Past Events Can Help Current Forecasts

1pm Tuesday Monday…

Just a quick note as I’m making my forecast.  Take a look at the blog post from the freezing rain event on March 1st.  The one where the WRF-GFS was forecasting snow in the cool east wind part of the metro area?  It ended up being all rain in the metro area except freezing rain east of I-205 (not on roads).  Freezing rain at my place at the west end of the Gorge and ice pellets from Bridal Veil east.  This was the snow forecast map:


Look familiar to those of you checking out all the maps today?

Models were too cold that time around and it’s real interesting to read past thoughts as the event approached.  Take a look here:

40 Responses to Past Events Can Help Current Forecasts

  1. Jason Hougak says:

    This site has awesome history about record cold Oregon winters.

  2. Tyler Mode says:

    Wind is playing with the temp here. It was down to 39 at 7:30 with no wind. Now it’s 43 with the wind picking back up.

  3. Jason Hougak says:

    Coldest night so far with a balmy 36F and a light east wind making it the first chilly night getting firewood in the barn. I’m so ready for a deep winters snowstorm. They hype over this has got my wheels turning if we will ever experience a Jan. 1950 winter again.

    • Hal In Aims says:

      Wasn’t very old….but do remember the water in the toilet being frozen and being cold… do not need that again…

    • SW says:

      If we take a look at how many times 1949-1950 has happened in history (recorded or speculated), I would say the odd’s are next to 0… but not 0.


  4. Jason Hougak says:

    Nome, Alaska 36F, Barrow, Alaska 21F, while Great Falls, Montana is 3F. Polar arctic air plunge, who’s in?
    Day 10 of 10 day GFS shows another arctic reload coming out of Yukon and NW territories.

    High wind warning for foothills, driving back home looking at all the old growth fir trees towering 200′ plus around Eagle Fern Park. With gusts in the 60 mph range I wonder how many will fall in the next couple days.

  5. Tyler Mode says:

    39 here in Battle Ground.

  6. paulbeugene says:

    It is worth mentioning that, aside from perceived delay in progression of the arctic front and attendant E/NE winds, the models have been fairly consistent in the past 72 hours, at least for the short term.

    MOS numerical output for lows tonight and Tuesday night for the Willamette Valley have been trending down. 20-25 for lows in Salem/Corvallis/Eugene tomorrow night possible if winds slack off.

    Would be nice to sneak a 19F into the books in case we don’t get another chance this winter…you never know. Probably won’t come close to the records set back in 1978.

    As for the gorge winds, expect that they should kick in by 4-6am tomorrow morning.

  7. jimbo says:

    This post is as 1 pm Tues? Mark are you across the dateline somewhere?

  8. JERAT416 says:

    Bye bye leaves on trees! This should be interesting. I live in Beaverton but work a stone’s throw of I-205.

    • Phil says:

      Some Forest Grove trees still 100% full of green leaves with a freeze on the way. I have not seen this much of a delayed fall combined with early winter occur in my 27 years in Oregon.

  9. Comparing current Meosanalysis to 12z WRF to see where we’re at with progression and movement of arctic air…… It’s still delayed. WRF at 7:00 PM had 850s -12c to -14c into northeast corner of Washington…. but it’s only delayed due to the slow movement of the dome of high pressure and system in Saskatchewan. When I look at the 850s 4hr progression I see shows a sharp abrupt shift west with arctic air now.

  10. For example:
    Currently as of 4 PM the TTD-DLS gradient is around -2mb. 12z WRF had it modeled around -3mb at 4 PM. The pressure reading at Spokane is currently 1021.8mb. WRF had it modeled to be 1025-1026mb. 850mb temps over Spokane is currently -4c and modeled to be -5c. So, it seems there is a bit of a delay with the coldest air flooding into eastern Washington. Is this going to be a big deal? Unsure right now, but if we were to see this continue the next 6-8 hours with little increase in gradients or cold air not building into eastern Washington, then that could be another story. It’s just something to keep an eye on.

    • From reading the Spokane AFD it sounds like things are on schedule with the arctic air tonight-tomorrow and any delay would be due to the low in southern Saskatchewan moving southeast into the plains and one remaining wave accompanying it to move through Idaho. I can see it on IR Loop

  11. Benjamin (West Salem) says:

    I think this could end up like March 2014 in that the cold air could be overestimated by models.

    However, a few differences that are working in our favor this time for wintery precip compared to March 14 is that this time we should have a better DP/temp spread for better wet bulb. We will have steadier precip for helping the wet bulb process. March we only had a short period of time where east winds were blowing. During the March “event” we had southerly breezes by Sunday morning up the valley. This time it looks like east or Northeast winds will be blowing from tonight all the way into Friday morning.

    Lastly; although it’s very early in the winter season to have real deep and cold arctic air to work with when compared to March, we will have a weaker and lower sun angle helping us out. March 2nd is only 3 weeks away from the equinox. We are several weeks closer to the winter solstice this time…..

  12. Jake-(Gresham) says:

    The thing I’m sitting on is when does the cold air arrive and afterward the moisture. The computer models I’ve noted tend to underestimate how difficult it is for the cold air to travel over the mountain ranges before reaching the Columbia basin.

  13. Now we sit and wait. If the models are correct we’re going to see a quite a bad east wind storm. Everything is predicated however on just that, the models being correct with their handling of the cold air, depth of it, when it floods into eastern Washington/Columbia Basin, and the offshore PDX-DLS/OTH-GEG gradients responding to this. We’ll see how things develop, but unfortunately there are few guarantees in weather.

  14. This is only the 3rd time in my life I’ve seen a High Wind Warning for east winds. Will it verify? If models are correct, yes, and it could be very memorable not just due to the sheer force and magnitude, but the long duration lasting 24 hours or so. With a projected PDX-DLS of -11 to -13mb, OTH-GEG of -24 to -27mb, the strongest 4km Time Height we’ve ever seen, a stable layer at 750-800mb with flow reversal on the 12z MM5-NAM/4km WRF, this is really quite possible.

  15. W7ENK says:

    NWS going all in…

    216 PM PST MON NOV 10 2014

  16. High Desert Mat says:

    But Mark also go back and look at the some of your blog posts from early February of this year. You say it yourself that models weren’t handling the situation good at all. Especially the wrf and the rpm.

    • marinersfan85 says:

      February also wasn’t a “marginal” event. Cold air was plenty and plenty deep enough. It’s not like we’re looking at temps in the teens with plenty of moisture.

  17. WhiteEagle - Garden Home/SW Portland says:

    Mark, I think you nailed it with the headline. While I don’t always believe in analogs, either, I believe there are important lessons to be learned from past events.

    How similar was the setup March 1 versus this week? How strong were the east winds? What were the gradients? How cold was the air on the east side and how strong was the push of maritime air moving inland? All interesting things to look at.

    I believe that either way, there is going to be a fine line in this event between whether the metro sees wintry precip or not. Surprise!! 😛

    I think we will all probably get the forecast wrong to some extent, because this is a rare early season event. And bottom line, we’ll all learn from it for the next time this type of scenario tries to happen.

  18. W7ENK says:

    I’m not totally sold on the idea of analogs. They never seem to pan out in our favor.

  19. GTS1K' says:

    Ice pellets it is!

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