanting to dump a boatload of snow; other times just dry and frigid.

    Of course, beyond 7 days and the Operational so take with the proper amount of salt.

  3. HAWKEYES23 says:

    One of the longest long term discussions I have ever seen

    Area Forecast Discussion
    National Weather Service Portland Oregon
    318 PM PST Mon Dec 5 2016

    .SHORT TERM…Tonight through Wednesday…A band, possibly a front, moved through southwest Washington and northwest Oregon late this morning and this afternoon and dropped snow levels to near the valley floors from the heavier precipitation rates much as expected. The NAM12 actually pegged this pretty well per model soundings such as for KPDX. Saw several pics of accumulating snow even at fairly low elevations. There is a surface low along the Washington coast this afternoon that will drop south along the Oregon coast tonight and continue to feed showers from the northeast Pacific into our area. Snow levels will definitely be dropping to the surface in most areas after sunset tonight. The snow showers will lead to some more accumulations in the coastal mountains, foothills and Cascades when generally some dusting at the valley floors though a local accumulation is possible. Have made some adjustments to the advisories to reflect these ideas.

    Drier northerly flow will spread in from the north on Tuesday as the
    surface low moves south with drying. A few showers may linger in Lane County until late in the day.

    An upper ridge will build in Tuesday night and Wednesday with strong offshore flow developing especially on Wednesday. The winds will be quite strong especially along the Columbia River and through the Portland and Vancouver metro areas. After some areas of morning valley freezing fog, the day will remain on the cold side in the afternoon with some wind chill affecting comfort. This will also set things up for the winter weather mix expected Wednesday night and Thursday that has been moved to the next section for this issuance. Tolleson

    .LONG TERM…Thursday through Monday…
    Precipitation will begin as snow for most areas Wednesday night with a few inches of accumulation expected before the transition to ice begins. Currently, have precipitation all rain along the immediate coast on
    Wednesday night, but given the strength of the offshore flow, it is
    possible that the column will remain cool enough for a quick round of snow even at the beaches. Will wait until the shorter term period with higher resolution models to better diagnose the possibility of coastal snow.

    The Thursday morning commute is looking quite treacherous as an atmospheric river event overruns the cold air in place over the
    area. Precipitation will change to freezing rain during the late
    morning to early afternoon. Don`t anticipate freezing rain sticking
    around too long for the south and central valley as winds switch
    southerly pretty quickly. Despite the short duration, a few tenths
    of an inch are possible on top of the inch or 2 of snow which will
    cause significant issues. The higher end impacts will be in the
    Columbia River Gorge and eastern Portland metro areas. This is where there is still a lot of uncertainty with regard to the duration of
    the freezing rain. Models have trended later into the day Thursday
    with the east winds continuing. It is hard to latch on to a specific
    solution at this time given the model uncertainty about the cyclogenesis offshore.

    The ECMWF ends the east winds through the Gorge quicker as it has a weak surface low which comes onshore near Astoria at 00Z Friday. This surface low coming on the coast will displace the Columbia Basin high pressure and end the supply of cold air. The GFS, GEM, and NAM all have a stronger surface low tracking somewhere towards the Vancouver Island/Olympic Peninsula area. This is the preferred solution at this time, especially since yesterday`s 12Z ECMWF showed a similar solution. Even though there are 3 models in agreement with a stronger surface low, the exact track of this system is still very important. The GEM and NAM track the surface low further northwest than the GFS. As a result, the high pressure in the Columbia basin would be able to sustain itself much longer without a low pressure center or strong front kicking it out. At this time, have kept the ongoing forecast more in line with the GFS for the Portland metro area which has snow through late morning followed by freezing rain through the afternoon and changing over to all rain sometime during the evening Thursday. Am not necessarily convinced the GFS is the
    correct one, however, this solution is a good compromise between the possible solutions at this time.

    It is worth mentioning that if the more pessimistic solutions
    verify, NAM or GEM, the Columbia River Gorge and even the eastern Portland metro could see a major ice storm. It is still a bit early to jump on that solution, but it is important to mention that possibility as agencies prepare for this winter event. Especially
    given the trend in the models towards longer duration east winds and the tendency for east winds in the Gorge to sustain longer than models forecast.

    While there is plenty of potential for frozen precipitation impacts,
    another impact which confidence is higher for is strong east winds
    through the Gorge Wednesday Night. The DLS to PDX gradient is modeled between 8 and 10 mb. Models tend to under forecast this
    pressure gradient by a few mb, therefore expect the gradient to top out over 10mb. This type of gradient would bring mid 40 mph wind gusts to the eastern Portland metro area with winds likely
    approaching 100 mph at Crown Point. As if these winds weren`t
    impactful enough, as ice begins to accumulate on branches and powerlines, impacts could quickly snowball. To reduce confusion with an ongoing event and winter weather advisories currently out, will not issue a high wind watch at this time. A high wind watch will likely be needed for at least the Gorge at some point given our fairly high confidence about the strong winds

    Beyond Thursday, the big story will be continuing snow in the
    Cascades. Several more feet of snow are likely between Thursday and Sunday as freezing levels stay below 3000 feet and fronts continue to move on shore into the weekend. Snow may even impact a few of the Coast Range passes as snow levels dip to near 1500 feet at times.

    Bentley
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    Comment

  4. marinersfan85 says:

    Gfs has backed off of anything frozen on Thursday morning.

    • runrain says:

      I hope we’re still going to get the strong east winds. I have a lot of leaves still on my trees that need to get blasted over to my neighbors lawn 🙂

  5. UW WRF-GFS has now completely backed off of any accumulating snow for me as the Fraser outflow hits tonight.

  6. Hal in Aims says:

    glad to see nothing has changed……2″ of snow and the power goes out………

  7. Anonymous says:

    It’s been snowing here in Oregon City for over 2 hours and it’s sticking ! 1:04 pm dec. 5

  8. Lee Wilson says:

    I just wanted to share with you this video of what we got this morning. Temps were 36…we hit 39 and now are at 37.

    I guess video and pics speak louder than words.

  9. cgavic says:

    At Sandy/1,000 ft. heavily snowing and 2″.

    The snow level was at 1,500 sunday.

  10. Saw a dusting of snow in Monmouth this morning. Up in Newberg, the snow is only really limited to the stronger showers. It makes for a good sight during a slow day at work!

  11. Washougal1100ft says:

    Crazy I live right across from Corbett in washougal and it has been snowing since 6:30 this morning and we have close to 3″ the lawn is completely covered and trees! I also work in town and there is sticking snow all the way to sea level I was kinda surprised.

  12. Paul Bo9 says:

    Glad I didn’t have to make that forecast but as someone who pays attention I’d say you did a stellar job Mark.

  13. Well, it’s shaping up pretty much as I thought based on the models. Despite some commenters’ initial negativity, it was indeed cold enough for at least flakes in the air at many lowland locations this morning. I briefly had all-snow and I’m only at 100 feet elevation.

    Now on to Round 2 (for me, Fraser outflow interacting with weak onshore flow) tonight and Round 3 (for most of us, incoming Pacific front overrunning cold air in-place) on Thursday. Like this morning, neither chance will be super-cold or long-lasting. NWS isn’t forecasting me getting colder than 27 degrees F all week.

    Let’s hope this is just a preview of a bigger event later this month which some model runs have been hinting at.

  14. Windsday says:

    The only snow most of us are going to see is on this blog. It’s too early for snow. Models shmodels. Stick to climatology.

    • Many of us have already seen snow today. Read the other comments. And there will be more chances later this week.

    • W7ENK says:

      Kyle… your pills… quickly!

    • I keep a running list of the best comment replies I’ve encountered on the Interweb. I “sample” them occasionally when I’m motivated to reply but lack an articulate, clever response. Kyle… Your pills… Love it! 🙂 You are a ham!

    • W7ENK says:

      Indeed, I am!

      Unfortunately, the sad truth is, he actually does have some pretty serious psychological issues that he and his family keep managed fairly well with medications, most of the time. There are times, however, it becomes obvious that he either needs an adjustment to his meds, or he stopped taking them altogether. His posts to this group begin spiraling deeper and deeper away from reality, and then he disappears for several weeks. It’s an odd cycle, one that’s been interesting to witness as its evolved here over the years.

  15. HAWKEYES23 says:

    Thursday could really be a mess. From what some are saying.

  16. Diana F. says:

    300 feet in East Vancouver, been snowing from 1030 am to present 11:15). All snow though the showers are light, damn it (oops sorry Santa), but it’s sticking to the ground and house and cars with what I shall call under an inch so far. HOWEVER everything is white and cold and it’s beginning to look a lot like Christmas! But I am already sad it will be going away soon. Meanwhile I bet our 8 year old and all her friends at school are going CRAZY right now!! Snow at school snow at school! A day she shall always remember as she too is a weather geek! (And proud of it). Now for the end of week forecast! Yeehaw!

  17. oldwxwatcher says:

    All snow (wet, sloppy) here in East Portland. Was in Gresham a while ago but it was only a slight mix there.

    Check out this Meteogram for 12/15-12/21. It will no doubt change many times before we reach these dates but how epic it would be if it were to actually occur. http://www.wxmaps.org/pix/pdxgfsb.png

  18. Max in Fairview says:

    Have all snow now.

  19. Gene says:

    Snow coming down heavier in east Gresham — starting to stick on lawns/bark dust/ etc.

  20. Alohabb says:

    Corn pass in Hillsboro is slushes up. Corn pass and skyline is all white. Cars off road, crashed. A mess

  21. W7ENK says:

    Finally, seeing about 10% sloppy wet snow mix/90% heavy rain at street level in Downtown Portland. After standing straight out toward the North all morning, the flag atop the Umpqua Bank building finally went slack.

  22. Ken in Sheridan says:

    Best heavy, wet snow of the morning for last 20 minutes or so. Beginning to look a lot like Christmas!

  23. Gene says:

    Just turned to snow in east Gresham. Not heavy, not sticking, but still fun to see

  24. W7ENK says:

    SPECIAL WEATHER STATEMENT
    NATIONAL WEATHER SERVICE PORTLAND OR
    947 AM PST MON DEC 5 2016

    https://inws.ncep.noaa.gov/a/a.php?i=7414990

    AT 940 AM PST…A BAND OF HEAVY SNOW WAS LOCATED ALONG A LINE EXTENDING FROM MEADOW GLADE TO NEAR GRAND RONDE. MOVEMENT WAS SOUTHEAST AT 10 MPH. THIS BAND WILL CAUSE ROADS TO BRIEFLY BECOME SNOW COVERED. IN ADDITION, VISIBILITIES WILL QUICKLY LOWER. 

    • W7ENK says:

      LOCATIONS IMPACTED INCLUDE… HILLSBORO… MCMINNVILLE… OREGON CITY… BATTLE GROUND… WASHOUGAL… SHERIDAN… VANCOUVER DOWNTOWN… PORTLAND DOWNTOWN… PORTLAND… VANCOUVER… GRESHAM… BEAVERTON… TIGARD… LAKE OSWEGO… TUALATIN… WEST LINN… NEWBERG… FOREST GROVE… MILWAUKIE AND WILSONVILLE.

      HIGHWAY 26, AND 30 AS WELL AS I-5, I-405, AND I-205 WILL ALL BE AFFECTED.

    • Milwaukie… LOL good one.

    • runrain says:

      And I’m looking at your building right now, Erik, and it is snowing, albeit very wet and mixed at times.

    • W7ENK says:

      You’re in the Umpqua Bank building, right Runrain?

  25. Anonymous says:

    been snowing for an hour in hillsboro, starting to get a dusting on the otherwise really wet pavement in the parking lot.

  26. Katrina Bruland says:

    At Cornell and Skyline: snowing heavily for about 20 minutes, temp down to 32 from 34, half inch on deck. 🙂

  27. Right now my part of Forest Grove is a winter wonderland. Snow is sticking everywhere.

    • So did my more optimistic forecast. Looks like this event simply didn’t deliver the goods for Portland. Even up this way, it was (as expected all along) a marginal event.

  28. You sure about that?

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