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December Med/Long Range Discussion Part 2


WinterWxLuvr

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Hi guys. SE Forum guy here. I occasionally lurk over here and read, but not post. I seem to be caught in the in-between area which lies not quite SE Forum and not quite MA Forum (Northeast NC, an hour south of Virginia Beach). That being said, I read Isotherm's post. I'm an educated man and and still learning about weather and all that encompasses it, but his post (which could easily qualify as a doctoral disseratation, LOL) absolutely mesmerized me. I don't know a thing about the MJO (still learning) except that 7,8, and 1 are better for the East Coast, but he lost me on Rossby Waves. Now I have to go do research since I'm an analytical person and don't like reading something without understanding it.

 

Mods: If this belongs in banter, I profusely apologize.

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22 minutes ago, tramadoc said:

Hi guys. SE Forum guy here. I occasionally lurk over here and read, but not post. I seem to be caught in the in-between area which lies not quite SE Forum and not quite MA Forum (Northeast NC, an hour south of Virginia Beach). That being said, I read Isotherm's post. I'm an educated man and and still learning about weather and all that encompasses it, but his post (which could easily qualify as a doctoral disseratation, LOL) absolutely mesmerized me. I don't know a thing about the MJO (still learning) except that 7,8, and 1 are better for the East Coast, but he lost me on Rossby Waves. Now I have to go do research since I'm an analytical person and don't like reading something without understanding it.

 

Mods: If this belongs in banter, I profusely apologize.

Knock yourself out!  The MJO phases also depend on the time of year. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/

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30 minutes ago, tramadoc said:

Hi guys. SE Forum guy here. I occasionally lurk over here and read, but not post. I seem to be caught in the in-between area which lies not quite SE Forum and not quite MA Forum (Northeast NC, an hour south of Virginia Beach). That being said, I read Isotherm's post. I'm an educated man and and still learning about weather and all that encompasses it, but his post (which could easily qualify as a doctoral disseratation, LOL) absolutely mesmerized me. I don't know a thing about the MJO (still learning) except that 7,8, and 1 are better for the East Coast, but he lost me on Rossby Waves. Now I have to go do research since I'm an analytical person and don't like reading something without understanding it.

 

Mods: If this belongs in banter, I profusely apologize.

Here's a good, high-level primer on the MJO.

https://www.climate.gov/news-features/blogs/enso/what-mjo-and-why-do-we-care

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10 hours ago, Bob Chill said:

For those of you including me that doesn't fully grasp what Isotherm just said I'll make it much easier. He said we're totally fooked for a while and one of the few things that might break things in our favor is the fabled attack on the stratosphere that may or may not happen and even if it does it might not do anything or if successful it might be too late to save our region. 

Isotherm's winter outlook is looking spot on so far. The strat rules the SAI. 

I believe from a non-science perspective with a historical view, there have been many times where weeks and weeks of warm temps have reversed in late Jan and in mid Feb leading to some rather memorable snowstorms.  Sure for this to happen it would have to occur in the present backdrop of the AO which  is is averaged positive, but do I like Isotherm's analysis, and not just because it offers some glimmers of hope in Feb .

All hope might not be lost. 

  

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14 minutes ago, showmethesnow said:

They do have this, a weather classroom. Or are you talking something a little different?

https://www.americanwx.com/bb/forum/30-meteorology-101/

Not even close. I said it would be nice to have archived links. We use them so often that I'd like to see them organized similarly to what I did with my ancient website. (No self-promotion here) https://sites.google.com/site/btrweather/home/Recommended-Weather-Websites

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11 hours ago, Bob Chill said:

For those of you including me that doesn't fully grasp what Isotherm just said I'll make it much easier. He said we're totally fooked for a while and one of the few things that might break things in our favor is the fabled attack on the stratosphere that may or may not happen and even if it does it might not do anything or if successful it might be too late to save our region. 

Thanks Bob. It is unfortunate to see the first half of winter largely flushed down the drain again, but until we have a regime shift, it's difficult to achieve a cold early winter without Arc / Atl help.

To address a couple comments I read regarding rossby waves and the stratosphere -- downward propagation of geopotential height anomalies is rather individualistic in that the haste with which it occurs is contingent upon other variables. One can have a tropospheric and stratospheric regime which is already conducive for rapid unification of either strong or weak vortex conditions. Sometimes SSW events will take the typical circa 2 weeks for propagation, sometimes it will be seemingly instantaneous  (days), and still other times, a SSW event may not effectively reach the troposphere at all, or potentially even induce a more positive NAM in the worst case. This is why, as someone noted earlier, banking on a SSW to alter a poor winter background regime is certainly a risky proposition. The exogenous forcing of westerly shear stress via the QBO is one example of a factor that can destructively interfere with effective downward propagation. Right now, the tropospheric factors are already supportive of a stronger trop vortex, so the consolidation of the strat vortex, coupled with other signals such as the QBO, can lead to a rapid alignment of the vortex vertically. 

In order to reverse this situation, I think we need help from the Pacific via an improved tropical forcing pattern and this convection can generate rossby waves which influence the extratropical circulation and also strat perturbation. We need additional significant pressure on the vortex. Even if we don't  force a SSW, another more realistic possibility might be to sufficiently attack the vortex to induce elongation, like we saw in prior recent winters. The aleutian stratospheric high has been absent and that would reshuffle the situation via applying pressure. 

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1 minute ago, Isotherm said:

Thanks Bob. It is unfortunate to see the first half of winter largely flushed down the drain again, but until we have a regime shift, it's difficult to achieve a cold early winter without Arc / Atl help.

To address a couple comments I read regarding rossby waves and the stratosphere -- downward propagation of geopotential height anomalies is rather individualistic in that the haste with which it occurs is contingent upon other variables. One can have a tropospheric and stratospheric regime which is already conducive for rapid unification of either strong or weak vortex conditions. Sometimes SSW events will take the typical circa 2 weeks for propagation, sometimes it will be seemingly instantaneous  (days), and still other times, a SSW event may not effectively reach the troposphere at all, or potentially even induce a more positive NAM in the worst case. This is why, as someone noted earlier, banking on a SSW to alter a poor winter background regime is certainly a risky proposition. The exogenous forcing of westerly shear stress via the QBO is one example of a factor that can destructively interfere with effective downward propagation. Right now, the tropospheric factors are already supportive of a stronger trop vortex, so the consolidation of the strat vortex, coupled with other signals such as the QBO, can lead to a rapid alignment of the vortex vertically. 

In order to reverse this situation, I think we need help from the Pacific via an improved tropical forcing pattern and this convection can generate rossby waves which influence the extratropical circulation and also strat perturbation. We need additional significant pressure on the vortex. Even if we don't  force a SSW, another more realistic possibility might be to sufficiently attack the vortex to induce elongation, like we saw in prior recent winters. The aleutian stratospheric high has been absent and that would reshuffle the situation via applying pressure. 

my question is how does the artic cyclone get so strong that it becomes so over whelming?? is this due to MJO, or other main driving factor??

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16 minutes ago, mdsnowlover said:

my question is how does the artic cyclone get so strong that it becomes so over whelming?? is this due to MJO, or other main driving factor??

Thats the same question I have for ISO.  Is the MJO the biggest player in causing any perturbing of the PV?  It would make sense as physics would imply the need of an equal or greater force to have any noteable affect.  In my efforts to continue to undertstand the hierachy of global forcing mechanisms, one would think that NAO/AO/PNA etc. are largely driven by source regions w/ the most energy available.

Nut

 

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3 minutes ago, pasnownut said:

Thats the same question I have for ISO.  Is the MJO the biggest player in causing any perturbing of the PV?  It would make sense as physics would imply the need of an equal or greater force to have any noteable affect.  In my efforts to continue to undertstand the hierachy of global forcing mechanisms, one would think that NAO/AO/PNA etc. are largely driven by source regions w/ the most energy available.

Nut

 

another question, how does a stratawarming event get started?? what control this feature??

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35 minutes ago, Isotherm said:

Thanks Bob. It is unfortunate to see the first half of winter largely flushed down the drain again, but until we have a regime shift, it's difficult to achieve a cold early winter without Arc / Atl help.

 

I totally understand Iso. I've been at this long enough to know when there's trouble in the kitchen. I also understand that the strat-trop relationship is far from 1:1. Blocking in the trop comes in many forms too. 13-14/14-15 look pretty tame on the means irt the AO/NAO but the h5 plots show a different story when things were going well. The -epo/scand ridge connection is a form of blocking that can be very favorable for the east when it has enough oomph to suppress the trop PV to HB or even further south. The mid latitude response is very conducive for cold outbreaks in the east. Storm track hinges on the ever moving baroclinic zone though. Landing on the right side (or better known as the left side..lol)  this far south requires a great deal of good fortune. It's not like that type of long wave pattern is always friendly. In fact, I would say it is hostile for snow in our region (ala 93/94) but with enough amplification we can end up on the right side of things from time to time. 

The current state and forecast of the AO is pretty troubling going off of past history. The cases of a Dec AO @ +1.5 or more shows the resilience of the pattern in stark fashion. The cases do show that high latitude blocking can develop but it is rarely long lived and the good periods are buried underneath a hostile monthly mean. The base state (when anomalous) in December is probably one of the more reliable forecasting tools as far as I can tell. Regardless of the behavior of the strat or any other pattern driver like the MJO/enso/whatever, when December has an anomalous baseline state of the AO you can pretty much forecast that state to continue well into Jan and to a lesser extent Feb and have a very high forecast success rate. 

As we both know, whenever the strat and mjo become talking points in the winter during a crap period it means that we are in deep doo doo for a while and the way out is not easy nor is it likely. lol

 

 

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8 hours ago, mdsnowlover said:

from anthony maiesllo met  (How the hell do you move,dislodge a feature of this massive size??) this was supposed to be a video!!

This is like the biggest +NAO I've ever seen (not objective d

 

 

1993-94 winter had a +NAO also and look how this turned out!

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3 hours ago, pasnownut said:

yes, you are correct SSW events typically have a +/- 30-45 day lag from occurrence to downwelling and being seen in our sensible weather.  IT surely makes one wonder how the we seem to "snap back" to warmer so easily.  Something to think about.

Nut

 

Either the models are wrong or we are in a much warmer climate from now on, we shall see.

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Just now, Bob Chill said:

93-94 sucked here but I'm sure the INTERIOR loved it. 

It was icy for you guys, but NYC north did well. HM who I have been following lately as said it is more of an interior winter. I do think you will end up near average in snowfall, but temps may end up a little above average.

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1 minute ago, mdsnowlover said:

93-94 was solid ice and siberian air masses, the 2nd most miserable winter in my 68 years,you had to live in frostberg to get snow

I know even Philly did not do too well,except for ice. North and west did alot better as far as snowfall is concerned and I believe Allentown had nearly 3 times as much snowfall as philly did.

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1 minute ago, WEATHERBUFF said:

I know even Philly did not do too well,except for ice. North and west did alot better as far as snowfall is concerned and I believe Allentown had nearly 3 times as much snowfall as philly did.

the wash post had a write up on that winter and the reason for all the ice.According to NWS if the polar vortex near baffin bay, i believe in central canada, had been 20 miles farther east , we would have gotten snow. Its always something that isnt counted on.

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2 minutes ago, WEATHERBUFF said:

It was icy for you guys, but NYC north did well. HM who I have been following lately as said it is more of an interior winter. I do think you will end up near average in snowfall, but temps may end up a little above average.

 

Do you really think anyone here gives a rats ass about NYC, up north, INTERIOR, or carbondale? I mean seriously dude. Why are you even here? What value to you bring? Your posts are about as useful as getting lice in ball hair. 

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4 minutes ago, Bob Chill said:

 

Do you really think anyone here gives a rats ass about NYC, up north, INTERIOR, or carbondale? I mean seriously dude. Why are you even here? What value to you bring? Your posts are about as useful as getting lice in ball hair. 

Getting upset I see. Listen there are people in your area that live in the interior also. You mention HM but I guess you are not interested what he is saying.

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