Cooldown Begins

Finally, a bit cooler today.  After 3 days in the mid 80’s, the metro area cooled down into the upper 70’s and lower 80’s today.  Onshore gradients are not much stronger this afternoon, but I expect a reinforcing push of marine air tonight to give us a longer period of morning clouds tomorrow.

Then a very weak front moves through tomorrow night & Saturday morning.  Models have anywhere from a closed low moving right through the middle of Oregon to an open trough swinging north through Washington with this system.  Either way I think we’ll see at least measurable rain Saturday morning.  NAM and GFS at 12z both give us .05 to .10" total at PDX.

It’s a one shot deal though as ridging builds in quickly behind it for next week.

Several of you have pointed out the big trough on some maps for next weekend.  Watch out!  Its the same pattern that fools us all winter long in the GFS.  It shows a ridge retrograding and a deep trough dropping cool air south out of Canada.  Then the next run puts the ridge closer to us.  Sound familiar???  Wasn’t there always a "big cold spell" right around the corner on the GFS last winter?  So I’m ignoring that for now and keeping temperatures in the 80’s through at least Thursday, assuming the ridge will stay closer to us than models show…Mark

30 Responses to Cooldown Begins

  1. Anthony Bertolo says:

    Well, I am a very mathematical thinker, and have a natural ability to visualize and implement patterns (I have worked with AI, as well as many other kinds of computer programming). Everything has a pattern.
    I can feel that there is a pattern, and that a series of above normal snowfall/wetter winters are ahead of us for the upcoming few years. Although there is an obvious warming trend through time (with each subsequent cycle being warmer than the last), there are still cycles. I believe there are 4 layers of cycles that affect our weather.
    I could be just talking jibberish, but like I said a few times, my gut is telling me this will be a good winter, and that next winter should be even better. My gut is telling me this so strongly that I am moving back from SanDiego! 🙂 Well, who could stay away from the great NW anyway? :-p

  2. Anthony Bertolo says:

    Well, I am a very mathematical thinker, and have a natural ability to visualize and implement patterns (I have worked with AI, as well as many other kinds of computer programming). Everything has a pattern.
    I can feel that there is a pattern, and that a series of above normal snowfall/wetter winters are ahead of us for the upcoming few years. Although there is an obvious warming trend through time (with each subsequent cycle being warmer than the last), there are still cycles. I believe there are 4 layers of cycles that affect our weather.
    I could be just talking jibberish, but like I said a few times, my gut is telling me this will be a good winter, and that next winter should be even better. My gut is telling me this so strongly that I am moving back from SanDiego! 🙂 Well, who could stay away from the great NW anyway? :-p

  3. Derek Hodges says:

    *appeared* *not above*

  4. Derek Hodges says:

    My answers –
    Whatever that thing I saw on radar this morning was like a plume of moisture, though not existant that quickly apperaed and fanned out in all directions though mostly to the NE. Maybe a fire or something?
    The 12z shows a big east wind event, and with cool upper air heights. Well cool enough for not about 85 anyway. Probably modified “arctic” air but were still in summer so it warms us up.
    The 12z ECMWF shows a big trough during the same time as GFS, I actually think they are both seeing the same pattern shift giving me more confidence in it. To show how I rate east winds I look at what the GFS predicts and what we actually get. The last one had a max of East at 25 on the forecast, this one has East 31 so thats interesting to note.
    As far as the latest snow talk goes I definately not only have “a feeling” its going to be snowy at times, but also data to back it up. The atmosphere just looks like its going to be active. I currently feel December will be very high chance of snow. Probably 30-50% above normal risk. I can back that up if you wish but if not just know I have my reasons. So it may turn out to be another el nino, but the patterns we will be under, or cycles :), are not the same as in years like 04/05 which was garbage.

  5. Justin says:

    Hey Anthony, its interesting to hear your thoughts. I think you may have a point about cycles, some of the teleconnectors we have been talking about on here, PDO, PNA, EP-NP, certainly go through cycles.
    I think you may be right though about snow cycles, look here at some of the ones I’ve identified for PDX, for snowstorms included. Remember, this is just for snow, the reason why its a cycle is because even in many warm winters during ‘snow cycles’, PDX saw big snow events. Obviously things such as individual snow events don’t work in cycles, but the fact that PDX often goes through many revolving periods of snow data, dating back to since records began, I find it interesting that perhaps the Polar Jet does work itself in through constant cycles in the Northwest, probably influenced by the Pacific Decadal Oscillation. They seem to last every 5-10 years, with not more than one possible exception to the cycle possible during that period. The cycles are deemed snow-negative, snow-positive, negative meaning below normal snowfall and no 2 inch+ snow event, and positive for snowier than normal with a 2 incher, and a 3rd cycle has been deemed snow-neutral, basically just different from year to year:
    1999-2006?- Snow-negative. A fairly long cycle, and with the exception of the winter of 2003-2004, a cycle in which has seen 0 snow 2 inch+ snow events at PDX. That’s right, discounting the winter of 2003-2004, our last 2 incher at PDX was December 24, 1998. Like the major La Nina of the snow negative cycle in the 1970’s, the 1998-2001 strong La Nina did very little for snow in Portland, despite the major cooling of the Pacific.
    1992-1999- Snow-positive- Even though this phase was mostly dominated by warm events in the Pacific, and +PDO/PNA, it was very good for snow in Portland, with many 2 inch+ events. Every winter from 1992-93-1998-99 saw a 2+ inch event in Portland, with many other events totaling around 1-2 inches, or even higher unofficially.
    1992-93- December 6, 1992, December 17, 1992, December 31, 1992, January 23, 1993, February 18, 1993
    1993-94- February 24, 1994
    1994-95- December 6, 1994, February 12, 1995
    1995-96- January 27, 1996
    1996-97- November 18, 1996, December 28, 1996
    1997-98- January 11, 1998
    1982-1991- Snow neutral- Every other winter had a 2 inch+ snow event in Portland
    1977-1982- A fairly brief snow-positive cycle, with the one exception being 1980-81 when no snow fell. Again, this is interesting because this period was dominated by El Nino events and a warm Pacific.
    1973-1977- Snow-negative- Another pretty short cycle, again dominated by a cool Pacific Ocean but bad for snow in Portland. Only possible exception during this period was December 13, 1975, which had snowfall totals ranging from 1-2 inches in Portland.
    From 1949-1972 it seems harder to identify cycles, for most of the 1950’s and 1960’s were neutral, some years great and others terrible. Then from around 1900-1950 the cycles pick up again (ex. 1927-1939 snow-positive, 1939-1949 snow-negative etc.).

  6. Jesse says:

    Wow, thats a huge drop in heights between thursday and friday, but I’m gonna try to not get my hopes up, its still a week out.

  7. Jesse says:

    A hot east wind or a cool east wind Derek?

  8. Derek Hodges says:

    Actually 12z has an interesting thing toward the end. http://www.cascadeaccess.com/~mnelsen/Models/ecmwf850wsi.html Check it out.

  9. Derek Hodges says:

    Actually 12z has an interesting thing toward the end. http://www.cascadeaccess.com/~mnelsen/Models/ecmwf850wsi.html Check it out.

  10. Derek Hodges says:

    12z GFS shows a strong east wind next weekend. We could be talking marginally stronger than our last event. Something to look forward too, even if it stands a good chance of changing. lol

  11. Ryan says:

    I was looking at that sharp trough coming from central Canada into the middle of the U.S. Seems like a beefy incursion for this time of year. Otherwise it looks like a ridge building up out of California dominating our weather for most of next week.
    Summer is doing its best to roar out.

  12. Jesse says:

    Alright, I decided that I’m gonna just stop looking at the models for a little while, lol. The GFS changes every run, the 00Z shows a big trough over the Pacific Northwest late next week, the 06Z shows a huge ridge over the west coast for the next 10 days, then the 12Z shows a sharp trough diving down into Montana giving us cooler NW flow. For now I’m just gonna have to accept that whatever will be will be and that we have no idea what is going to happen outside of the next four days, if that 🙂

  13. Jesse says:

    Alright, I decided that I’m gonna just stop looking at the models for a little while, lol. The GFS changes every run, the 00Z shows a big trough over the Pacific Northwest late next week, the 06Z shows a huge ridge over the west coast for the next 10 days, then the 12Z shows a sharp trough diving down into Montana giving us cooler NW flow. For now I’m just gonna have to accept that whatever will be will be and that we have no idea what is going to happen outside of the next four days, if that 🙂

  14. Anthony Bertolo says:

    Oh yeah, seems like the latest model runs show some major ridging next week 😦 I wont be back until the end of the month.
    October is my favorite month in Portland, average high for the first is 72, and the average high for the last day of the month is 56 🙂

  15. Anthony Bertolo says:

    Most winters with a large windstorm were acccompanied by a snow event in the same winter. I remember years ago, the winter started with a big windstorm, knocking down trees and everything, and later on that winter, we had a fairly large snowstorm, 12 inches if I remember right. Seems to be similar every year we have decent snow (1993, 1995-96, 1998). This year just feels right.
    I live in San Diego right now, after being a long terms Oregon junky, I am moving back. Sunshine everyday is just too boring. I thought getting away from the rain is what I wanted, now I can’t wait to get back to it, go figure. My heart is telling me this will be a good winter, which is exactly what we need up there.
    I think the weather keeps people wholesome up there. You are forced to stay inside, you get to know people better, it really is nice.

  16. Andrew says:

    Heh, well i hope your right Anthony. One thing Portland is really overdue for is a major windstorm, as in 55-70mph wind gusts and i think we may have a chance of seeing one this wnter. As far as snow goes, it is just too hard to tell if it will be a good year or not. You just have to use your knowledge of portlands weather history and gut instincts to predict a winter forcast this far out. give it another 3 weeks or so and some more constructed outlooks should start poping up as well as people revising their forcasts.

  17. Anthony Bertolo says:

    I feel like a pattern is going on with our winters. I am not a betting man, but if I was, I would put my money on a big snow year for Portland, and the rest of the NW for that matter. Thats just what my instincts are telling me, and thus far they have never been wrong.
    Maybe someone can clearify the pattern I can’t put my finger on, and I am not talking about the twenty year cycles.

  18. Ryan says:

    Whatever was on the radar next to Salem it was gone when I loaded it up.

  19. Ryan says:

    The OCS link contradicted itself. The first half the paragraph it states many areas will see below-normal tempratures on average. Then at the end it states that it will be a mild perhaps even very-mild winter.
    Kinda makes one scratch their head.

  20. josh "the snowman" says:

    Hey guys. Here’s something totally off the wall. I read this on the farmers almanac website and was wondering if it is really true or a hoax. I’m gonna have to test this theory….:)
    Q. What is the formula to tell the temperature by crickets at night?
    A. Crickets are known as the “poor man’s thermometer.” You can determine the exact temperature by counting the number of chirps a cricket makes during a 15-second interval, then add 37 to the number to get the correct temperature in degrees Fahrenheit. If he chirps 40 times in 15 seconds, the temperature is precisely 77 degrees where the cricket is sitting. And, it never varies.

  21. Derek Hodges says:

    I can’t remember if I said this all ready or not but its looking more likely that the year may average above normal, but with a negative PDO and PNA trending negative, as well as the solar minimum, things seem like they will be in an active phase where a quick system could drop in and give us a littel snow storm, wind storm, etc. It will be interesting to see.

  22. Derek Hodges says:

    I can’t remember if I said this all ready or not but its looking more likely that the year may average above normal, but with a negative PDO and PNA trending negative, as well as the solar minimum, things seem like they will be in an active phase where a quick system could drop in and give us a littel snow storm, wind storm, etc. It will be interesting to see.

  23. Andrew says:

    Also, just thought i would post a couple of the winter forcast links that i know about for those of you who have not had a chance to look at them.
    http://www.ocs.orst.edu/Winter_06-07/teague_forecast.html
    Forecast Discussion
    for the Portland, Oregon area
    The overall call for this winter is for slightly above normal temperatures and below normal precipitation. The first half of the winter is expected to be closer to normal than the second half, with January being projected as the best opportunity for cooler than normal conditions.
    Snow
    In any given year, the climatological chance for seeing a significant low elevation snow event in the Willamette Valley is about 50%. This outlook calls for an increased probability for seeing lowland snow, particularly in the first half of winter. To take it a step farther, data suggests that if the ENSO regions see slightly less warming than what was experienced in most of the analog seasons, the probability for lowland snow is quite high.
    Analog Year Notes
    While analog years were not selected by the criteria of an assumed development of El Nino, 6 out of 7 the seasons were in fact El Nino’s – mainly of the weak variety.
    http://www.ocs.orst.edu/Winter_06-07/steve_forecast.html
    Synopsis
    All in all this winter should bring a little bit of everything as long as the current pattern holds. If SST’s warm to levels sufficient for El Nino, the result may be drier and slightly warmer than is forecasted here. Stay tuned!
    http://www.ocs.orst.edu/Winter_06-07/forecast.html
    General Weather Forecast and Report: Our study of solar activity suggests that a weak El Nino will develop this winter, resulting in below-normal temperatures, on average, in much of the country. Snowfall will be above normal in most areas, especially in the Upper Midwest and Heartland. But, with the Atlantic warmer than normal (and getting warmer still) and the Pacific also relatively warm, most regions will have at least one mild month. (If the El Nino fails to develop as expected, the very cold periods will be brief and most of the country will experience a mild winter overall—perhaps even a very mild winter.)
    The NOAA has a new service they are testing out right now as well, but i can’t find the link for it 😦 . If anyone has any more forcasts links please post them, i love to hear everyones opinions.

  24. Andrew says:

    I like their forcast 🙂 , even though there is no way of knowing how close it is. Anyone know their forcast history?
    Pacific Northwest Summary: Winter will be a bit colder than normal, on average, with above-normal snowfall. Precipitation will be below normal in Washington and above normal in Oregon and California. The heaviest snow will fall in mid- to late February, with other snowfalls in mid-November, early to mid-December, and early to mid-January. The stormiest periods will be in early and mid-November, mid-December, and mid-March. The coldest temperatures will be in early December, mid-January, and mid-February.

  25. Derek Hodges says:

    My own experience with that is just yesterday the 12z gave us a pretty good trough coming in here on Saturday. Then the 18z nearly killed it. Then the 00z brought it back and tonight to an extent the 18z agrees with the other runs, and contradicts itself from yesterday.

  26. Justin says:

    Well in my experience, we’re probably both right. The 18z always seems drastically different from the previous several runs and sometimes the several runs that follow it. Its a double edged sword, the fact that it always seems so cooky means that it is at times the first to catch up on a big change, usually pointing towards ‘less extreme’ than the 12z and 00z. But then just as many times it seems to almost immediately reject its own ideas and go back to its previous thoughts. The fact that its always so far to one extreme or another makes me think of it as the crackpot of the forecasting models, whereas the other runs always seem more temperate, so to speak. Not always wrong by any means, just always very iffy.

  27. Mark says:

    I’ve got to disagree on the 18z thing. Several times the GFS has been the last to jump on the bandwagon (compared to ECMWF) and suddenly the 18z is the first run to show it. Maybe that was by chance since you get 4 runs a day and each one shows change at times.

  28. Justin says:

    Hey Mark, a nice early blog today. I agree with your thinking for now, lord knows I’ve seen my fair share of phantom mega troughs and they have a way of decieving everyone until the last minute.
    However, in the trough’s defense, the 18z GFS is largely known as the crackpot of forecasting model runs, seeing as its always drastically different from the 12z and 00z run that follows.

  29. Derek Hodges says:

    I think the 18z already weakens it a little bit already. Well its to far away though to be riding each model run for now. The trough coming in this weekend should give us a nice little break.

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