A Colder Week Ahead!

We may have the first widespread cold period since mid December coming for next week across the Pacific Northwest.  Models have been advertising a cool northerly flow for next week for quite a few days, and there have been hints of an “arctic intrusion” of some sort too.  What’s the difference between that and an arctic blast?  Not sure, but it doesn’t look nearly as cold as what we saw back in December.  And this time, as of tonight at least, there doesn’t appear to be any moisture associated with the cooler air for snow.

The 00z GFS and 00z ECMWF both agree on a gradually cooling air mass from Sunday onward.  The ECMWF is especially aggressive with 850mb temps down around -10 at 850mb over our area.  At the same time we get gusty east wind through the Gorge…brrr, if so winter isn’t done yet!  Take a look at the strong easterly pressure gradient on the ECMWF too:


I lowered the 7Day forecast high temps into the 30s as a result.  If it was November or December and it hadn’t been cold yet this season, I’d say it’s time to wrap the pipes etc…  But we’re still in winter and there’s nothing to “prepare for”.

Here is the 00z GFS ensemble chart:


and the 12z ECMWF ensemble chart:


They both seem to be a little on the cold side; the blue lines are the operational runs we get the maps and output from.  The red is the average of all the ensemble members.  There is a clear signal that once we get to about next weekend we go to a wetter westerly flow and temps back around normal.  Since it’ll be mid-February by that time, my gut feeling then is that next week will be the last chance for a many-days-long cold spell this season.

Other than the impending colder weather, the theme for this winter remains the same for the next 8+ days…DRY.

Chief Meteorologist Mark Nelsen

90 Responses to A Colder Week Ahead!

  1. JohnD says:

    Where the heck is Rob when we REALLY need him!

  2. Taylor says:

    Is this arctic blast going to potentially rival the one from December? If so bring it on! Just not looking forward to bundling up lol

  3. Rob - Southeast Portland says:

    VERY cold 00z runs tonight!

    First, 00z GEM was just incredibly cold.
    00z GEM 850mb temp loop
    Officially the coldest I’ve ever seen!
    -20c to -25c PDX Holy ………

    Next, 00z GFS Ensembles. Coldest yet. Coldest mean temp yet! Down to -14.5c and lots of members -15c or colder!

    What will 00z EURO show? It’s running now….

  4. Jason Hougak says:

    And what’s this the 16 day GFS is now showing precipitation on Sat 2/8. Just a few hours ago it was dry. Things are looking up for snow! 🙂
    Check out those temperatures

  5. Jason Hougak says:

    10 day GFS showing 850mb temps.
    Core polar air shifts from central Canada west into Alaska, sw Alaska, Yukon, and British Columbia. This could get interesting if jet stream becomes a NW flow out of the gulf carrying cold air out over the Pacific. Perfect ingredients for Cascade snowpack! I’m a record snow will be in store for us by sometime next weekend.

  6. Model Rider says:

    Okay I’ll go first, the 00z has the trend continuing. Looks almost identical to the 12z except it looks like there’s a little bit more precip on Monday.

  7. alohabb says:

    I remember about 30? years ago having a snowstorm around Feb 21st or so because my family got stuck at our house during a b-day party.

  8. alohabb says:

    What the… The highs for mid week wont even break out of the 20’s!!!! Clear and cold!

  9. Rob - Southeast Portland says:

    4:50 PM Update
    The system for Monday can already be see up in Yukon.

    You can see on IR Loop it’s progressing southward slowly. Where exactly this tracks will play a role in how much precip we see, or if it’s largely dry. If it slides a bit offshore it could pick up a bit of moisture. If it tracks further inland things should be fairly dry.

    Also, I personally am not ruling out the remote chance for a surprise dusting of snow to maybe a quick 1″ with this, but everything has to come together just right. This system as it heads south is also what will dig out the arctic trough over western Washington and Oregon bringing very cold air into the area Tuesday – Saturday(possibly beyond?). So all of the pieces are in place and the pattern progression can be seen in real-time on IR Loop instead of merely relying on the models to see the what and when. I really like that you can track things now with the eye and not rely solely on stupid computers.

    • Model Rider says:

      Thanks for the posts Rob. We all cant wait for the other posts to come tonight after each model run. Bring on the frigid temps!!

  10. Rob - Southeast Portland says:

    18z GFS Ensembles. Operational was the outlier and warmer than the mean through February 9th. The usual increasing spread amongst ensemble members increases beyond day 9-10.

  11. vernonia1 says:

    ODOT: Valley, No. Coast: OR 20 is closed in both directions just east of Santiam Pass near Suttle Lake Loop following a two vehicle crash involving major injuries. Law enforcement has closed the highway to conduct a crash investigation and reconstruction. This will likely be a long closure. There are no easy detours so motorists should avoid the area, use an alternative route or expect long delays

  12. Sapo says:

    Highs in the 40s next week on KGW’s forecast? What weather models do they use…

  13. Model Rider says:

    Great, it will be below zero again over here and if we get a cloudy day highs may stay in the single digits again. Hmmmm…better get some precip with it this time around. Managed a mere 4 inches total with the last arctic blast and a temp of -27.

  14. Taylor says:

    Have we ever had a February snowstorm? Regardless looks like it we will be getting cold if nothing else. But, I want snow so hoping for that as we got barely anything in December with Southern Oregon getting hit hard.

    • Aloha Rainshadow says:

      Have we ever had a FEBRUARY SNOWSTORM????????? Oh man…Wait til Steve Pierce sees this lol

    • Aloha Rainshadow says:

      Ok, I’ll bite…

      Let’s just say, we’ve got HAMMERED in February many o’times and we are actually due…

    • Taylor says:

      You know we will see. On the 7 day forecasts it’s showing no moisture which is concerning to snow chances.

    • Sapo says:

      Actually Taylor models have predicted showers possible on Monday and that is definitely in the forecast, plus the overrunning chance is actually beyond the forecast.

    • Taylor says:

      Yeah I’m just trying not to get my hopes up too much. We’ve been burned over and over again.

    • Jake-(Gresham) says:

      Nope Taylor you’re right the moisture isn’t yet in the picture but people are just excited because the cold is coming so we’re all hoping this turns out to be a classic February snowstorm. 🙂

    • prairiedog says:

      What year was the Valentines snow storm? It happened just around that date where almost a foot of wet snow fell in and around the metro area. It snowed all day and the temp stayed at 33f. I had 11″ on my deck. It was around ’92-93 I think.

    • Jason Hougak says:

      Come on… go offshore pickup some good Pacific moisture and swing in the good stuff.

  15. BoringOregon says:

    Wow, going to be only in the low 30’s for the high in Portland. Dang means its going to be cold out here for the highs and low temps. Has any one saw the thing about the “Snow that does not melt” back east?

  16. Randy says:

    Wow. 7 day has highs in the 20’s and low 30’s now.

  17. Jason Hougak says:

    February 10th snowstorm. It’s about time!!!

  18. Sapo says:

    12z GFS pretty good, showing a much slower warmup and some overrunning precipitation of the exit of the cold air. Also, ensemble mean pretty cold for awhile, lots of members extending the cold air. 12z ECMWF even colder, also slightly slowing down the exit of the cold air. 12z GEM has decent precipitation through the 5th for a few inches of snow. Come on snow!

  19. Marcustheweathernut says:

    Wow according to the 18z we are locked in the cold for a while!!! We may actually see some snow before we get out of this cold!!!

  20. W7ENK says:

    10 days ago, the models showed an arctic blast with snow beginning in 10 days, which would be… today.

    Every year for as long as I can remember, I’ve wished for snow on this day, 1/31. I did a little historical digging, looking up the weather for 1/31, going back 35 years.

    In that time, not one single snowflake has fallen in Portland on the 31st of January. In 1979, there was 1 inch of snow on the ground, but it was sunny with East winds, and that snow had been there for 3 days already. The following year, PDX received 0.12″ of freezing rain, but 1980 was the last time PDX saw frozen precip of any kind on 1/31. In fact, PDX hasn’t had a temperature below freezing on this day in 18 years, not since 1996.

    Again, as per usual, I wished for snow on this day. With the models showing snow 10 days ago I was slightly hopeful, but alas, I guess I should have known better…

    Just 8760 hours ’til the next one!

  21. Jake-(Gresham) says:

    Well 7-day forecast is showing the cold temperatures into the 30’s now so I’d say the cold is on it’s way. I really hope however that this doesn’t end up being just a regular dry arctic outbreak. :/

  22. paulbeugene says:

    Train has left the station. It looks cold once again, an earlier version of late February arctic outbreak we had a few years ago.
    850mb temps to -15c or colder suggests temps struggling to reach 30F in day with lows 12-20F.
    This is a back door arctic blast, favoring Oregon over western Washington for cold temperatures and possibility of snow (light amounts). At this point see PDX having 1/2-1″ at most, 1-3″ elsewhere in valley if lucky, at onset of cold outbreak. Eugene used up all the lucky last December, so we may just get a skiff.
    There seems to be reason to believe that transition out of cold would white and not silver.

    • prairiedog says:

      Do you see an arctic boundary that would be an SOWT event? That seems to be the only hope for any snow for the onset at least how I see it. Otherwise it is indeed a backdoor event and they tend to be pretty dry.

    • gidrons says:

      I just checked the Euro and thought to myself “If this doesn’t bring Paul back, nothing will”. I log on to the blog and sure enough, Paul is back.

      Its decision time for Mark.

  23. WEATHERDAN says:

    Sunny day here in Salem for my 60th birthday. 47 and partly sunny with a good South wind at noon. May hit 50 today but this will probably be the last time for that for quite a few days. Let’s hope for some snow.

  24. DEL X V says:

    I remember looking out the window on Sunday , February 1, 1937, in east Portland and seeing snow drifts about 18 inches high. The next day the electric Trolleys were snow bound around 72nd and Foster Rd. Plenty of snow can happen in early Feb.

    • JohnD says:

      I remember my Dad talking about that. Awesome
      memories. Thanks for sharing! And here’s
      pulling for a history repeat!

  25. Aloha Rainshadow says:

    Surprised Paul B hasn’t chimed in…

  26. Rob - Southeast Portland says:

    12z EURO very cold -17c 850mb temps it looks like.

  27. Poolsidemike says:

    Ha! A week from tomorrow I will be taking part in the Polar Plunge…a benefit for Special Olympics Oregon….thousands of crazy folks will be taking a dip into the Columbia River out at Broughton Beach (by the airport) to help raise money for charity. In a sick, twisted way, the prospects of very cold, east winds, etc. have me kind of excited! Bring it on, Mother Nature!

  28. Tomas W. says:

    SMH Cold Feb spike my home heating bill.

  29. Greg Carstens says:

    Great! My mom will be coming back from her trip to Australia and New Zealand after enjoying summer down there and will fly into the next ice age beginning here in the Northern Hemisphere.

  30. Rob - Southeast Portland says:

    12z GFS Ensembles. Mean around -13c, but notice we stay at -6c or colder now THROUGH February 12th. Also, note how many more cold members there are beyond day 10. This MIGHT become a much longer event(perhaps snowy!)

  31. Rob - Southeast Portland says:

    Right now this looks COLDER than December’s blast. 925mb temps on the WRF are down to -16c by Thursday AM. CRAZY! it may peak -18c Friday-Saturday.

  32. schmit44 says:

    Deadline to enter will be Feb 3

  33. Aloha Rainshadow says:

    AS WE ALWAYS SAY, we need cold here first, that’s our hardest ingredient to get, then we go from there. Remember, smaller scale features dropping down from the north aren’t always picked up until a few days ahead. I’d say just be happy we are getting a very rare event with 2 arctic blasts possible in one winter…then we’ll see what materializes, moisture-wise, from there.

  34. Rob - Southeast Portland says:

    12z GFS very cold. 850mb near -15c, thickness near 511. Excellent potential for snow/ice storm after day 7.

    12z GEM even colder. 850mb near -17c, thickness near 507. Incredible.

  35. Jason Hougak says:

    Got SNOW?

  36. Sapo says:

    All of the models have pretty good agreement on the cold air. For the precipitation, the GEM has a pretty decent amount of precipitation on the night of the 3rd, and the GFS has a weak system. Maybe some snow there? Also, the timing of the precipitation as the cold air moves off will be interesting to see if maybe we can get some snow then. Anyway, looks interesting!

  37. Rob - Southeast Portland says:

    With the improved model consistency and agreement amongst the GEM/EURO/GFS through day 7-8 it’s hard to not jump on board, hard to note bite at this colder/arctic blast solution. If 12z runs later this morning continue the theme it’s starting to look very promising.

  38. Rob - Southeast Portland says:

    6z GFS looks good (for cold) 850mb down to -13c, thickness 514. There is good potential for either a brief overrunning event or a something more significant as we transition out of the modified arctic air mass into a moister westerly flow.

    ***WOW. 6z GFS Ensembles alert! MUCH COLDER!
    Portland – The mean temp is down to -13c with several members -15c or colder! Remains at -5c until February 9th. Beyond this point the mean warms, but there are a few cold members which keep things interesting and perhaps cannot rule out a prolonged cold snap.

  39. schmit44 says:

    1/30/2014 Oregon (All) Temperature Summary

    High:57 at EW3367 Coos Bay( 98 ft)
    Low: 45 at LINCON Lincoln C(187 ft) & W7KKE-3 Road’s E(89 ft)

    High:20 at Mount Hood Meado(6601 ft)
    Low: 9 at CRANE PRAIRIE (5500 ft ) & Baker Valley (3420 ft ) & MT. HOWARD (7910 ft ) & ANEROID LAKE #2 (7300 ft )

    Largest Diurnal Change: 28 degrees
    North Powder (I- (39/11 ) (3273 ft )
    CRANE PRAIRIE (37/9) (5500 ft)

    Heaviest Rainfall:
    1.17″ at CW2654 Corbett(1050ft)
    1.10″ at BLAZED ALDER(3650ft)

  40. Ben T says:

    Its gonna snow! I hope.

  41. Ron says:

    It was 60degrees and sunny at the coast last weekend and I mowed the lawn for the first time since September. We had a good shot of snow in December, and the smell of fresh cut grass made me forget all about wanting more.

    • Mike Holmes says:

      Good shot of snow in December! Dude it was NOT a shot of snow. A shot of snow would’ve been 3 inches or more! That snow in December isn’t even worthy of being called anything!

    • Jason Hougak says:

      That shot of snow depended on where you lived… The Eugene area got around 8″ of snow. Sure we missed it up here but no everyone!

  42. Benjamin (West Salem) says:

    Thanks Mark for posting!

    I like that you said “many-days-long cold spell this season.” March 2012 for us in the valley comes close to breaking that “rule.”

    • I think the reason March 2012 broke the “Winter Fork” is that you had several little snow events, plus the big Salem/Eugene storm, after what was otherwise an extremely boring winter. So most of the weather “action” that season came in March, which is very unusual.

    • Benjamin (West Salem) says:

      Very True Karl. That’s the only time I ever remember having a steady snowfall in March. For once it wasn’t just one of those cold core showers that moved through at just the right time only to drop a slushy dusting. Instead, this was for some areas above 1000′ almost 48 hours of continuous snow. Even for me at an elevation of 225′ we had almost 4 inches that actually stuck. I wont expect that to ever happen again… at least in March! 😉

  43. Trish Lilley says:


  44. W7ENK says:

    Where’s the snow??

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