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John1122

January 2019 Medium/Long Range Pattern Discussion

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The FV3 is still in build a glacier mode from the Plateau and westward.  Air behind the front is much colder on it vs the other models. Lots of freezing rain/sleet/snow for especially for Middle and Western areas.

A lot of this is freezing rain/sleet. Pivotal has much better snow maps for this model but they come in much slower.

Also, the FV3 skips a ton of frames later in the run but it looks like interesting weather may be happening for us during the missing frames.

fv3p_mslp_pcpn_frzn_eus_18.png

fv3p_mslp_pcpn_frzn_eus_19.png

fv3p_asnow_eus_22.png

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Pivotal maps for the midweek system on the FV3. Devastating ice followed by some nice snows. Also some sleet in here somewhere. The freezing rain map shows some of the ice in the central valley of east Tennessee along the edges of the Plateau in Roane/Anderson/Union County. Those areas are in the .5-.75 ice range there. This is the most extreme model of the bunch but it's been very good with surface features in the 5 day range. We will see how close it is here. 

 

zr_acc.us_ov.png

snku_acc.us_ov.png

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John's thoughts pretty much sum it up for me too.  Didn't really expect any model to hold onto the utterly extreme solution multiple runs. Though.....it seems like each of the models are throwing something similar to those 12-18z runs yesterday once out of every 3 or 4 runs lately. 

I feel like I have to balance out my excitement from yesterday's arctic apotheosis with some reality:

Still a lot of uncertainty (some better some worse) where the mid week system tracks as John said, and here's a visualization of that:

giphy.gif

Some of y'all may know what this is, but if not, these are isobars surrounding lows, projected by the 50 EPS members, for the midweek system. So this is how the 50 different setups look, all at once. Different colors denote different strengths of the low each member is showing.

Below is what more agreement  looks like. This is this weekend's system:

giphy.gif 

 

 

 

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Just a couple of quick AM notes:

Next week:  I think it is after next weekend that TRI/E TN folks will have their chances.  While I definitely think suppression is going to be an issue, I think the pattern remains active.  One trend I have noticed is for northern stream systems to tap the GOM as they slide by.  I would be very surprised if we have a dry pattern at any point this winter.  If you remember WxBell's snow forecast for winter, E TN was the center of a large area of AN snow departures w the entire forum area being snow.  I think that was made with the idea that the cold would settle into the Ohio River Valley w storms rotating under it w split flow and from northern stream systems.  We may actually see snow from systems in both streams.  While we often see dry patterns develop with eastern troughs, there have been some occasions where precip does not exit the pattern.  I think suppression(just a hunch) in the future will likely mean that the snow axis that has run from Kansas to the MA and NE will likely sag over the forum area and maybe the northern areas of the Gulf states.  

LR:  I know most of the discussion has been oriented to the short range.  However, I was not a fan of the 500 pattern evolution on all major ensembles(0z EPS, 6z GEFS, 0z EPS) once we enter February(days 10-15).  Now, this could easily be models trying to break down blocking too quickly over NA.  The trend I am noticing is for heights to drop over the NW and then hook into BN heights over the eastern Pac.  That pops a weak ridge over TX or the east.  IMHO, that is a scenario that could pull the trough West.  Another option is that this is how how the nationwide trough on the Weeklies develop.  Just a heads-up that things looks somewhat squirrelly at that range, and is not totally unexpected given how models have tried to break down blocking too quickly in the past.    Interestingly the surface pattern and 500 pattern on the EPS are out of sync late in its run.  The cold is in the East but the 500 pattern implies it might shift to the nation's mid-section.  

That is about it...posting just once or twice a day right now until things get active.  GBO.

Edit:  One final note, the 30 day SOI is now negative though the daily has been positive for the past three days(looks like it is coming back down).  It is interesting that the eastern trough is about to makes its presence known within just a few days of that 30 day index going negative.

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53 minutes ago, John1122 said:

Pivotal maps for the midweek system on the FV3. Devastating ice followed by some nice snows. Also some sleet in here somewhere. The freezing rain map shows some of the ice in the central valley of east Tennessee along the edges of the Plateau in Roane/Anderson/Union County. Those areas are in the .5-.75 ice range there. This is the most extreme model of the bunch but it's been very good with surface features in the 5 day range. We will see how close it is here. 

 

zr_acc.us_ov.png

snku_acc.us_ov.png

Yea, I am pretty close to that area north Nashville that is depicted nearing an inch of freezing rain, not good, not good at all. 

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Just tagging on to my last post...the Weeklies from Thursday have nearly an identical progression at 500.  The trough backs into the NW on its d17(now day 15), and then eventually discharges after a couple of days into the SE as blocking at higher latitudes does its job.  While the look on ensembles is mildly concerning, the Weeklies have the same look and remain very cold for the aforementioned entire run.  They ram the trough right back into the east.  I had not noticed this before, because I had simply looked at the weekly averages.  The daily means have that look/progression.  It would also explain why the 500 and surface patterns look different.  It may be that the surface pattern changes very little.

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Actually now that you mention it Carvers, wish I had been paying more attention to the EPS. I saw that the GEFS had shifted, but thought, 'blahhh, it's just the GEFS'. I just saw it while cruising another board, so didn't think much of it. But yeah, EPS is changing things up in the long range. 

For those without access here it is:

giphy.gif 

I wonder if some of the ensemble members are amping the MJO convection in the Maritime continent and leading to a reinforced/ extended Pac jet and those ensemble members are balancing out the ones that maintain the the blockier pattern up top. Looking at the RMM plots (presumably showing how the models see the convection developing through time) most of the ensembles go through the "bad" phases, some higher and some lower, so you end up with something like what you see on the 0z EPS. It would make sense that if that were the case, it would be reflected at the end of its run, since it takes a week? (not sure) for that whatever the convection does over the E Pac to percolate downstream to us. I had read that the tropical atmosphere was less conducive for amped convection after the SSW, and for sure, even at it's worst projection on the EPS or GEFS RMM plots it doesn't get to where it was last month, but you have to think any convection there at even a modest amplitude might have some effect.  Good news is no coronal holes predicted by NCHailstorm and even the most amped of the ensembles scoot it through to the COD by the end of the month. 

Now what the RMM plots show and actual outcome may be two entirely different things. I know there has been talk about it being muted and maybe it will be as it develops in real time the actual atmosphere, but that doesn't mean the models will necessarily see it that way. 

Maybe another way to look at it is the filtered plot:

filterMJO_vp_Phase.png

Definitely looks like a better progression when some of the noise (at least I think that's how this one works) is filtered out

You'd also have to think if we do get even a milder version of the TPV drop into the Ohio Valley/ Midwest some runs  of the models are spitting out an extreme event like that would have a "snapback" or pendulum swing effect as things eventually balance out. 

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4 minutes ago, Holston_River_Rambler said:

Actually now that you mention it Carvers, wish I had been paying more attention to the EPS. I saw that the GEFS had shifted, but thought, 'blahhh, it's just the GEFS'. I just saw it while cruising another board, so didn't think much of it. But yeah, EPS is changing things up in the long range. 

For those without access here it is:

giphy.gif 

I wonder if some of the ensemble members are amping the MJO convection in the Maritime continent and leading to a reinforced/ extended Pac jet and those ensemble members are balancing out the ones that maintain the the blockier pattern up top. Looking at the RMM plots (presumably showing how the models see the convection developing through time) most of the ensembles go through the "bad" phases, some higher and some lower, so you end up with something like what you see on the 0z EPS. It would make sense that if that were the case, it would be reflected at the end of its run, since it takes a week? (not sure) for that whatever the convection does over the E Pac to percolate downstream to us. I had read that the tropical atmosphere was less conducive for amped convection after the SSW, and for sure, even at it's worst projection on the EPS or GEFS RMM plots it doesn't get to where it was last month, but you have to think any convection there at even a modest amplitude might have some effect.  Good news is no coronal holes predicted by NCHailstorm and even the most amped of the ensembles scoot it through to the COD by the end of the month. 

Now what the RMM plots show and actual outcome may be two entirely different things. I know there has been talk about it being muted and maybe it will be as it develops in real time the actual atmosphere, but that doesn't mean the models will necessarily see it that way. 

Maybe another way to look at it is the filtered plot:

filterMJO_vp_Phase.png

Definitely looks like a better progression when some of the noise (at least I think that's how this one works) is filtered out

You'd also have to think if we do get even a milder version of the TPV drop into the Ohio Valley/ Midwest some runs  of the models are spitting out an extreme event like that would have a "snapback" or pendulum swing effect as things eventually balance out. 

Do you have access to the daily means on the Euro Weeklies?  Days 17-25 would be a great GIF of how it "thinks" things play out.  I added one more post which explains the progression.  It might be a 72-96 hour trough in the NW at 500.  The EPS surface is still cold in the East, even at d15.  The trough at 500 comes back into the East.  The 0z EPS and TR's Weeklies look almost identical with that progression.  Monster trough in the East follows.  

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50 minutes ago, Holston_River_Rambler said:

Actually now that you mention it Carvers, wish I had been paying more attention to the EPS. I saw that the GEFS had shifted, but thought, 'blahhh, it's just the GEFS'. I just saw it while cruising another board, so didn't think much of it. But yeah, EPS is changing things up in the long range. 

For those without access here it is:

giphy.gif 

I wonder if some of the ensemble members are amping the MJO convection in the Maritime continent and leading to a reinforced/ extended Pac jet and those ensemble members are balancing out the ones that maintain the the blockier pattern up top. Looking at the RMM plots (presumably showing how the models see the convection developing through time) most of the ensembles go through the "bad" phases, some higher and some lower, so you end up with something like what you see on the 0z EPS. It would make sense that if that were the case, it would be reflected at the end of its run, since it takes a week? (not sure) for that whatever the convection does over the E Pac to percolate downstream to us. I had read that the tropical atmosphere was less conducive for amped convection after the SSW, and for sure, even at it's worst projection on the EPS or GEFS RMM plots it doesn't get to where it was last month, but you have to think any convection there at even a modest amplitude might have some effect.  Good news is no coronal holes predicted by NCHailstorm and even the most amped of the ensembles scoot it through to the COD by the end of the month. 

Now what the RMM plots show and actual outcome may be two entirely different things. I know there has been talk about it being muted and maybe it will be as it develops in real time the actual atmosphere, but that doesn't mean the models will necessarily see it that way. 

Maybe another way to look at it is the filtered plot:

filterMJO_vp_Phase.png

Definitely looks like a better progression when some of the noise (at least I think that's how this one works) is filtered out

You'd also have to think if we do get even a milder version of the TPV drop into the Ohio Valley/ Midwest some runs  of the models are spitting out an extreme event like that would have a "snapback" or pendulum swing effect as things eventually balance out. 

  Much cleaner look to that MJO depiction, I like it.  If you don’t mind me asking, where do you find that map at?

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21 minutes ago, AMZ8990 said:

If you don’t mind me asking, where do you find that map at?

http://mikeventrice.weebly.com/mjo.html

He has a variety of approaches to plotting the MJO, plus a link to the CPC's page that has all major global models' depictions as well. 

Sometimes I think the RMM/ Wheeler plots (what you usually see when you see people posting MJO plots) are really only useful after the fact, that is to say they do a good job of showing you how things stand and how you got there, but not always where things are going. All convection pulses, waxes, and wanes. We've all experienced summer T-storms and know this. I think his different plots try to filter out some of this waxing and waning, but could be misinterpreting. As I understand it, again, could be wrong, the MJO as it is plotted on the RMM plots is not necessary a discrete wave that moves around the tropics (I think it can be that way when it is very strong), but more a measurement of convection in the tropics at any given time. 

I put this on a post a while back and will throw it out here again at the risk of too much Masiello:

 My interpretation of what he is saying:

Long story short, MJO is going back to the bad phases, but it will be different this time because of the background state. If you read through the whole series of messages, he seems rather optimistic to me about the whole progression.  

 

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1 minute ago, Holston_River_Rambler said:

6z Euro:

giphy.gif

It this point though, I'd say just watch radar trends, since these comma head/ TROWAL type features are notoriously hard to pin down, even last minute. 

Goodness gracious, that would be a big time surprise if that happens for me.  I’d gladly take 3 inches of surprise snow!!!  Thanks for sharing Holston.

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14 minutes ago, Will (little rock) said:

Past this storm, looking waaaaaay out to next weekend, there seems to be some similarities with a system between the FV3, GFS, and CMC. Still far out but still worth watching

There is definitely a strong signal for next weekend on several of the models.  Hopefully that trend continues over the next few days.

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5 hours ago, Holston_River_Rambler said:

I think this is it:

giphy.gif 

And that would make sense. You get one more Pac jet extension and then things settle out. 

My mistake.  I was in a hurry and didn't pay attention to the toggle.  It was the control that showed the almost exact progression.  BTW, the 12z EPS looks better at that time frame...12z GEFS doubled down.

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Yeah the 12z shows a similar progression. Ridge over AK goes way up, lower heights attempt to tuck underneath, then the ridging in the southwest starts to sort of pivot from Baja and move into what will hopefully be a PNA-ish position down the road, as the lower heights of the Pac coast start to slip north and west  You can even see this starting (if you squint and imagine a bit, lol) at the very end of the 12z EPS:

giphy.gif 

It's so subtle to my eye that I may just looking through rose colored glasses.

I really think (hope) the EPS is just seeing what it thinks is a temporary jet extension from the Pac convection it expects to fire up.

giphy.gif 

The jet could also be smoothing over a spread though at that range. 

What I'm about to post may not make a lot of sense, but I'm going to give it a stab. One thing I noticed about the weeklies, the last time I got the hindcast series and could make a gif to watch the progression, was that the 500mb anomalies seemed to do progress differently at different latitudes. Highest latitude anomalies seemed to progress counter clockwise to lock in, while the 500mb anomalies at the mid latitudes seems to progress clockwise through the run to get where they ended up. I'm going to go back through the thread and see if I can find the gif I'm talking about. 

Here it is:

giphy.gif 

Looking back at that maybe my clockwise/ counterclockwise bit wasn't the best explanation, but you can definitely see on weeks 4 - 5 on there how the end of the EPS could turn into more of a PNA with time 

 

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Backside snow holding together for our friends in left Tennessee


.
I was just about to post the same. Still seeing returns as far south and west as Little Rock.Screenshot_20190119-172728_Weather.jpeg

Sent from my SM-G965U using Tapatalk

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5 hours ago, HSVWx said:

Ahhh, I understand. Thanks. I sure would like to see Huntsville's number down the road

No problem posting your area,i'll include you next time

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For a great example of interesting 500 patterns and a surface pattern that does not correspond...take a look at the 500 pattern late on the GEFS and then we look at temp anomalies. 

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2 minutes ago, Carvers Gap said:

For a great example of interesting 500 patterns and a surface pattern that does not correspond...take a look at the 500 pattern late on the GEFS and then we look at temp anomalies. 

Dont take this the wrong way, but what does that mean? What happened to the really cold air we were seeing modeled yesterday. 

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