Winter Storm Watch: Snow/Ice Likely Later Thursday

5pm Tuesday…

The NWS has issued a Winter Storm Watch for much of Western Oregon between the Coast/Cascade Ranges for Thursday and Friday.

markwarningswinter-wx

That means snow and/or freezing rain is POSSIBLE during this period but some of us may not get it, or get much of it.

We’re still two days away, but models have come into much better agreement on the general sequence of events the next 4 days:

HIGHLIGHTS

  • Wednesday will be colder with a very strong east wind spreading out across the metro area
  • Wednesday should be a dry day, or mainly dry.  Possibly a flurry/sprinkle in the afternoon that WILL NOT AFFECT ROADS.
  • Thursday AM should be dry as well for a clear AM commute.
  • At some point Thursday afternoon or evening, snow will spread north across Western Oregon and up into SW Washington.  Timing is TBD since we’re still 2 days away.
  • First guess (still 2 days away!) is 1-2″ snow for many of us in the western valleys before a transition to freezing rain by Friday AM.  If the transition takes longer?  More snow, less freezing rain.
  • During the day Friday, freezing rain is likely at times, but it’ll become confined to near the Columbia River Gorge (central/east Portland metro area) as temperatures rise above freezing in most other locations.
  • It’s possible that Friday afternoon many of us will see mainly wet roads south/west/north metro away from the Gorge.  This happened during the last two freezing rain events when we thought a large area would see freezing rain and instead it was confined to the central/east metro area.
  • A warming southerly wind late Friday night or early Saturday ends the freezing rain threat outside of the Gorge at that time.

ROADS/SCHOOLS

I see either Thursday evening and Friday morning commutes being a possible big issue anywhere in the valleys.  Friday could be a no-school day for many.  It could possibly still be very icy in parts of the metro area Friday evening too.  Again, we’ve got another 24-36 hours to fine-tune the forecast

 

WEATHER GEEK CHAT

Here we go again, hopefully for the last time this winter.  It was nice to see models come together pretty well on last night’s runs, and the same thing through this morning/midday runs too.  No model is showing any sort of significant snow now tomorrow through Thursday AM.  After checking several model’s thermal profile up through the atmosphere, I’m becoming convinced this will be more of a freezing rain “storm” than a snowstorm for most of us.  I think just about everything I checked shows that warming occurs overhead before sunrise Friday, so all of Friday’s precip will be in a liquid form.  That’s at least while falling.  Of course if surface temps are below freezing then you get the ice glazing which we’ve seen 3 times already this winter in the valleys!  Check out snow forecast from the GFS:

gfs_snow_fridaypm

The ECMWF

ecmwf_snow

and the WRF-GFS

wrf_snow_fridaypm

None show more than 2″ anywhere in the western valleys.  That’s due to warmer air coming in overhead…not “warm”, but warmer.  Then the next question has been “how cold will the air mass be that moves in on the east wind?”  I see several hints that it won’t be as cold as previous events in January.  The result could be that it’ll be easier to get temps above freezing over a larger area west of the Cascades during the daytime Friday, even with the easterly flow continuing through the Gorge.

I know we are all focused on snow and freezing rain, but I need to mention the strong wind tomorrow too.  Check out the cross-section from the WRF-GFS for the next 3 days.

kpdx-th

The solid wind barbs represent 50kts and each little barb is 10 kts.  So from tomorrow morning through Thursday evening easterly wind is forecast to exceed 60 mph over our heads…up around 2,000′.  Some of this strong wind will surface as gusts around 40-50 mph.  Of course this means we’ll see a few limbs/trees come down, especially across the east side of the metro area.  Since we’ve already seen wind this strong this winter I doubt we’ll see widespread power outages.  But regardless, it’s going to be a gray and chilly afternoon Wednesday.  It’ll be a big reminder that winter isn’t finished yet!

Chief Meteorologist Mark Nelsen

 

56 Responses to Winter Storm Watch: Snow/Ice Likely Later Thursday

  1. Anonymous says:

    OK mark, delete posts again?

  2. marinersfan85 says:

    Whatever happens tomorrow, I’ll remained unphased. This winter already has an A+ in my book.

  3. Lurkyloo says:

    No comments from Poose? What’s up with that??

  4. Lurkyloo says:

    Wicked Wind of the East is having another baby fit. I’m probably a mile west of I-205 and it’s just raging here.

  5. Joshua Downtown PDX says:

    According to my very uneducated analysis, this event seems like it’s going to bust. There is very little moisture to work with until later on Friday when the overhead and surface temps are too warm to support frozen precipitation. The 12z NAM, GFS, and RPM are showing 0 – .5″ of snow. I think we will get a trace of snow along with maybe a few hundredths of an inch of ZR before we thaw. I hope I’m wrong.

    • runrain says:

      I don’t think it’s going to be cold enough either. Also, my uneducated guess.

    • Scooter says:

      This “event” is going to be just what it is; neither “bust” nor boom. Weather is a constant event ever changing, neither good nor bad just the physical atmosphere of earth in flux.

    • JF says:

      The models have had trouble assessing moisture potential in these situations, as has been evidenced painfully twice this winter.

    • Dave in South Salem (500') says:

      Might not be cold enough or wet enough. Otherwise its good.

    • Anonymous says:

      Probably close to the mountain areas or Gorge, snow ice may show up .
      The rest of the area, I agree that too warm still and latent heat around to prevent much of anything.
      Hopefully the masses will stay home all day and Friday due to the reports.

  6. W7ENK says:

    Okay, so here’s my annual synopsis of January 31st.

    Despite my best wishes, t’was yet another birthday without snow. That makes 38 consecutive now, 100%

    It hasn’t snowed on yesterday’s date in Portland since 1975.

  7. Alohabb says:

    This east wind is raging more here at my place now than it was at the last event. The gusts are far more greater in Aloha than last time. Sustained wind speed is greater as well.

  8. Anonymous says:

    Here we go again!
    The Guesswork machine with its “models” to select their pick from.
    I can easily see how a weatherman can swap out jobs with a stock broker position.
    Have a nice day.

  9. Anonymous says:

    Here we go AGAIN!
    More GUESSWORK and “the models we are using” routines.
    Reminds me of the stock brokers on TV, “Buy and hold” Intel stock When it was at $150.00 a while ago.
    Great advise!
    Have a nice day.

  10. Abigail says:

    How’s the drive from Portland to Astoria mid-morning Saturday?

  11. muxpux (Longview) says:

    My work consolidated outlet shifts while we transition to new equipment, and we are working 4-10’s. so I’m off Friday. Let it snow!!!!

  12. Jake-(Gresham near Nadaka Nature Park) says:

    Just got finished looking at the Euro. Trajectory has largely changed for the low pressure system. We are even more so in the green light according to its output:

    Friday:
    http://www.pivotalweather.com/model.php?m=ecmwf&p=sfcmslp&rh=2017020100&fh=48&r=na&dpdt=

    Saturday:
    http://www.pivotalweather.com/model.php?m=ecmwf&p=sfcmslp&rh=2017020100&fh=72&r=na&dpdt=

    Note the movement is now bringing the system ashore over / just South of PDX (which gives us more moisture to play with). This is slowly turning out to be a significant event and not just a glancing blow. Widespread snowfall.

  13. David says:

    What is the consensus on the Cascades? I have to travel to Bend on Friday, but not sure if it’ll be too hazardous to make the trip.

  14. bjvanwash says:

    Any thoughts on Mon/Tues? Looks really interesting..

  15. John says:

    I understand the uncertainty in forecasting when conditions are at the margins. Mark gives me better and more timely information than any other source. What I take away from the latest forecast is that I need to be prepared for possible snow or freezing rain on Thursday or Friday. That is valuable information, it helps me plan my work travel and my kid’s school travel. If we don’t get much, no big deal. If we get more, I’ll be prepared. Can’t ask for much more on Tuesday.

    • John says:

      Of course what I really want is a nice sleddable snowfall in east metro at 250′ that sticks around for a couple days then melts quickly by Monday. And a pony. I want a pony.

  16. WX Ninja says:

    It will be interesting to see what the Temps are during the precip. If we stay around the freezing mark then roads may not freeze over as they will be a bit to warm as they tend to stay a few degrees above the temp. Another wait and see scenario it seems but that’s just been the story this winter.

  17. marinersfan85 says:

    Well tonight’s set of models have really sucked. Hopefully the Euro bails us out.

  18. Josh "The Snowman" from Gladstone, OR says:

    Yep. And you were so positive last time that most places may see an inch or two. Trace most places.

    Let’s just realize at this point that PNW forecasting is 50/50 and prepare for the worst. It is very irresponsible for Mark and other forecasters in the area….IE; Rod Hill, to tell people it isn’t a big deal.

    What I see on satellite at the moment is cold air pouring down south eating away at the offshore low pressure system. It will eventually move in, most likely with a lot of low level cold to work with. How cold? Mark, and know one else knows.

    Get away from your models for a second and look at what is happening in real time… Good lord.

    • Ash Qelon says:

      Need to realize the tabloid media it is dispensed from .
      They are a very unstable & confounded bunch on matters so reality on anything.
      A lump of leven leaveneth the WHOLE lump!

    • jimbo says:

      ???? For years Mark has had the best record in forecasting these events by far! Shut up and let him do his job

    • marinersfan85 says:

      He posted this on western like he’s some clever funny guy or something.

    • Josh "The Snowman" from Gladstone, OR says:

      I remember when Mark was a kid basically. Working as Jim Bosley’s understudy. Don’t embarrass yourself. They had much less information at their disposal then. Lets be real.

      Mark knows damn well that we could see from nothing to a foot at the moment.

    • Anthony says:

      I remember him working with Jim Little. I visited both of them at the KOIN Tower.

    • JF says:

      So Josh, what would you suggest? A forecast for
      between 0 to 14 inches of snow. Get real.
      Look up the word forecast. Mark does a great
      job as you probably actually know.

    • Scooter says:

      Now now boys and girls let’s not get too serious, and try to be civilized. After all it’s just a silly little weather blog, nothing to get aeriated over.

    • bobob says:

      I have to say this is one of the rudest comments I have ever read. Mark is one of the best. I am sure from your chair you are able to out do him though. Wow….. Take a chill pill Josh. This air mass is not that cold. Mark is probably right.

  19. Windsday says:

    My raingauge actually recorded fourth hundredths of precip from a bit of drizzle coupled with a lot of hill mist. Any elevation gains got into the light rain category.

    It was very reminiscent of being in the midlands of England of what they would describe as a dull winter day.

    • Dave in SW PDX (235') says:

      I agree. It was gray & drizzly here most of the day, too. The only thing missing was some fog. Currently 37° with .02″ in the rain bucket. The calm before the storm?

  20. …just finished shoveling another 6 inches of unfinished winter off my driveway and paths….total depth back up to 20 inches…

  21. Dave in South Salem (500') says:

    So the GFS gives Albany a brutal dome and the east valley foothills a nice storm. The ECMWF gives us the classic warm tounge of rain in the east valley foothills. And the WRF taketh away all snow except for the far west valley and the PDX city limits. How do you reconcile all that?

  22. Well one good thing though is that the temps here and on the east side are much warmer than earlier this month. Spring may start in May this year.

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