BTRWx

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Posts posted by BTRWx


  1. 1 hour ago, ORH_wxman said:

    You definitely have to be careful looking at the just the heights nowadays....you can have a lot of above normal heights in the arctic but it doesn't necessarily mean blocking...it just means the arctic is warm. Often that means there's blocking, but there's plenty of instances (esp in the post-2005 world) where the high heights up there are just a result of warm temps up through the column...a similar pattern in the 1970s would produce no "blocking".

    I definitely would like to see an example please.


  2. On 9/20/2017 at 6:56 PM, Bob Chill said:

    I think I figured out why the main trop thread gets on my nerves so much. It seems that some believe the more they post the higher their cred or expertise is. But in reality they simply talk too much. Pretty much the same as a good bs artist. 

    :o


  3. 6 minutes ago, 09-10 analogy said:

    Ugh. I can't even blame this one on a typo. I remember the day and the event so clearly, but I can't get the date frickin' right. 

    The 21st has so much significance to me -- it's my birthday date, my anniversary date, the date my daughter was born (not all the same month of course) -- so I guess that's my excuse.    

    Happy birthday and/or Anniversary to you and/or whoever!


  4. 4 minutes ago, mitchnick said:

    Let me wrap up any sane winter forecast for this area this year as follows: If we fail to get sufficient blocking, we're screwed....period. If we get sufficient blocking to get us in the game, we're gunna still need a lot of luck, and we won't know how or what kind of luck until each event shows itself.

    Everyone back to work now.

     

    p.s. that forecast probably applies to any seasonal winter forecast around here, but NINA's all the time

    That's where analog years can come in handy imo.  Forecasting the exact timing of blocking to develop is nearly impossible, but analogs can give hints at whether we should anticipate blocking to develop in the longer range.


  5. 27 minutes ago, Bob Chill said:

    I'm not really that big on analogs anymore to be honest. I think enso climo in general will tell us most of what we need to know. As we move forward in time, analogs from the 50s-70s become less useful because average heights have trended higher around the entire planet during the last 30 years. Because of this, even the same general height patterns in the 50s-70s are less likely to produce the same results if they happen today. Not implying that the same pattern will be wildly different wx wise or anything. Just that the climate isn't static and we have gone through some fairly rapid changes around the globe the last 30 years compared to the last hundred years before that. This is probably more apparent in the SE and MA and not as much the further you go north. "Slightly warmer versions" of identical patterns can substantially affect what is most important to us....snowfall. The SE probably agrees with my thoughts as well. 

    Another thing that makes analogs tricky is the short window. We spend a lot of time discussing and analyzing a short 12-14 week window. Analogs are good for generalizations but chaos and timing differences embedded in similar patterns often don't produce similar results. For example, if 2 winters have the same general pattern progressions but the timing is different by as little as 2-3 weeks, it can make a big difference. So much so that even if the patterns evolved in similar fashions, the personality (or memory) of the 2 winters could be very different. In our area a cold and wet last 2 weeks of Nov is usually very different than cold and wet first 2 weeks of Dec. Same thing happens at the end of met winter as we move through the end of Feb into early March. 

    Most seasonal forecasts use probabilistic forecasting for a good reason. Now that enso has come into focus and long range models actually have decent skill, it's kinda easy to make a general probabilistic outlook right now. Chances of below normal snowfall is higher than above normal. Temps are probably equal chances with hedge towards above normal. Of all the factors (temps, snow, precip) I think precip has the highest chance at being below normal compared to the other factors.  I probably won't change my mind on this until if/when something makes me do it in Dec. 

     

    It doesn't mean those of us who want to use analogs shouldn't. :snowman:


  6. 5 hours ago, showmethesnow said:

    He actually used 2 variables, -Enso and a -PDO which are the major drivers in regards to the Pacific. Though I would like to see the values with these 2 narrowed somewhat they should still give us a fairly good read on what the state of the Pacific will be irregardless of the other indices. So I am not really sure having such a large set with open ended values on some of the indices that affect our neck of the woods matters that much when looking upstream. Now downstream of the Pacific is another story. Without narrowing the goal posts on NAO/AO we are pretty much flying blind and anything being spit out by the composite for the eastern half of the US is probably useless. Now maybe the QBO will play a role in everything but I am not going to even pretend I know anything about it so I left it out of the discussion.

    So in other words. Everything is pointing to a hostile Pacific and we need to pray for blocking to have any hope of overcoming it.

    I completely agree.  Good analyses there!

    • Like 1

  7. 1 minute ago, Bob Chill said:

    There is some merit to the premise honestly. Just like the active Atlantic tropical season. That WDI was basically off the charts. Things have a way of evening out. Sometimes in historic ways (like the temporary end of CA's drought). Embedded in the chaos of weather is order and predictability over longer timescales. 

    :thumbsup: