Super Bowl Sunday Super Sized Snow For Some Of Us

Some nice alliteration in that title eh?  Ridiculous I know, but I couldn’t stop myself on this Saturday morning at 11am.

Luckily we avoided an ice storm for MOST of the metro area yesterday and most of the forecast in the end worked out just fine.  Tons of ice for the morning commute and then by the afternoon most areas were clear except right around/in the Gorge and up in the higher hills.  Of course the cold air lingered longer than expected right along the Columbia River…PDX Airport ended up with .30″ ice and poor Troutdale had .81″ once it was done just before sunrise.  That’s the 4th ice storm along the Columbia River this winter!

Let’s add it up: We’ve had 2 snow/ice events in December, 3 in January, and now 1 in February.  That’s a total of 6 times we’ve dealt with ice and/or snow (or a combo) so far this winter right here in the city.  We haven’t seen a winter like this in the 26 years I’ve been forecasting in Portland.  That doesn’t count 2-3 other wet snow events in the higher hills too.

Tomorrow through Monday morning will likely be #7.  This time you can forget freezing rain, it’s all about 32-33 degree snow under a calm wind.

What’s the plan?

It’s going to  rain a LOT Sunday and Sunday night west of the Cascades where most of us live as a stationary front sits along a line from near Newport to The Dalles.  Subtropical moisture will be riding up along that front = juicy with lots of precipitation.

Check out model forecasts of total precipitation the next few days, most of it is done by Monday morning:

rpm_rain_nworegon

A huge soaker right?  In fact there could even be some localized flooding with this kind if rain intensity.  During the daytime Sunday that front is hung up somewhere across the NW corner of Oregon.  The location is slightly different on each of our models; here’s the ECMWF temperature plot at 4pm (middle of Super Bowl):

ecmwf_temps_4pmsunday

50s in the southern Willamette Valley, but cold enough for a very heavy/wet snow from the Portland metro area north! Is this rare?  Yes, the last time I’ve seen a situation like this was March 21st, 2012, the “Spring Break Surprise”.  Actually it was a couple of days before spring break started, but close enough for a clever name.  Nice pic…

capture

That was a big snowstorm in the central/south Willamette Valley and is now known as the latest snowfall ever at PDX Airport.  You can see looking at that map how a very slight movement north or south will make a HUGE difference in snowfall totals (and who gets a heavy cold rain instead) for the daylight hours Sunday.  Now Sunday evening and night the whole front shifts south as a cold front, which means probably ALL of us in the western valleys get at least some snow.  The big question is who gets pounded with a heavy wet snow and who gets just heavy rain tomorrow during the day.  The short answer is:  We don’t know for sure yet, but north of Portland is looking like the surest bet for daytime snow at this moment.  In this pattern the coastline can get the heavy snow too since there is no warming onshore wind.


SUMMARY

All areas west of the Cascades in the lowest elevations (including the coastline) see steady rain to start Sunday morning

Many areas from Portland/Tillamook north (including Astoria & Longview) may switch over to a heavy/wet 32/33 degree snowfall the rest of the day with many inches possible

The Portland metro area MAY see a switch over to snow during the day; best chance for that will be as you go up in elevation into the hills.  We’ll know more after evening models come in.

South of the metro area a switch to snow is less likely during the daylight hours, but still a possibility

All areas at the lowest elevations along I-5 from Olympia to Albany will likely see at least some snow on the ground by late Sunday night and for the Monday AM commute since we’ll all cool close to 32 degrees

There is a high potential for a heavy/wet snow storm anywhere above 1,000′ in SW Washington and NW Oregon.  There will be locations that see 10-20″!

There is a decent potential that some location somewhere along the I-5 corridor at the valley floor (somewhere between Albany & Olympia) and some city along the coast north of Pacific City will see a foot of snow on the ground by Monday morning.  We just don’t know exactly where at this point.  


Due to the potential that just about any area could see the big snow, the NWS has issued a Winter Storm Watch for all of us westside.  That doesn’t mean everyone is going to get heavy snow, but it’s just a “hey, keep an eye on the forecast” type of watch.

Because of the possibility we could have some sort of historic heavy wet snowstorm in the lowlands, I’ll be working tonight on the 10pm newscast.  Of course I’ll be in tomorrow as well.

Stay tuned because it’s going to be a wild ride for some of us the next 48 hours!

My guess is that you’ve seen different maps on social media floating around showing snow totals from models.  I’ve included a bunch here.  They are all different because each model has a slightly different location for the front, a low passing by to the south Sunday evening, and physics. They each calculate snow in a different way too.  You get the idea…someone is going to get nailed by a big dumping of snow!  By the way, the Cascades have several feet coming too.

ecmwf_snow_monday10am nam_wrf_4km nam_wrf_3km_parallel wrf_snow_mondayam rpm_snow_12z

 

Chief Meteorologist Mark Nelsen

 

 

 

81 Responses to Super Bowl Sunday Super Sized Snow For Some Of Us

  1. pgiorgio says:

    1 to 4 inches for Portland. Mark will make his next post with 1 to 4 inches as the forecast.. Just a wild guess

  2. boydo3 N Albany says:

    The Cascades will be seriously dumped upon no matter what. And that’s a good thing..
    Relax and have a homebrew 😉

  3. BeaverDreams says:

    And just like that…..snow potential gone. Amazing how the models teased us so late in the game. Portland weather sure is capricious.

  4. marinersfan85 says:

    Can’t win them all. Looks like Centralia scores. Cold rain for everybody South of battle ground.

    • Sapo says:

      possibly, if you believe the 00z GFS and completely discredit the RPM and NAM

    • marinersfan85 says:

      Euro has stayed north for a few days. Everything has trended North. It is what it is.

    • Scooter says:

      Need I remind you folks, this isn’t a video game, this is really just simple weather no more no less, something that happens in the atmosphere minute by minute I don’t believe for an instant that some team in Centralia scores against some other less fortunate team down south. It all seems just a little disconcerting that we have trivialized our lives down to one possible outcome our day to day weather. After all we really do have a big game tomorrow!

    • Mark Nelsen says:

      See, a nice positive comment!

    • Jake-(Gresham near Nadaka Nature Park) says:

      Yep, we’ll get something but I think we can all agree Centralia down to like Woodland is where the bulk of the accumulation will be in the valley (jealous of all in Longview). I guess it’s Washington’s turn to get the goods.

    • Mark says:

      Seems about right.

  5. Welp, looks like the relocated Dome is still over me and will ensure this continues to be only a slightly snowy winter for me.

    These Pineapple Express meets Arctic Blast events typically produce our heaviest lowland snows. I saw about 2 feet from one in December 1996 (at 300 feet elevation, just north of Seattle). Chehalis got about 2 feet from one on 2012.

    So yeah, someone’s gonna really get buried.

  6. Anonymous says:

    Nam says no go. Kelso North will do well. Maybe a,couple inches as far south as the Columbia river.

    • Sapo says:

      NAM 3km shows 5-7″ metro area, 4 km shows 3-6″. It’s still a snowstorm, but yeah the 00z NAM wasn’t very good. Onto the next runs..on a side note, HRRR looks potentially snowy

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

    I believe it’s officially time for this video:

  8. john.fairplay says:

    What is the supposed source of air cold enough to make this a snow event? I have 50 degrees where I live in Beaverton and aside from an East wind event, I can’t remember an 18 degree temperature drop in less than 24 hours any time in the past.

    • flurball says:

      10 degree drop in 2 hours the other night. Different set up but don’t rule it out.

    • Jake-(Gresham near Nadaka Nature Park) says:

      1) South Wind expected to stop.
      2) Overnight temperatures will help.
      3) Precipitation rate will be exceptionally heavy (think flooding of local streams kind of rate if it were rain).
      4) A lot of cold air spilling over Vancouver Island BC into the valley West of the Cascades.
      5) First week of February (low sun angle).
      6) All of the landscape East of the Cascades into Idaho is mostly covered in snow.
      7) Computer models are struggling with all variables. Equates to rarity of situation.

    • JF says:

      1.Colder air moving down from BC and
      2. Heavy precipitation rates bring colder air to
      the surface as the warm and cool air masses
      colide.

    • Jake-(Gresham near Nadaka Nature Park) says:

      Oh dang it on number 4. Meant to type:

      A lot of cold air spilling over onto Vancouver Island BC into the valley West of the Cascades via the mountain ranges.

      What JF said. Sorry. Uh. Already started on my supply. 😛

  9. This event has “NOT GONNA HAPPEN” written all over it.

    • Scooter says:

      Excuse me but it is not an “event” until it takes place, this isn’t a punk rock concert!

    • …must be your cold fog bias talkin’… 😉

    • Mark says:

      For the metro area, I concur. But I pegg’d iur 10″ event at 3″ max, so…

      What I’d like to see is meteorologists do Theo math and make a prediction – as intgr old data… today it seems we all just look at models and just say what they kick out… but when situations like this – when the models don’t have a handle on it very well – then how about some meteorologist sleuthing and predicting. Take their best shot and run with it.

      I can only assume with the latest runs coming in a few hours Nelson will do just that. And based on the latest, I see a “stick a fork in it and call it a bust” fir the north valley. Washingtons turn for the glory this time…

  10. gggcorno says:

    So which would help improve forecasting in a situation like this?
    1. Having the Oregon coast radar station built and online?
    2. Having a network (say on a grid of every half degree latitude and longitude) of remote observation stations (including profilers) set out in the NE Pacific?

    I think #2 would probably take significantly more funding, but would certainly help with both real time analysis and with model initialization.

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

    Wind directions and temperatures across the Willamette valley:
    http://www.wrh.noaa.gov/mesowest/mwmap.php?map=pqr

    Zoomed in on PDX:
    http://www.wrh.noaa.gov/mesowest/mwmap.php?map=portland

    Source Main page:
    http://www.wrh.noaa.gov/mesowest/

  12. …the big switcheroo….my forecast is for rain showers and temps in the upper 30’s and low 40’s for this particular event 🙂 …

  13. Diana F. says:

    I just don’t see it getting cold enough here…..NE Vancouver/PDX, etc…….

    • BeaverDreams says:

      All depends on how far south that cold front sags…..it’s anyone’s guess.

    • Sapo says:

      the cooling should happen throughout the day tomorrow as heavier precipitation pulls down colder air from up above. some models indicate we could be all snow by 9 AM

  14. Boring 550' says:

    Looks like the models are trending north. Could just be splatty windshields in Portland.

    • Boring 550' says:

      I’m going to make a prediction:
      Eugene-0″
      Salem-0″
      Portland-Trace
      Vancouver-1-3″
      Kelso-12-16″
      Olympia-6-10″
      Seattle-4-7″

    • Joshua Downtown PDX says:

      NAM and GFS are. RPM is not. Per the last snowstorm, the details may not be sorted until it’s GOLU time. Little changes/differences can have huge impacts.

    • Sapo says:

      Yeah, 00z runs will be very important but most importantly is just GOLU. If the models are wrong by just a little bit we could see a huge change in who gets the most snow

    • Jake-(Gresham near Nadaka Nature Park) says:

      A rare situation West of the Cascades of where moist warm air meets cold air. I will take this kind of Winter anytime. Very curious on outputs for tonight!

    • lilfoot123 says:

      Thanks Boring! Yes 6-10 inches in Kelso/Longview! I love it but the others never so much! That would be another snow day here! I love the stuff! Snow on

  15. Lurkyloo says:

    So … is a “grocery store freak-out” warranted at this point??

  16. Diana F. says:

    The master has spoken! THANKS MARK!

  17. GTS1K' says:

    Hatches battened, Alcohol supplies renewed, Generators fueled, 4WD broken out of hibernation and warmed up to get the cobwebs (and the chipmunk nests) out. Extra gas for the G’s procured.

    If only Crapcast had more than a 4 hour backup in their box down on the corner then I’d be happier. PGE has been less than reliable this winter – 5 outages thus far – a total of 24 hours w/o power. It ain’t the worst, but it’s the worst in 15 years or so.

    Bring it!!!

    • Lurkyloo says:

      Surprisingly, I’ve had no outages this year (knock on wood). I think that’s why the storm of ’04 stands out so much for me — we were down for hours back then, though not a total of 24 hours! That would suck …

    • pappoose in scappoose says:

      Same, GTS.

    • GTS1K' says:

      Geez, I better hit the store in the AM if I’m gonna even come close…..

      …who knew?

    • pappoose in scappoose says:

      You just can’t leave some things to chance.

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

    I think this event has a ton of potential. Mark’s initial forecast was 48 degrees for a high. He then bumped it up to 50F today. Here in East county with the east wind dying you always have to shave 2 or 3 degrees off (to play it safe).

    We made it to a high of 44 degrees. That put me out of the range of the initial forecasted high by 1 degree and by the new? By 3 degrees. When I see that personally as someone who lives 10 miles from the mouth of the gorge?

    I’m thinking cold bias. Also, Mark doesn’t also bump up the high temperature and that occurs! What normally happens is I’m off Mark’s high temp. by 1 or 2 degrees in a South wind situation. So this has gotten very, very interesting. As an amateur to this my gut is telling me brace for the biggest snowstorm in 10 years. Screw work tomorrow (just called it in). My 2 cents.

  19. marinersfan85 says:

    Cold rain South of Portland tomorrow is what’s starting to look likely.

    • Sapo says:

      yeah, it really is going to be close..portland could also be cold rain and just areas north see snow, or salem north could be all snow. its really hard to say

  20. john.fairplay says:

    Great info. It’s pretty amazing how many little puzzle pieces have to fit together just right to get a significant snow event in PDX area. Another tough one.

  21. So is the NWS just hedging their bets by issuing both a Winter Storm Watch and an Areal Flood Watch? I personally prefer having a bunch of snow since it’s more visually appealing than overflowing riverbanks. We’all see tomorrow. The Super Bowl might be sidelined by this epic winter.

  22. joel294 says:

    It seems that the NWS doesn’t expect much snow for the south valley. It looks like the precipitation rates will be just as heavy in the south valley as they will be in the North valley. I’m guessing it’s a temperature thing?

  23. Alohabb says:

    Flood watch issued now.

  24. Laura Hile says:

    Seriously???

    Arg! We are going to be in school until, like, July!

    Teachers love snow days even more than students do but … yeah.

    Thanks for the information, Mark. What a winter!

  25. Sapo says:

    18z RPM says 11.3″ of snow before 1 PM Monday.

  26. Marc (Brush Prairie, WA) says:

    Summary: Expect 0″-20″ depending where you’re located in the metro.

  27. Roland Derksen says:

    This winter is confounding people north of the border as well: myself included. A couple of days earlier I predicted only a trace of snow here. What was I thinking of?? We ended up with more than 6 inches. And more to come apparently by Monday…

  28. flurball says:

    an observation made from the first December snow event I believe.

    Our RPM model and the usually reliable WRF-GFS are pathetic, showing a dusting to 1″ at best for us:

  29. Anonymous says:

    Can’t wait for TV, love your detail blog! THANKS!

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

    The RPM is brutal. I recall the March storm of 2012 and I believe the RPM was the closest model to what actually transpired. Its all about where things setup, hopefully will have clarity in the overnight runs.

  31. Scooter says:

    Seeing Super Sunday snow storm surprises some, surely statistics stumble soon.

  32. I mentioned early this winter that this season may be similar to 1968-69. It might be coming to past.

  33. janalhammer says:

    I’m perfectly happy with another snow event!

  34. JF says:

    Thanks Mark!!! That assessment was worth the wait.

  35. Jeremiah Crowell says:

    Disappointed in you Mark. We are 36 hours away and all you did was point out what the models show and punt. Where’s your snow totals forecast? C’mon bro, let’s grow a pair and make a preliminary forecast.

  36. Garron 1/3 of a mile from Hillsboro Airport says:

    Yes, a big thanks Mark. Gonna be a fun ride!

  37. Loree says:

    Thank you, Mark. You give us bad news with such clear-eyed enthusiasm. : ) Thanks for the depth and breadth – you’ve been pretty spot on this winter!

  38. Al Kohilic says:

    Mark could you please tell the city of Portland to use some damn salt if it snows

  39. High Desert Mat says:

    I hope the city gets buried.

    • Jake-(Gresham near Nadaka Nature Park) says:

      ^This. And sorry for being rude earlier (poor response on my part).

  40. Deer Is. at 750' says:

    Thanks mark

  41. Paul D says:

    Another wild ride! This winter is definitely going to be one for the record books!

  42. Sapo says:

    Interesting to see the higher res models like the NAM 3km, RPM, WRF (to some extent) and the hi res canadian model (not posted on here) give us more snow, while the lower resolution GFS and GEM give us less. Euro is in the middle. Going to be a close call!

  43. Paul D says:

    First!

%d bloggers like this: