December Med/Long Range Disco

[nj2va]

Wes, today's 12z d15 gefs and euro ens are very similar. Euro has the trough axis further east than the gefs but basically the same. Encouraging to see both globals looking that similar so far out in time.

-ao starting to show up as well but not strong signal.

 

Bob, WRT to the bolded statement, I was looking at the GEFS 500mb anomalies map, and I was thinking the same regarding the AO but I wasn't sure if I was reading it correctly.  Looking at the map below, specifically discussing the AO, we would want the positive anomalies to be stronger, more consolidated, and centered over the pole/northern Greenland?  Definitely a much better look though than what we are currently seeing.

[Bob Chill]

Nj2va, numerically that would be a -ao. Not below 1sd I don't think. From a height pattern perspective it's ok but not particularly close to what we really like to see. A nice step in the right direction and hopefully part of the process that fills the area with more consolidated higher height anoms.

[Bob Chill]

Since we are in a crappy snow pattern but still keeps trying to make things interesting anyway...it's probably worth keeping a casual eye on the d9-12 period. Op's and ensembles are pretty close in depicting a sw tracking through the sw but not gaining latitude. Some closed low solutions as well.

Obviously a low prob event but there seems to be good support considering the lead.

[poolz1]

I will gladly accept 1-2" of cold rain this week as long as the 18z gfs ens verify.  Pre xmas looks festive...

[AlaskaETC]

I like this analog from Andrew's Weather Center blog...

 

https://www.facebook.com/TheWeatherCentre/photos/a.197474410300620.47774.172642852783776/791116657603056/?type=1&theater

[Bob Chill]

Wes' next article should be a good one. 

 

 

 

[AlaskaETC]

Wes' next article should be a good one. 

 

 

 

gefs.JPG

 

That looks tasty...

[WxUSAF]

Wes' next article should be a good one. 

 

 

 

gefs.JPG

That deserves a

 

+PNA/-EPO/-AO/-NAO  let's do it

[Bob Chill]

That looks tasty...

 

This plot answers how fast the AN temps in Canada can reverse. If the pattern verifies then there will be plenty of cold air to tap. Not arctic hound stuff but we don't need that at all. 

 

[Bob Chill]

That deserves a

 

+PNA/-EPO/-AO/-NAO  let's do it

 

How about the sag in the heights down by baja? You forgot to add active STJ and split flow to your list. LOL

[WxUSAF]

How about the sag in the heights down by baja? You forgot to add active STJ and split flow to your list. LOL

For real, that's a really nice pattern.  Let's get it to Day 10.  I'm eager to see what the superensemble analogs would be for such a setup. 

 

As for your picture with the 2m temp anomalies:  I wouldn't put much stock in the actual numbers there, but I think the trend is valid.  With the 500mb depiction in the model, Canada will be recharged with some cold air and we'll have some chilly days, but nothing record breaking as you mentioned.  Certainly the pattern would suggest snow chances. 

[Bob Chill]

For real, that's a really nice pattern. Let's get it to Day 10. I'm eager to see what the superensemble analogs would be for such a setup.

As for your picture with the 2m temp anomalies: I wouldn't put much stock in the actual numbers there, but I think the trend is valid. With the 500mb depiction in the model, Canada will be recharged with some cold air and we'll have some chilly days, but nothing record breaking as you mentioned. Certainly the pattern would suggest snow chances.

Agree on 2m temps. Very broad brushed once you get beyond d7. But the turnaround in Canada to bn is really quick. Just making the point that once you shut off the pac flood things can turn quick.Normal temps in central Canada are plenty cold for our source. If h5 verifies there will be plenty of cold pooling there and down through the lakes.

[mitchnick]

How about the sag in the heights down by baja? You forgot to add active STJ and split flow to your list. LOL

some high octane juice to the W/SW of California that can only be helping

[AlaskaETC]

How about the sag in the heights down by baja? You forgot to add active STJ and split flow to your list. LOL

 Triple phaser or bust.

[usedtobe]

For real, that's a really nice pattern.  Let's get it to Day 10.  I'm eager to see what the superensemble analogs would be for such a setup. 

 

As for your picture with the 2m temp anomalies:  I wouldn't put much stock in the actual numbers there, but I think the trend is valid.  With the 500mb depiction in the model, Canada will be recharged with some cold air and we'll have some chilly days, but nothing record breaking as you mentioned.  Certainly the pattern would suggest snow chances. 

It would suggest snow chances,  It's the 1st pattern where I'd put the chances higher than normal if I see it on at 11-15 day forecast when doing and outlook. 

[CAPE]

Since we are in a crappy snow pattern but still keeps trying to make things interesting anyway...it's probably worth keeping a casual eye on the d9-12 period. Op's and ensembles are pretty close in depicting a sw tracking through the sw but not gaining latitude. Some closed low solutions as well.

Obviously a low prob event but there seems to be good support considering the lead.

0z Euro EPS looks a tad interesting @240

 

[yoda]

Days 8-10 on tonights EURO seeing the h5 chart and the track of the low piqued my interest... until I checked the 850s

[NaoPos]

Days 8-10 on tonights EURO seeing the h5 chart and the track of the low piqued my interest... until I checked the 850s

Yea, it's just an ULL stuck under the ridging to the north. Nothing really special about it.

[CAPE]

Days 8-10 on tonights EURO seeing the h5 chart and the track of the low piqued my interest... until I checked the 850s

lol its 10 days out. And even so 850 mb temps arent bad on the ens mean, at least the map I saw. Its something to watch. Although in the evolution in of the pattern change(as it looks now), it could be a bit too soon for a legit snow threat.

[CAPE]

Yea, it's just an ULL stuck under the ridging to the north. Nothing really special about it.

Yup. Nothing to see here 

[H2O]

Encouraging signs, no doubt, but the proof is in the pudding.  These things need to happen and not just be model fantasy

[HM]

With the arrival of the insane Pacific Jet this week, it will kick off a parade of southern stream lows--one after another. Models, especially ensemble means, will average this out in the day 10-15 period and make it look like some "3-wave configuration" etc. But in reality, a classic PNA, split flow will develop and models will screw-up this separation (especially the GFS). So, expect continued correcting from a smoother, longer wavelength to a shorter wavelength/split stream from the day 10-15 means to day 6-10 means.

There is NO torch coming and eventually these monster southern lows will pay off...

[mitchnick]

With the arrival of the insane Pacific Jet this week, it will kick off a parade of southern stream lows--one after another. Models, especially ensemble means, will average this out in the day 10-15 period and make it look like some "3-wave configuration" etc. But in reality, a classic PNA, split flow will develop and models will screw-up this separation (especially the GFS). So, expect continued correcting from a smoother, longer wavelength to a shorter wavelength/split stream from the day 10-15 means to day 6-10 means.

There is NO torch coming and eventually these monster southern lows will pay off...

[HM]

So when you're on social media and you read from certain outfits who say things like, "this stratospheric warming appears to have originated from the troposphere," that is a dead give-away that they don't understand anything about the stratosphere. If you read things like, "the warm anomaly in the stratosphere has moved to North America and this will change the pattern," you can go ahead and assume they are clueless. In fact, calling any warming a SSW is a dead give-away they know nothing.

[mappy]

With the arrival of the insane Pacific Jet this week, it will kick off a parade of southern stream lows--one after another. Models, especially ensemble means, will average this out in the day 10-15 period and make it look like some "3-wave configuration" etc. But in reality, a classic PNA, split flow will develop and models will screw-up this separation (especially the GFS). So, expect continued correcting from a smoother, longer wavelength to a shorter wavelength/split stream from the day 10-15 means to day 6-10 means.

There is NO torch coming and eventually these monster southern lows will pay off...

 

reading between the lines, i think you are suggesting a 12/19 repeat

[Bob Chill]

So when you're on social media and you read from certain outfits who say things like, "this stratospheric warming appears to have originated from the troposphere," that is a dead give-away that they don't understand anything about the stratosphere. If you read things like, "the warm anomaly in the stratosphere has moved to North America and this will change the pattern," you can go ahead and assume they are clueless. In fact, calling any warming a SSW is a dead give-away they know nothing.

It's always a buzzword when things aren't quite right. Always feels like people are reaching for the piece of the puzzle to tip things. The hype seems to lead casual readers to believe that a SSW is a necessary or required component for blocking to set up. And it's a shame because it's not required if pattern sets up right. I only listen to a couple folks for SSW events with you being the main one.

I also agree about the possibility of having one of the southern lows producing this month. We're still in tough climo here so hopefully there's a cold air source signal at medium leads if/when one approaches that looks half decent. The shorter wavelengths could help by having one that doesn't work prime the atmosphere for one on the heels.

[WinterWxLuvr]

reading between the lines, i think you are suggesting a 12/19 repeat

That's how I read it too.

[HM]

reading between the lines, i think you are suggesting a 12/19 repeat

haha...you know me, any chance I get I hype up a good blizzard for DC. I like the idea of a 1986-87 pay-off where a classic Nino southern stream runs into a mid-winter air mass. The NAO will start to come around, finally, next month. And as many other folks have indicated, that's obviously when things get interesting. But what's the use of me saying that when you are talking about January-February! lol There's just something funny about predicting snow these two months!

[HM]

It's always a buzzword when things aren't quite right. Always feels like people are reaching for the piece of the puzzle to tip things. The hype seems to lead casual readers to believe that a SSW is a necessary or required component for blocking to set up. And it's a shame because it's not required if pattern sets up right. I only listen to a couple folks for SSW events with you being the main one.

I also agree about the possibility of having one of the southern lows producing this month. We're still in tough climo here so hopefully there's a cold air source signal at medium leads if/when one approaches that looks half decent. The shorter wavelengths could help by having one that doesn't work prime the atmosphere for one on the heels.

Well said Bob, well said! The ozone layer, i.e. a warming agent of the stratosphere, will occasionally cause anomalous warmth should planetary waves break and slow down the jet up there. Not all of these disturbances produce a SSW and not all SSW are the same/important. But every year, we go through the same crap from the same people who never bother to pick up a paper or two. Oh and by the way, this subject has been studied since the 1950s....this isn't some new thing.

[HM]

That's how I read it too.

Let's think about this logically. Think about how close a few of these storms have been to being decent events. The background state from the Pacific will not change so we shouldn't expect a big SE ridge pattern in the long-term means any time soon. Therefore, each week, it can only grow colder as we had towards climatological minimum. Eventually, these lows will become legitimate snow threats...and that's just with the current pattern and background state. I didn't even touch the potential for a significant AO/NAO decrease mid-winter.