Wednesday PM Snow Update

WE”RE ON SNOW WATCH!

Sounds exciting, but you know what that means…in this case just some real light stuff early Thursday.  Most likely kids won’t be sledding on inches of snow tomorrow morning.  In fact it’s unlikely we get even as much snow as we saw back in mid December.  BUT, we’ll see snowflakes in the air again and in Portland that’s exciting!

THIS EVENING & OVERNIGHT: 
We go mostly dry, just a few rain showers through 8pm, then nothing going on through most of the rest of the night.  Ice on roads probably won’t be a problem with not much falling out of the sky, but something to watch.  Low around 34.

TOMORROW MORNING 6-9 AM: 
A burst of showers may arrive, if so it would be all snow and could stick.  The main issue is there just isn’t a lot of anything falling.

Lowest elevations:  NOTHING TO A DUSTING
Near/above 1,000′:  DUSTING TO 1″  (could be some snow-covered roads at the top of the West Hills/Mt. Scott/Sandy etc…)

THE REST OF TOMORROW:
Partly cloudy with a flurry or shower possible, a real quiet weather day.  High near 40

Here is the snow accumulation forecast from our RPM model (18z version), it doesn’t exactly inspire confidence in a snow day for the kids or teachers:

RPM_SNOWACCUM_METRO

MarkSnow_PortlandOutlookPercentages

I’ll blog later about the possibility for snow BEYOND tomorrow and Friday…

Chief Meteorologist Mark Nelsen

141 Responses to Wednesday PM Snow Update

  1. Jordan (Raleigh Hills, 420') says:

    Just went to the store and the car was all frozen. Roads still appear OK, but it’s dropping quick! Could def get icy tonight, I still have puddles.

  2. alohabb says:

    33 here now and streets still have a little moisture on them. Uh oh.

  3. alohabb says:

    I bet Mark is pacing in front of the green screen as we speak wondering” do i say
    Snow or not” ” will there be utter chaos”… ” cant wait to get home and watch final Jersey Shore episode”

  4. swift says:

    The new 00z GEM just proved the 00z GFS was indeed weird and an outlier, also shows nice moisture even for Sunday morning. :)

    • If the ridge is supposed to drift east I can’t see energy digging south along 130 W when the ridge axis is at 140 W, you know? ….. So a track just offshore or right along the Coast makes the most sense to me.

    • Traci says:

      And is that what we want Rob? The one that makes the most sense to you?

    • swift says:

      Yea the GFS and especially the Euro are too biased when they dig troughs to much SW. There is no way the 00z GFS verifies.

    • Benjamin (West Salem) says:

      I’m not Rob, but I think I know the answer… maybe, lol ;) Yes, if the track is just offshore would leave us in a colder offshore flow, but the low would still be close enough for perhaps some decent snow.

    • W7ENK says:

      Hey, maybe we’ll get really lucky and the center of the low will get hung up around the mini death ridge that always gives incessant 90 degree temperatures to the South facing wall at the Tillamöök Cheese Factory?! :mrgreen:

    • alohabb says:

      Mmmmmmm….cheese.

  5. exciting night joy
    back lit snow shower star views
    grand nature sighting

  6. Hmmm…….
    AREA FORECAST DISCUSSION
    NATIONAL WEATHER SERVICE PORTLAND OR
    900 PM PST WED JAN 9 2013

    THE NEXT SYSTEM OF INTEREST DROPS DOWN ALONG THE COAST SATURDAY INTO SATURDAY EVENING. WITH THE MODELED TRAJECTORY THERE WOULD BE NO ONSHORE FLOW SO IT APPEARS COLD ENOUGH FOR PRIMARILY SNOW ACROSS THE INTERIOR. THE COAST LOOKS MARGINAL BUT PRECIP WOULD LIKELY ALSO FALL AS SNOW…PARTICULARLY ACROSS THE NORTH COAST. MOISTURE LOOKS TO BE THE QUESTION MARK. THE LATEST GFS MODEL IS PRETTY DRY *BUT ALSO LOOKS PRETTY WEIRD.* **–>THE 00Z NAM LOOKS MORE REASONABLE AND WOULD SUGGEST A WIDESPREAD 1-3 INCH SNOW EVENT FOR THE INTERIOR<–**…WITH PERHAPS MORE THAN THAT ACROSS THE CENTRAL AND SOUTH VALLEY. AGAIN…MAY HAVE TO WAIT A FEW MODEL RUNS BEFORE THE ANSWER IS REVEALED.

  7. swift says:

    The NAM is the far superior model in the near term and that is why I love our snow chances this weekend. I am calling for a total of 3 to 5 inches down to the Willamette valley floor Saturday afternoon to Sunday morning. Those you of who live on the hills will see 6+”.

    • germantownsummit1000' says:

      Those of us who live on the hills will see….

    • Sw says:

      Any thoughts on any Arctic outbreaks. I am guessing were getting a little to far into the season (for this part of the world), unless we see something like the Omega effect(1989); I believe this is very rare though.

      Thanks,

  8. *BoringOregon* says:

    Its about, 35 and droping out here. Might have some Icy Roads in the Morning I bet. I was wondering I want to get into model riding to but there is not that many, Youtube videos on it ? I was wondering if some body could make a Youtube video explaining on how to read one just wondering??

  9. SNOW! says:

    EVERYONE WHO WANTS SNOW, WHERE YOUR PAJAMAS INSIDE OUT!!!!!!!!!!!!!!!!!!!!

  10. paulbeugene says:

    GFS clearly favors SW Oregon in terms of precipitation…Medford could have itself a nice snow event…..it is fair to say, in terms of operational runs…that it is the farthest west with the low, compared to other models…ECMWF, NAM, UKMET, GEM, etc. That RPM seems to be in the GFS camp with low precip..can’t ignore it I guess.

    At this point, with the Saturday evening/night event…it looks to me that western half of Willamette Valley has the best odds of snow accumulations….the Euro may have other ideas…and if the GFS trend is valid…then southern locations such as San Eugenio may score…or be dry altogether like PDX..hope not.

  11. W7ENK says:

    YAY for wet grass and pine needles!!

    http://i47.tinypic.com/2ypcbic.jpg

    I expect more of these conditions throughout the weekend, and possibly some significantly higher accumulations of strong to severe disappointment.

  12. Alan says:

    Is the latest snow talk about Thursday or Saturday? 70 miles west? RPM dry? NAM vs. GFS? Not sure which day everyone is talking about? Thanks!

  13. swift says:

    I may also add the NAM is far superior to the GFS with little fine details in the short term because its higher resolution and that way it takes into improved parameterization of surface and precipitation processes. It’s obvious to see that tonight the 00z GFS is confused, there is no way that leading system shows up out of nowhere and does that.

  14. swift says:

    The NAM is a better short term model predictor because its higher resolution.

  15. It’s a classic battle ensuing, one for the ages no doubt. NAM vs GFS. Who will win? NAM does pretty good handling these features. Oooo stay tuned oooo the plot thickens.

  16. Mark had better be careful that he not play into the “Half an inch in the city, OMG SNOWMAGEDDON!!!!” archetype on the news. It’s just a CHANCE for some BRIEF LIGHT snow, folks. We don’t want to set off a ‘Portland snow panic’ at the supermarkets, hardware stores and tire centers. :p

  17. swift says:

    Calm down everyone, the 00z GFS is trying to follow the trend of moving the weekend systems up, so it totally doesn’t take into account the trailing system and puts all its energy on the leading system. What might end up possibly happening is both systems combing to produce a super system where we get 6+” here on the valley floor. Just something to keep an eye on, if this happens I’ll be the first one to take credit for this excellent analysis because we’ve seen systems combine before at the last minute…..

  18. Tyler Mode in Battle Ground says:

    The GFS is further west with the low than the NAM, keeping things much drier.

    I did take special note that the graphic that calls for snow % says through tomorrow….and does NOT include Saturday :)

    • Yeah, it is further west, but not by much 70 miles? Seems to imply a possible secondary system Sunday too. Also, note it’s colder on this run with modified arctic air into eastern Washington and Columbia Basin. You watch we’ll get a dusting and much colder temps with east winds modified arctic air via Gorge.

    • Mark Nelsen says:

      So is our RPM, totally dry.

    • W7ENK says:

      BOOO! Hisssss!!!

      *rotten tomatoes*

    • Tyler Mode in Battle Ground says:

      I’ll take cool and dry any day. Today was much more grey than I thought it would be. Most of the day (7a-4p) was in the upper 30s with rain.

    • I dunno, looking at the current satellite I’d say the showers don’t shut off over night and the bigger batch coming down is faster than forecast by several hours. I’m thinking snow at very low elevations in the wee hours tonite-tomorrow. That’s good because it happens during the coldest part of the night. Bad because most of us will be snoozing away only to wake up and say “look, it snowed” as the sun peeks out and starts to melt it all away.

    • Ben T says:

      Well, I’ll be working. So maybe I’ll see something.

  19. Longview - 400 ft says:

    Finally down to 35.8

  20. paulbeugene says:

    Using latest model guidance

    NAM mm5 00Z shows snow in southern willamette valley, about 1-2 inches tomorrow….

    NAM (from NCEP) shows excellent track of low for snow for much of western oregon, from Cascades westward…with amounts of 2-5 inches possible..most on the east slopes of Coast Range….Vernonia…Forest Grove, Banks….Dallas….Corvallis look the best.

  21. Alan says:

    So what’s up with Saturday’s snow? Is it going to be a dud like Thursday’s? Word on the street (er..TV) doesn’t sound very good. KGW says unlikely. I guess Mark will post about it soon.

    • David B. says:

      NWS says it’s actually looking like a better and better chance all the time. I already posted the relevant excerpt from the Seattle forecast discussion. Here’s the excerpt from the PDX discussion:

      THE NEXT SYSTEM OF INTEREST DROPS DOWN ALONG THE COAST SATURDAY INTO SATURDAY EVENING. THE MODELS SEEM TO BE CONVERGING ON A TRAJECTORY NOT TOO FAR FROM THE COASTLINE. IF THIS IDEA CONTINUES…THERE IS A GOOD SHOT OF LOW ELEVATION SNOW LATER SATURDAY AND ESPECIALLY SATURDAY NIGHT.

    • Dave South Salem 500' says:

      I’d like to know what First Alert Storm Team has to say about all this.

  22. paulbeugene says:

    00Z NAM at 63 hrs still shows the snow event for Saturday night…with the low on a track a bit farther west (but not too far)…which is good…should be good moisture with this…and a bit cooler.

  23. chiefWright (Marquam) says:

    Frozen Precip Alert!
    Some of those showers are packing some pretty thick rain south of Canby; wiping off the windshield in chunks. It was several notches away from true snow, let alone anything sticking, but hey, it’s a start.

  24. SNOW! says:

    I live at about the 350′ elevation on bull mountain. What is the chance of getting an inch tomorrow morning, and what do you think the temperature will be tomorrow morning when the moisture comes?

  25. Jordan (Raleigh Hills, 420') says:

    Time for OBS? 37 outside Beaverton. Temp has dropped a good 4 degrees in the past two hours, otherwise has been steady since 8 am…

    looks like lots of little showers offshore and a small feature swinging south out of coastal BC. I think we’ll get something out of this tonight, a dusting probably. Hoping some snow will still be flying when the sun rises in the morning.

  26. W7ENK says:

    Syria, Israel, West Bank and Jordan endure heavy snowfall

    http://www.huffingtonpost.com/mobileweb/2013/01/09/mideast-winter-storm-2013_n_2437186.html

    And yet, we’ll be lucky to get just a dusting? There’s something wrong with this picture… :(

  27. Ryan says:

    Very heavy sleet shower just passed thru Bethany area.

  28. Temp down to 33 Rain starting to change over to snow now gotta love the good ol p.s.c.z hopefully it stays put for awhile now since were finally into night time and cold air from the north.

  29. Pretty good enhanced activity peeling off Vancouver Is. heading south. That must be the source for a period of heavier precip in the early morning.
    http://www.atmos.washington.edu/~ovens/wxloop.cgi?ir4km_enhanced+12

  30. David B. says:

    A snow day Saturday in Pugetopolis? From the most recent Seattle discussion:

    THE PATTERN ON SATURDAY REMAINS INTERESTING BUT ALSO HIGHLY UNCERTAIN. ABOUT HALF THE MODELS CONTINUE TO DIG A SHORT WAVE THROUGH THE AREA IN NLY FLOW WHICH COULD POTENTIALLY PRODUCE WIDESPREAD 1-3 INCH AMOUNTS. THERE ARE OTHER MODELS THAT TAKE MOST THE ENERGY OFFSHORE AND WOULD RESULT IN NO SNOW AT ALL OR PERHAPS JUST NEAR THE COAST. HOPEFULLY MODELS WILL START TO COME INTO BETTER AGREEMENT AS WE APPROACH THAT TIME PERIOD. KEPT A CHANCE OF SNOW IN THE FORECAST WITH SOME LIKELY POPS TOWARD THE COAST.

    We’ll see…

  31. JERAT416 says:

    Now, why can’t the forecast be something like this (not so professional sounding). “Cold arctic air has completely blanketed the NW from northern washington, to northern california, as far east as Boise. Without this arctic air, we would be forecasting a wet, blustery day with 1 to 2 inches of rain for the metro area, and 3 inches in the cascades and coast. However, there won’t be a place (even at the beach) within 300 miles that isn’t covered with a large blanket of snow. This snow day will probably go down as being one of the single largest snow days in portland history, get the chains and studs on now!”

  32. A guy at Dutch Bros told me it’s gonna snow tonight because his iPhone said so, and iPhones are always right. I reminded him of the navigation that came his phone…

  33. Marcus says:

    Just went from 42° down to 35° with the ice pellet shower ice all over the ground nice! In LaCenter

  34. paulbeugene says:

    Mark: was does RPM say for snow in Eugene…the 3 day regional map (18Z) is totally blank…hopefully it is not zero point zero

  35. snodaze says:

    Models continue to show the ridge retrograding 21st thru 26th. — details and timing the only (usual) issue… But it is there. run after run… we’ll see. — cross your fingers I guess… Would like to see a repeat of ’08.

    ** What ‘will’ likely happen? — That feature keeps getting pushed back until a low pressure center undercuts it.

    But I keep thinking back to the post Boringlarry had a few days ago from an AFD out of Buffalo (or somewhere over there)

    • Ron says:

      As long as the cold air hasn’t already slipped into the mid-west and we just get left overs. That’s my concern.

  36. swift says:

    Forecast updated for Saturday says P.M. Wintry Mix, so you think we also see sleet or freezing rain?

  37. According to the n.w.s 1-2 inch snow tonight from north seattle up to bellingham. Than another 1-3 on staurday if it holds and happens i be surprised But excited. Temps dropped from 41 now 36 in the last 20 mins winds coming more out of the north so just maybe they will be right fingers crossed.

  38. W7ENK says:

    .1″ in Milwaukie? C’mon Mark, you know better!

    That 0″ in Hillsboro ought to make Yev happy! :lol:

    • germantownsummit1000' says:

      That’s a typo – actually, it’s -.1″ in Miltucky

    • W7ENK says:

      Does that mean I have to give back the .1″ of slush I logged last winter?

    • runrain says:

      Milw Chamber of Commerce will be handing out free magnifying glasses so that residents will be able to observe tonights snowfall. Proof of residency is required.

    • pappoose in scappoose says:

      Hahaah! Yer killing me, runrain!

    • Lurkyloo says:

      Runrain, you’re funny.

    • germantownsummit1000' says:

      “Does that mean I have to give back the .1″ of slush I logged last winter?”

      If, by “…last winter…” you mean this winter (as in Dec. ’12) then YES!

      C’mon, we all know you’ve got it in a Ziploc in your freezer.

      “Proof of residency is required.”

      That’s observer suppression!!!

    • runrain says:

      W7ENK will be handing out VooDoo donuts!

    • W7ENK says:

      No, not December 2012, I didn’t get anything last month, so that would mean I’d have to dig back to last March to pay off any debt.

      And you’re right, I have lots of ziplocks in my freezer! Strawberries, blackberries, hot dogs, ribeyes, drumsticks… lots of stuff, actually! Which one were you referring to?

    • germantownsummit1000' says:

      “No, not December 2012, I didn’t get anything last month, ”

      I’m so, so sorry. I forgot about the Dome – and I’m extra, extra sorry you didn’t get any…

      …snow, that is.

    • Ben T says:

      Hahaha!

  39. germantownsummit1000' says:

    Are you sure it won’t be early late Thursday?

  40. gidrons says:

    Not going to stick your neck out on Saturday?

  41. Ralphdoggy says:

    First?!

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