December 2019 Med/Long Range Disco

[showmethesnow]

Looking over the Dec 2nd time period and you couldn't tell it by just looking at the surface but the EPS did improved. Saw an improvement at 500's. Still having the same issues as before though. Ns energy is still dropping down on top of the storm breaking down the heights. As long as we continue to see this occur this period of time is pretty much dead in the water. GEFS was pretty much a wash. Some improvements, some not so good. Same issue though, the NS energy drop.

[poolz1]

Great analysis, showme....good morning coffee reading material. Interesting looping the GEFS and watching the low heights contract to the HL and then dissolve toward the end of the run and lower heights appear to be on their way back to the Mid Lats.

Another positive result of that vortex potentially splitting is the ridging response in the Kara sea region.  Muted now but combined with an epo ridge can send the AO downhill in a hurry and would be obviously a very cold signal....just in time for the holiday run up!

[JakkelWx]

Webber says any -AO will be short lived on 33andrain.

[showmethesnow]

18 minutes ago, poolz1 said:

Great analysis, showme....good morning coffee reading material. Interesting looping the GEFS and watching the low heights contract to the HL and then dissolve toward the end of the run and lower heights appear to be on their way back to the Mid Lats.

Another positive result of that vortex potentially splitting is the ridging response in the Kara sea region.  Muted now but combined with an epo ridge can send the AO downhill in a hurry and would be obviously a very cold signal....just in time for the holiday run up!

If you look at the very end of the run you see the possibility of ridge bridging across the pole between the EPO/NAO, EPO/Central Russia, NAO/Russia or even possibly all three. Not a bad place to be for our winter chances. Of course this look will probably be gone the next run. 

[anotherman]

Just my opinion, but anyone who uses the models to make any sort of forecast over 7 days must be out of their minds.  The swings have been wild.

[CAPE]

42 minutes ago, JakkelWx said:

Webber says any -AO will be short lived on 33andrain.

Yes. Of course he said that.

He may be right, but he is nothing if not predictable.

[CAPE]

6 minutes ago, anotherman said:

Just my opinion, but anyone who uses the models to make any sort of forecast over 7 days must be out of their minds.  The swings have been wild.

Who is doing that?

[anotherman]

Just now, C.A.P.E. said:

Who is doing that?

No one in particular here, but I just have to laugh when people get into arguments about the long range, like this guy everyone keeps posting about (Webb).  It changes drastically every 6 hours.

[mappy]

I'm suggesting we move talks of Webb to banter. 

[Bob Chill]

2 hours ago, anotherman said:

No one in particular here, but I just have to laugh when people get into arguments about the long range, like this guy everyone keeps posting about (Webb).  It changes drastically every 6 hours.

Sensible wx (more specifically individual threats) has no skill out in time. Where the line of believable vs unbelievable is drawn is up to the individual. If you want to believe a d7+ op with a snow event then do it. Do it enough and you'll stop doing it. lol. However, large scale hemispheric pattern drivers like the pac jet, AO, EPO, and other major drivers can be predicted with some skill way out in time. Sometimes 2 weeks and beyond. Sometimes months at a time. I think it's completely fine (and healthy) to discuss the big picture and what it generally means. I'm sure most agree there. When I post about long range stuff I'm seeing it from only 1 perspective... is it a shutout or not and why. Right now I'm looking for a real threat window to emerge and I'll certainly post about it if/when I see something. Even if it's 2 weeks away. 

I'll agree that the real disasterous look is backing off but I still don't like the overall big picture for snow chances in these parts on any piece of guidance right now. If the +AO is in fact temporary and things start to shuffle back to something decent then it will happen at a time when it's not extremely hard to snow here. Outside of a flukey flawed lucky event, I don't expect much tracking for a while. The first week of Dec could offer something flukey/flawed but overall it's not a good looking period. Beyond that looks worse. Beyond that is starting to look less worse but not close.

[WxUSAF]

Starting to think we should be paying less attention to the WAA front end of next weekends storm and more attention to squeezing some snow out of the ULL as it moves past overnight Sunday into Monday. 

[yoda]

9 minutes ago, WxUSAF said:

Starting to think we should be paying less attention to the WAA front end of next weekends storm and more attention to squeezing some snow out of the ULL as it moves past overnight Sunday into Monday. 

Def agree... don't bother looking to the NE either for next weekend on the 12z GFS

12z GFS has the mountains eat up any chance at some ULL love though

[yoda]

Meh

[Bob Chill]

42 minutes ago, WxUSAF said:

Starting to think we should be paying less attention to the WAA front end of next weekends storm and more attention to squeezing some snow out of the ULL as it moves past overnight Sunday into Monday. 

Yea, it's a pretty powerful ULL as it crosses the region but taking an unusual course SE as it moves from OH to off the coast. Move the center of this bowling ball 150-200 mi south somewhere around ROA and the best dynamics/instability will cross by in a pretty sweet spot. Convective style snow from a closed ULL is one of my personal faves. Big omegas = big dendrites = high ratio pounding = weenie party. Even if short lived. 

[WinterWxLuvr]

My take on the gfs is that it’s active. Keep it active and we will score in time. It’s very early. I am very optimistic 

[yoda]

3 minutes ago, Bob Chill said:

Yea, it's a pretty powerful ULL as it crosses the region but taking an unusual course SE as it moves from OH to off the coast. Move the center of this bowling ball 150-200 mi south somewhere around ROA and the best dynamics/instability will cross by in a pretty sweet spot. Convective style snow from a closed ULL is one of my personal faves. Big omegas = big dendrites = high ratio pounding = weenie party. Even if short lived. 

Problem this go around is the mountains per the 12z GFS eat up all the precip and barely gets even flurries over to us... not sure it would happen that way but its what it shows even with the powerful ULL moving through us

[frd]

1 minute ago, Bob Chill said:

Yea, it's a pretty powerful ULL as it crosses the region but taking an unusual course SE as it moves from OH to off the coast. Move the center of this bowling ball 150-200 mi south somewhere around ROA and the best dynamics/instability will cross by in a pretty sweet spot. Convective style snow from a closed ULL is one of my personal faves. Big omegas = big dendrites = high ratio pounding = weenie party. Even if short lived.

Bob, if the Atlantic side improves, in terms of the positioning of the block,  do you think we see the ULL in future runs dive further South and Southeast? 

Looks like the Pac is OK in a general sense, but the Atlantic is lacking.  Move the block further South and a bit West and could see some improvements. 

So far ahead to have any confidence I would imagine at this point.  There seems to be a lot of chaos going on up  North, lots of moving parts you could say. 

The funniest thing of all is this entire concept is built upon the concept the GFS at 150 hours, has any clue at 500 mb.     

[CAPE]

CMC looks interesting for the 5th. Phases a piece of Pac energy with NS energy and pops a low off the coast of NC. Nice shield of light to moderate snow for the area verbatim.

[Bob Chill]

20 minutes ago, frd said:

Bob, if the Atlantic side improves, in terms of the positioning of the block,  do you think we see the ULL in future runs dive further South and Southeast? 

Looks like the Pac is OK in a general sense, but the Atlantic is lacking.  Move the block further South and a bit West and could see some improvements. 

So far ahead to have any confidence I would imagine at this point.  There seems to be a lot of chaos going on up  North, lots of moving parts you could say. 

The funniest thing of all is this entire concept is built upon the concept the GFS at 150 hours, has any clue at 500 mb.     

It's all about ridging above the closed ULL and the spacing with the 50/50. It's certainly possible for a further south track but even as is the track is defying the atmosphere. Closed ULLs that track over Des Moines rarely work out here and the typical trend is north for these features as leads shorten. This is d5 so plenty can change. Just root for the bowling ball to be weaker and further south through the midwest. Faster would be better too. 

 

It's an interesting setup for sure and I'm def watching it. I just don't like the odds here. The ULL is very strong in the midwest and it's going to try it's hardest to push against ridging and confluence. I remember the Feb 2015 storm (superbowl weekend?) that models all had a good track in the med range but guidance kept ticking north as leads shortened and it ended up being a whiff. IIRC, that ULL tracked right over Indianapolis. This one is further north as is. But there's also a blocking ridge to the north and pretty strong confluence to the east. The faster the ull tracks across the conus the better. 

 

 

[psuhoffman]

Gefs looks less awful heading into mid December. 

[WxUSAF]

The trend for the LR to look far from catastrophic continues on the 12z GEFS. The super positive AO is gone, with it probably neutral or weakly positive by the 3rd or so. Still looks to me like there’s a lot of spread after the 3rd or 4th.

[Bob Chill]

12 minutes ago, WxUSAF said:

The trend for the LR to look far from catastrophic continues on the 12z GEFS. The super positive AO is gone, with it probably neutral or weakly positive by the 3rd or so. Still looks to me like there’s a lot of spread after the 3rd or 4th.

Looks familiar... kinda like the base state in 13-14. lol.  -EPO/+AO/WAR showing up. If that's as "bad" as it gets then at least we're not in a shutout pattern. Checking through the GEFS it seems like there's 2 camps down the line. One camp has a GOA trough, +AO, pac air regime and the other camp keeps things more amplified with a +PNA/-EPO/trough in the east.

All members agree on progressive flow down the line. My total WAG is we end up seeing both camps. As the AO goes positive we'll have a period of zonal pac air mild followed by the PNA ridge going up and trough returning to the east. 

I'm totally good with a mild/crap period as long as it's short and morphs into something that can at least keep us in the game. GEFS/EPS are both trending away from epic disaster. 

[WxUSAF]

Snow on the euro!! 

hr132 has snow for points N and E of DC and continues at 138!  Weenie maps have 4” for Baltimore! Lol

[pasnownut]

28 minutes ago, Bob Chill said:

It's all about ridging above the closed ULL and the spacing with the 50/50. It's certainly possible for a further south track but even as is the track is defying the atmosphere. Closed ULLs that track over Des Moines rarely work out here and the typical trend is north for these features as leads shorten. This is d5 so plenty can change. Just root for the bowling ball to be weaker and further south through the midwest. Faster would be better too. 

 

It's an interesting setup for sure and I'm def watching it. I just don't like the odds here. The ULL is very strong in the midwest and it's going to try it's hardest to push against ridging and confluence. I remember the Feb 2015 storm (superbowl weekend?) that models all had a good track in the med range but guidance kept ticking north as leads shortened and it ended up being a whiff. IIRC, that ULL tracked right over Indianapolis. This one is further north as is. But there's also a blocking ridge to the north and pretty strong confluence to the east. The faster the ull tracks across the conus the better. 

 

 

If one looks at the potential weekend event on the GFS, there's more than a little bouncing around on the surface low evolution, and it seems plausable that as we near and see a better track that the potential for the ULL to catch the surface as it really slows once it hits the coast.  Get that surface low to ride a little further south and it could be a nice little surprise IMO.

[midatlanticweather]

10 minutes ago, Bob Chill said:

Looks familiar... kinda like the base state in 13-14. lol.  -EPO/+AO/WAR showing up. If that's as "bad" as it gets then at least we're not in a shutout pattern. Checking through the GEFS it seems like there's 2 camps down the line. One camp has a GOA trough, +AO, pac air regime and the other camp keeps things more amplified with a +PNA/-EPO/trough in the east.

All members agree on progressive flow down the line. My total WAG is we end up seeing both camps. As the AO goes positive we'll have a period of zonal pac air mild followed by the PNA ridge going up and trough returning to the east. 

I'm totally good with a mild/crap period as long as it's short and morphs into something that can at least keep us in the game. GEFS/EPS are both trending away from epic disaster. 

13/14 had another wild pattern as I remember the best snow track shifting south. That was such a strange memory for that year. I think I remember one time the track went from Maine to south of us delivering central VA the goods. That was such a wild year, as many were good for our backyard. 

[pasnownut]

34 minutes ago, psuhoffman said:

Gefs looks less awful heading into mid December. 

Yeah it looks once beyond the 12/6 timeframe that the PAC ridge/ trough East seems to stay their right through the end.  Doesn't appear crazy cold, but if timed right, cold enough to get a festive feel in the air.  Tellies really dont really support what the GEFS is showing (in my mind anyway - mostly PNA), but enough neutrals to say....ok...maybe.

 

[WxUSAF]

Euro gets it done just by slightly strengthening that high to our north and also starting the coastal transfer earlier to our south. Like the gfs, euro takes the ULL basically overhead and takes the precip with it through central VA.

[Amped]

2 minutes ago, WxUSAF said:

Euro gets it done just by slightly strengthening that high to our north and also starting the coastal transfer earlier to our south. Like the gfs, euro takes the ULL basically overhead and takes the precip with it through central VA.

Im impressed that a monster bowling ball actually loses latitude between the plains and the east coast. Think of what could have been if it started weaker and further south.

[WinterWxLuvr]

3 minutes ago, Amped said:

Im impressed that a monster bowling ball actually loses latitude between the plains and the east coast. Think of what could have been if it started weaker and further south.

It still might. This is still a good distance into the future.

[WVclimo]

12Z Euro starts the weekend event as some snow in my yard, transitioning to a prolonged period of 31-32 degree FZRA,  A few degrees colder than progged could make a much bigger impact.