December Med/Long Range Discussion Part 2

[showmethesnow]

The 00Z Euro op starts to set up a good look from day 7 onward with some nice blocking up top. It also pops a modest coastal around day 8 or so. But what I really like is the look at day 10. We have great blocking bridging from Alaska to Greenland with the day 8 coastal ready to move into the 50/50 spot. If this 240 hr were to verify I think there would be a bunch of happy campers in our region just a couple of days later. 

 

[Thanatos_I_Am]

The 00Z Euro op starts to set up a good look from day 7 onward with some nice blocking up top. It also pops a modest coastal around day 8 or so. But what I really like is the look at day 10. We have great blocking bridging from Alaska to Greenland with the day 8 coastal ready to move into the 50/50 spot. If this 240 hr were to verify I think there would be a bunch of happy campers in our region just a couple of days later. 

 

This may be a newbie question, but when I see 990> low in that spot I gotta think we are getting more than light snow showers. Why is that?

[winterymix]

27 minutes ago, Thanatos_I_Am said:

 

 

This may be a newbie question, but when I see 990> low in that spot I gotta think we are getting more than light snow showers. Why is that?

 

Too soon to know about surface details.  The encouragement arises from seeing the jet stream turn left across the baroclinic zone of the jet stream.

This looks like a nice pattern change coming as others have pointed out here.  It should be chilly at the surface with some blocking. 

[showmethesnow]

7 minutes ago, Thanatos_I_Am said:

 

This may be a newbie question, but when I see 990> low in that spot I gotta think we are getting more than light snow showers. Why is that?

 

 Normally the stronger the low the tighter the precip field on the left hand side will be. So as you see a low deepen you will also see the precip being pulled closer into the low. So in this case the combination of the low being a little to strong/to far east is putting our region just outside of the heavier bands. That being said, the Euro has a tendency to underplay precip intensity and expanse in the western sector of a low in the mid and long range so that possibility is also there.

[showmethesnow]

46 minutes ago, Thanatos_I_Am said:

 

This may be a newbie question, but when I see 990> low in that spot I gotta think we are getting more than light snow showers. Why is that?

 

 

9 minutes ago, showmethesnow said:

 Normally the stronger the low the tighter the precip field on the left hand side will be. So as you see a low deepen you will also see the precip being pulled closer into the low. So in this case the combination of the low being a little to strong/to far east is putting our region just outside of the heavier bands. That being said, the Euro has a tendency to underplay precip intensity and expanse in the western sector of a low in the mid and long range so that possibility is also there.

One of the exceptions to this general rule is when a strong low becomes closed/occluded. When this happens the precip can become quite expansive on the left hand side but will be lighter and more showery in nature.

[showmethesnow]

After watching the models slip somewhat the last couple of days it was nice to see the 00Z ensemble runs. There were some nice improvements on both the GEFS and the EPS.

[mdsnowlover]

1 hour ago, showmethesnow said:

After watching the models slip somewhat the last couple of days it was nice to see the 00Z ensemble runs. There were some nice improvements on both the GEFS and the EPS.

In regards to what specifically, cold, snow, blocking??

[frd]

1 hour ago, showmethesnow said:

After watching the models slip somewhat the last couple of days it was nice to see the 00Z ensemble runs. There were some nice improvements on both the GEFS and the EPS.

Yep, those were some major changes in the East for the better overnight  , both the GEFS and especially on the EPS .

 

 

 

[showmethesnow]

1 hour ago, mdsnowlover said:

In regards to what specifically, cold, snow, blocking??

Not going to break it down at this point but I am generally speaking on the overall pattern. Both models tweek different aspects of the major players (NAO, Alaskan ridge, SE ridge, trough placement , etc) that are driving the pattern. The look is more promising then what the models were trending towards the last day or two. Only one run so lets see if this continues on subsequent runs.

[psuhoffman]

4 hours ago, mdsnowlover said:

Doesn't 10 to15 days put  us  at beginning of phase 7 MJO, or about Jan 17th??? I wouldn't be a bit surprised if your correct in your assessments.Models should start showing snowy solution around the 10 day period. Just mho based on past experience.

It's dec 26. 10-15 days is Jan 5 -10.  Jan 17 is 22 days away. Way outside the range of anything were looking at. 

The good news is after Jan 3 or so the pattern is close enough that we could easily fall into a good look. Several runs hint at nao help. It's mostly transient but get a couple days with blocking and something could pop up. I'm not sold how good or how long the pattern lasts yet but there is reason for optimism we could get on the board during that period. 

[CAPE]

18 minutes ago, showmethesnow said:

Not going to break it down at this point but I am generally speaking on the overall pattern. Both models tweek different aspects of the major players (NAO, Alaskan ridge, SE ridge, trough placement , etc) that are driving the pattern. The look is more promising then what the models were trending towards the last day or two. Only one run so lets see if this continues on subsequent runs.

There are subtle improvements at h5 on the latest EPS, mostly the more eastward position of the AK ridge, but also the ridging near GL poking further west. The position of the AK ridge is key IMO. It has been too far west for much of this early winter. If we can get cooperation there, plus some modest help in the NAO region, we should have some opportunities to track in a week to 10 days.

[showmethesnow]

7 minutes ago, psuhoffman said:

It's dec 26. 10-15 days is Jan 5 -10.  Jan 17 is 22 days away. Way outside the range of anything were looking at. 

The good news is after Jan 3 or so the pattern is close enough that we could easily fall into a good look. Several runs hint at nao help. It's mostly transient but get a couple days with blocking and something could pop up. I'm not sold how good or how long the pattern lasts yet but there is reason for optimism we could get on the board during that period. 

I myself will be watching the runs with a little more interest the next couple days. After looking over the last few runs of both the op and ensembles I think the models may now possibly be keying on a prime threat window not just a favorable pattern. Roughly speaking day 9 through 14 and possibly even longer if the ESP is to be believed. But of course we are talking longer range with models that have not been exactly stellar in that range. So I guess we will see.

 

[showmethesnow]

39 minutes ago, C.A.P.E. said:

There are subtle improvements at h5 on the latest EPS, mostly the more eastward position of the AK ridge, but also the ridging near GL poking further west. The position of the AK ridge is key IMO. It has been too far west for much of this early winter. If we can get cooperation there, plus some modest help in the NAO region, we should have some opportunities to track in a week to 10 days.

To me the key is the NAO. Think we have some flex with the Alaskan ridge to make things work but without a moderate to strong, preferably west based, -NAO we are probably SOL. We need that -NAO to beat down the southeast ridge that has plagued us so far otherwise we are most likely looking at a continuation of the cutters we have been seeing.

[mdsnowlover]

20 minutes ago, showmethesnow said:

To me the key is the NAO. Think we have some flex with the Alaskan ridge to make things work but without a moderate to strong, preferably west based, -NAO we are probably SOL. We need that -NAO to beat down the southeast ridge that has plagued us so far otherwise we are most likely looking at a continuation of the cutters we have been seeing.

According to LC Sr Ridge is going to be with us most of the winter, but he still lists one of his storm tracks as a coastal one. Go figure.

[CAPE]

19 minutes ago, showmethesnow said:

To me the key is the NAO. Think we have some flex with the Alaskan ridge to make things work but without a moderate to strong, preferably west based, -NAO we are probably SOL. We need that -NAO to beat down the southeast ridge that has plagued us so far otherwise we are most likely looking at a continuation of the cutters we have been seeing.

SE ridge can be suppressed with -EPO/-WPO. I don't think we are screwed without a -NAO. Not to downplay the importance of a well placed, sustained -NAO. Love to see it. Just not sure I believe its very likely. Hopefully we can at least get some transient stronger ridging in the NAO region and time something, or a more persistent neutral/weakly -NAO in combination with improvement in the EPac.

[Bob Chill]

6 hours ago, mdsnowlover said:

Doesn't 10 to15 days put  us  at beginning of phase 7 MJO, or about Jan 17th??? I wouldn't be a bit surprised if your correct in your assessments.Models should start showing snowy solution around the 10 day period. Just mho based on past experience.

Where do you keep getting this MJO phase 7 from? All MJO guidance shows no real amplitude in any phase for the foreseeable future. Phase 7 sucks for us anyway as it correlates to warm in the east during DJF. 

[mdsnowlover]

18 minutes ago, Bob Chill said:

Where do you keep getting this MJO phase 7 from? All MJO guidance shows no real amplitude in any phase for the foreseeable future. Phase 7 sucks for us anyway as it correlates to warm in the east during DJF. 

Sorry  my mistake

[PhineasC]

1 hour ago, mdsnowlover said:

According to LC Sr Ridge is going to be with us most of the winter, but he still lists one of his storm tracks as a coastal one. Go figure.

LC is terrible. 

[WVclimo]

This continues to look pretty hostile for any chance at a snowy period.

 

[mdsnowlover]

11 minutes ago, PhineasC said:

LC is terrible. 

Justin Burke had a link to his winter forecast. Seems Justin thinks very highly.of him. I read the forecast out of curiosity. It's interesting that, at a past weather conference at bwi, LC was a guest speaker and did a good job.

[Bob Chill]

18 minutes ago, WVclimo said:

This continues to look pretty hostile for any chance at a snowy period.

 

It's not helping but imho it's not really bad at all. The -pna is mostly the result of lower heights downstream of the AK ridge. That ridge is the driver of the cold NA pattern. Height patterns north of us are half decent for high pressure over the top coming up a few days after NYE and beyond. The 5th has remained the beginning of a better period for at least the last 3 days. It's becoming likely that we will enter a period of BN temps after that date. The general setup being advertised is a broad gradient aligned more W-E instead of the sharp N-S pattern we've been in. This should help with less chance of a wrapped up west track and allow for more open waves to approach from the south.

 

I'm fairly optimistic we get on the board within the next 2 weeks. Could be some sort of sloppy event before the 5th but most likely nothing until after that date. Unless things fall apart I would think that our chances greatly improve in the not too distant future. We could easily be tracking our first real threat by the end of next weekend. 

[leo1000]

3 minutes ago, Bob Chill said:

It's not helping but imho it's not really bad at all. The -pna is mostly the result of lower heights downstream of the AK ridge. That ridge is the driver of the cold NA pattern. Height patterns north of us are half decent for high pressure over the top coming up a few days after NYE and beyond. The 5th has remained the beginning of a better period for at least the last 3 days. It's becoming likely that we will enter a period of BN temps after that date. The general setup being advertised is a broad gradient aligned more W-E instead of the sharp N-S pattern we've been in. This should help with less chance of a wrapped up west track and allow for more open waves to approach from the south.

 

I'm fairly optimistic we get on the board within the next 2 weeks. Could be some sort of sloppy event before the 5th but most likely nothing until after that date. Unless things fall apart I would think that our chances greatly improve in the not too distant future. We could easily be tracking our first real threat by the end of next weekend. 

It looks like it don't last long at all though. That is the problem with the way this winter is shaping up. No sustained patterns. I would rather Spring than getting a good snowstorm then it's gone than another in 10 or 15 days later. I like winters where we get one snowstorm after another. With substained cold. 

[BristowWx]

4 minutes ago, leo1000 said:

It looks like it don't last long at all though. That is the problem with the way this winter is shaping up. No sustained patterns. I would rather Spring than getting a good snowstorm then it's gone than another in 10 or 15 days later. I like winters where we get one snowstorm after another. With substained cold. 

You serious Clark?  Those winters are just a bit less than common around here.

[poolz1]

Pretty snowy in day 10-15 on the 12z gefs members.  Looks like roughly 13 want to give us some sort of hit in that timeframe.  Certainly no consensus on the actual set up though...some CAD events but I found it encouraging that miller Bs, overrunning events and even a few coastals made up a significant portion of those snowy members.  Nothing to really take away from it other than our chances of something decent increases after day 10-12.  Hopefully these trends continue....

[Thanatos_I_Am]

Pretty snowy in day 10-15 on the 12z gefs members.  Looks like roughly 13 want to give us some sort of hit in that timeframe.  Certainly no consensus on the actual set up though...some CAD events but I found it encouraging that miller Bs, overrunning events and even a few coastals made up a significant portion of those snowy members.  Nothing to really take away from it other than our chances of something decent increases after day 10-12.  Hopefully these trends continue....

Definitely a sizable jump from the 6z. The mean in DC went from about 2-2.5" to 4"-4.5"

[psuhoffman]

58 minutes ago, WVclimo said:

This continues to look pretty hostile for any chance at a snowy period.

 

That's likely something we're just going to have to overcome. It can snow in a -Pna just need most of the other factors to line up. 

[Bob Chill]

If you dig into the GEFS a little it looks like the window around the 7th is ok for something coming up from the TN valley. MLSP plots @ hr294 show the possibility of a wave attacking HP to the north of us:

 

 

24 hour mean precip 18 hours after the above panel supports the signal:

 

 

 

Some sort of overrunning or weak wave into cold hp is probably our best shot. Even with the better h5 look we're seeing, anything strong most likely won't have a hard time running west of us. We probably need to root for something weaker where HP to the north or nw wins the pressure battle and we end up in the battle zone between the 2. 

 

 

 

[WinterWxLuvr]

35 minutes ago, leo1000 said:

It looks like it don't last long at all though. That is the problem with the way this winter is shaping up. No sustained patterns. I would rather Spring than getting a good snowstorm then it's gone than another in 10 or 15 days later. I like winters where we get one snowstorm after another. With substained cold. 

You are either basing this off of 1) Long range operational runs .... huge mistake 2) long range ensembles which tend toward zonal flow far enough in time (usually) ... another mistake.

[WinterWxLuvr]

9 minutes ago, Bob Chill said:

If you dig into the GEFS a little it looks like the window around the 7th is ok for something coming up from the TN valley. MLSP plots @ hr294 show the possibility of a wave attacking HP to the north of us:

 

 

24 hour mean precip 18 hours after the above panel supports the signal:

 

 

 

Some sort of overrunning or weak wave into cold hp is probably our best shot. Even with the better h5 look we're seeing, anything strong most likely won't have a hard time running west of us. We probably need to root for something weaker where HP to the north or nw wins the pressure battle and we end up in the battle zone between the 2. 

 

 

 

I want a moisture slug into a deep CAD setup that then dryslots us as we lose temps and drags a good cold front through leaving us with concrete.

[WinterWxLuvr]

We will be tracking an event before the weekend is over.

Bob said so yesterday