Record Dry December

We’re halfway through December, and we’ve seen all of .06″ rainfall so far here in Portland.  That’s the driest first half of the month we’ve ever seen here!

The next closest was December 1976 when the first 15 days only yielded .32″

Now discuss amongst yourselves…

42 Responses to Record Dry December

  1. TAGinGresham says:

    So is it safe to say that a white Christmas isn’t in the cards for this year? I hope all of this “mild” weather leads to “wild” weather in January!

    What is the name of the facebook group?

    Enjoy your vacation Mark!

  2. Yawn Yawn…..I felt this way in December 1976 and hoped that things would get better. They didn’t…..

    Hope this year that’s not going to be true…

    41 even degrees….

  3. PaulB/Eugene says:

    Looking drier through end of Dec. on GFS ensemble mean 00z…the spirit of ’76. Canadian not much different. ECMWF dry too. Time to reboot.

  4. Karl Bonner says:

    If we’re going to have an ongoing period of dry weather and Columbia Basin cold pooling, I’d prefer if we “really went for it” and got some serious 2005-esque coldness to the lower-level airmass! Now THAT was a fascinating pattern to see unfold. It’s a bit unfortunate I was in Eugene at the time it happened, as it must have been VERY interesting to witness first-hand as a weather geek!

    It wasn’t quite arctic air, but it definitely had some strong polar chill. We often use 850mb temps to extrapolate downward and see what temperatures would be like near sea level were there no inversion setup, but when you get a cold pool up to 3,000-4,000+ feet deep, the cold pool consists of more than 10% of the total mass of air in the vertical air column all the way to the top of the atmosphere. The fun thing is to take the lowland temps and extrapolate UP to 850mb by normal lapse rate to see what you get. By my estimates, in 2005 the bottom several thousand feet of air east of the Cascades was as cold as a conventional arctic airmass with 850 temps around -14 to -16 degrees C! Not frigid, but definitely very nippy weather. A more conventional cold airmass with lots of clear skies and the same 850s might give us highs in the low 30s and lows in the teens – definitely at least subarctic air!

    Of course we can easily fall prey to wishcasting, even when it comes to “homegrown” polar airmasses. The reality is we are in the middle latitudes and that imposes realistic limits on how far such a process can be expected to go. But the 2005 tale at least proves that this cold pool phenomenon is capable of progressing to a remarkably advanced stage, given ideal conditions and enough time.

  5. Brenda E Vancouver says:

    So I have a idea, but it’s a little “out there”. When I was a kid I used to wonder about the seasons and how sometimes the seasons wouldn’t seem to match the months they were “supposed” to be in.

    I’m far from being an expert, I can barley understand the weather models 🙂 but I wondered; what would the result be if we took the weather data from the past year and moved the calendar back or forth a month or two. Would our seasons line up then? (told you it was wacky)

    I found this site that talks about old calenders:

    Here’s a paragraph that caught my eye.

    In Persia under the Sassanids, and in Armenia and Cappadocia the official system of time-reckoning was twelve months of 30 days followed by five more days at the end of the year. However, Arabian astronomers said the Sassanian year of twelve 30-day months was adjusted to the seasons by intercalating a month every 120 years.

    My issue with this idea is that the tilt of the earth messes everything up. So my even crazier thought was this: I wonder when they last calculated the turn and tilt of the earth, the distance from the sun and are their calculations off?


    • W7ENK says:

      Leap year (February 29th) accounts for all that in today’s modern (Gregorian) calendar, though it’s still not perfect, which is why we have a “leap-second” about every 500 days. Leap year is also skipped at a set interval, most recently in the year 2000.

      Through friction, the Earth’s rotation is naturally slowing down, so that adds a near-constant variable into the mix – back in the days of the dinosaurs, a day was roughly 22-1/2 hours long.

      Additionally, the Indonesian earthquake in 2004, and the Japan earthquake last March actually accelerated the Earth’s rotation by a small but measurable margin, which needed to be calculated and then factored into the Universal Time Coordinate.

    • Karl Bonner says:

      I like the eight-season calendar system the best, where you divide the year up into about 6-7 week periods instead of 13 weeks. It fully represents some of the more subtle elements of our seasonal cycle.

  6. The 00z GFS, GFS Ensembles, and 00z GEM just basically…Well, I’m not even going to finish this…let’s just say Mark got his winter weather for the winter, hahahahaha

    • Karl Bonner says:

      Are you saying spring is here? Even yours truly doesn’t go quite THAT far with his wishcasting! 😛

    • Mark Nelsen says:

      Nice to see you on here again Ryan, but I have to admit that Facebook group sure is convenient for weather chit-chat as well.

    • bgb41 says:

      Mark, can’t tell you how happy we all are to have you commenting more frequently in the facebook group. I really appreciate it.

    • Thanks Mark, it’s hard to decipher the high school BS from the remarkably grand insight from others. I think you do a great job at quarrying the aforementioned…problem is, you can’t say what you are thinking on your “work website.” I pop in all the time to hear what you are thinking simply because I believe you are still the best PDX forecaster out there…and I always lean on your forecast. Second to Steve Pierce of course…hahahahahaha…j/k…or am I? 🙂 I shouldn’t blow up his ego like that should I?

  7. For all those steelhead fishermen (and I’m one)…..

  8. Dave in SW PDX (235') says:

    Don’t know if there are any other Wilco fans frequenting the Fox12 Weather Blog, but if so, here’s Jeff Tweedy on WGN this morning with the 7-day forecast:

    Currently 43.1° here; 0.12″ of precip for the month so far at my house.

  9. Even if this ridge breaks…for those snow and cold lovers, you’re going to have to LOVE the inversion a bit more as you won’t get a “REAL” cold setup until at least early/mid January…at least. 00z takes away the hopes for next week. We’ll see if the Euro/GEM/Ensembles bring up anything to talk about.
    To give hope: Models do eventually washout this ridge in the long term. Hate to say that as they did a week ago as well but the elongated high in the EPAC shows a retro in early January…how amplified that is if it actually occurs is the question. Keep your head up, late January and Early February is my thinking right now…and a bit more into my thinking…it could be a long cold period and well worth the wait………I hope.

    • Ryan (Walnut Grove) says:

      Alas, the models have been washing out the ridge I the long term since it setup. Only a couple small systems have been capable enough to override it. The it pulls out some sort of ridge steroid and strengthens.

      One day it will break.

  10. oldwxwatcher says:

    Tom Skilling on WGN in Chicago has been talking a lot about how wet this month, and others, have been in that area. They’re sitting at 49 inches of precip for the year so far and no snow of consequence as yet this season. Everyone’s getting wacky weather it seems.

  11. El Donut says:

    Payback for this is gonna’ last thru November: The Fall without a Spring!

  12. I’m going with the latest model. The ol’ 8 ball 😉

  13. Low so far this winter only 29.0F. Citrus has been outside in the open. With no arctic air yet, no need to push into the garage. Winter has been most unimpressive thus far… 00z GFS may have some changes in store?

    • Nope. Permaridge 2011 holds firm. Shows the value of long term forecasting (la Nina bust). Long term forecasting = witchcraft = farmers almanac = waste of supercomputer time. You can’t model random to the third power

  14. Doppler Dave (NE Portland) says:

    Even with a record dry first half of December, it is looking like the pattern is about to change and we will have a fairly wet second half of the month in my opinion. I’m also watching next Wednesday as a possible first snow of some sort to the valley floor. This will likely flare up some discussion. 🙂

    • Dave, IMO, this will be the same as last time, typical December setup…if you are in the right spot at the right time at sea level, you may see some in the air, or maybe stick but nothing of substance. I may just be a bit jaded but it seems the same as our typical setup, most snow 1000 feet or above and those below see maybe some flakes around.

  15. Holding at 42 here. Only dropped to 35 last night. This will be my first day that hasn’t dropped below freezing this month.

  16. W7ENK says:

    0.03″ yesterday, and another 0.05″ today = a grand total of 0.08″ for the whole month of December so far…

    • Garron Beaverton says:

      The river at the bottom of the model riding cliff is running pretty low! 0.04″ in the bottom of the rain bucket here for the month.

  17. Ended up with .15″ of rain during the day today. Up to a whopping .27″ for the month now! High of 42.4 today after a morning low of 35.4. Currently 38.1 so it looks doubtful that I will hit freezing today. Thus my streak of sub-freezing lows will end at 17 days.

  18. Any drier and Salesky’s toupee is going to become a tumbleweed!

  19. Joshua in Lake Oswego says:

    Me thinks we will have a wet last week and the goods will be delivered later in the winter.

  20. bgb41 says:

    This is the 3 week ridge we needed back in May/June. Too bad we are getting it now.

    • Karl Bonner says:

      How about February 15 – March 15, or better yet, continue into April with a few minor disruptions?

    • Mark Nelsen says:

      Yeah, don’t you think we could get this pattern ANYTIME other than mid November through mid February instead????

    • Karl Bonner says:

      Back in late spring everyone seemed to be complaining about the Worst Spring and early Summer “EVER!!!!”, so anyway, what were some of the warmest and driest springs and what kind of short-term weather cycles (AO, ENSO, etc.) on hand?

      For “false” (early) springs I got 2010, 2005, 1995 and I think 1992, in the past 20 years – but the only consistently warm spring in recent years that I recall was in 2004. Are we in an ongoing unlucky scenario with respect to nice spring weather? And what about the September-October period? (Imagine if the dry weather of late October and early November had come in early to mid October instead!)

  21. Not good. 76/77 was horrible from start to finish. The worst. The lousiest. The foggiest. And that was an El Nino winter. We don’t want dat!

  22. Sean (Canby) says:

    first! .. but tired of the boring

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