December 2019 Med/Long Range Disco

[WxUSAF]

4 minutes ago, Bob Chill said:

Gfs is pretty much the same as the 12z euro

Well it is until Sunday, then still does the capture and deform. Just a bit farther NE then 12z.

 

Seems to me the front end of the storm is getting pretty well narrowed on options (although I still expect we’ll end up on the outside of WAA snow), but the back end and coastal transfer is poorly constrained.

[Bob Chill]

3 minutes ago, WxUSAF said:

I like the timing of this run. WAA snow/sleet comes in after dark Saturday. Better chance to get on the board. 

No doubt. The only way I'd be bummed about an inch or so of snow would be if all the models give me 4+ 24 hours before the event. 

[CAPE]

Still liking the GFS getting my yard in on some deform band action with the coastal. 

[WxUSAF]

1 minute ago, Bob Chill said:

No doubt. The only way I'd be bummed about an inch or so of snow would be if all the models give me 4+ 24 hours before the event. 

I’d be thrilled with 1” of snow. I’m still skeptical, but I’m starting to believe it’s possible. Let’s see a run like this on Thursday’s happy hour when we’re all drunk and fat and I’ll get my hopes up.

[Bob Chill]

7 minutes ago, frd said:

Some mets are looking for their return this winter. As mentioned a while back,  some pros and certain seasonal winter forecasts have mentioned better odds this winter of Alberta clippers, etc., would love a Manitoba Mauler that cripples the Northern Mid Atlantic. 

As for where have they gone, seems since we had that massive warming in the Pac a few years back , it has been sort of blah, just speculation really.    

We had quite a few clipper type systems in 13/14 and 14/15. Somewhere in the range of 5-10 unless my memory is completely failing. Which is possible. 

Nina's in general have clippers every year too. I don't think there's been a lack since 2010. We've had a hard time getting the northern stream to dig under us the last 2 years though. 

[Bob Chill]

At least if we fail this weekend the gfs says maybe the storm after the storm is the one

[CAPE]

6 minutes ago, Bob Chill said:

We had quite a few clipper type systems in 13/14 and 14/15. Somewhere in the range of 5-10 unless my memory is completely failing. Which is possible. 

Nina's in general have clippers every year too. I don't think there's been a lack since 2010. We've had a hard time getting the northern stream to dig under us the last 2 years though. 

Yeah I miss a good clipper. They can be fun, are pretty simple, but can be a challenge to get one to  track to our south. Been few and far between in recent winters. If this winter ends up being ENSO neutral and EPO ridge dominant we could see a legit clipper or 2 track underneath with some decent coastal enhancement.

[poolz1]

Dec 5th coming in hot! 

[WxUSAF]

Just now, poolz1 said:

Dec 5th coming in hot! 

Happy hour offering 2-for-1 specials on the @showmethesnow storm. Or is it my storm? I said I liked 3-5 December like a week ago.

[CAPE]

Just now, poolz1 said:

Dec 5th coming in hot! 

I have been liking this period for a while. The storm after the storm everyone is focusing on.

[WEATHER53]

High pressure will consistently perform well this winter. That means sometime suppressive but sometimes good. We will have very few 33-35 and rain because of high being too weak.

[CAPE]

Just now, WxUSAF said:

Happy hour offering 2-for-1 specials on the @showmethesnow storm. Or is it my storm? I said I liked 3-5 December like a week ago.

Could be mine too, but I suppose it is really the  @leesburg 04 storm.

[aldie 22]

1 minute ago, C.A.P.E. said:

Could be mine too, but I suppose it is really the  @leesburg 04 storm.

I forgot to copyright it 

[clskinsfan]

Hi Res GFS likes the WAA for NW of town. A couple inches of slop.

[osfan24]

GFS also needs trough to get at least neutral to negative sooner for us to get in on the coastal. It's a strong storm sitting off the coast initially but precip isn't all that great because trough is still too positively titled.

[Bob Chill]

18z gfs has like 5 50/50s in 2 weeks. Lol. The one 10 days down the line pops a -nao. I'm going to start paying more attention to the 50/50 area because if LPs hanging out around there becomes a persistent feature this winter then good things will happen by default.

A 50/50 is the ultimate block for MA snow events. Has more influence on storm track than the AO or NAO. I highly recommend looping the NA or NH 18z gfs h5 and mslp anomaly panels and check it out. We can go entire years without a legit 50/50 and the gfs is throwing them out there like rice at a wedding 

[frd]

17 minutes ago, Bob Chill said:

A 50/50 is the ultimate block for MA snow events.

The 50/50 is so important for our area it is featured among DT's  checklist of MECS. 

I know he loves focusing on the QBO, but when he goes down his list of key features needed for the big ones, the 50/50 is always talked about in detail. 

The throwing rice at a wedding thing was a good one ......   I love these HH runs ! 

 

[CAPE]

2 minutes ago, frd said:

The 50/50 is so important for our area it is featured among DT's  checklist of MECS. 

I know he loves focusing on the QBO, but when he goes down his list of key features needed for the big ones, the 50/50 is always talked about in detail. 

The throwing rice at a wedding thing was a good one ......   I love these HH runs ! 

 

A 50-50 low really goes hand in hand with a -NAO though. Without the block, a vortex in the 50-50 region is mostly a transient feature, which is ok, but not the same as having a low trapped under a legit blocking ridge in the NA.

[psuhoffman]

29 minutes ago, Bob Chill said:

18z gfs has like 5 50/50s in 2 weeks. Lol. The one 10 days down the line pops a -nao. I'm going to start paying more attention to the 50/50 area because if LPs hanging out around there becomes a persistent feature this winter then good things will happen by default.

A 50/50 is the ultimate block for MA snow events. Has more influence on storm track than the AO or NAO. I highly recommend looping the NA or NH 18z gfs h5 and mslp anomaly panels and check it out. We can go entire years without a legit 50/50 and the gfs is throwing them out there like rice at a wedding 

There are several things I like seeing right now. The mjo being muted before it gets to the maritime continent. The sst in the north Pac. The tendency for troughs to kick out of the west quickly. But the one that I am most thrilled with is that almost every system this year is amplifying through the 50/50 space. The last few years systems would either get squashed or pull up into Quebec and the WAR would hold. This year everything else up a 50/50. Keep that up and it’s a ticking time bomb, only a matter of time before something goes off. 

[psuhoffman]

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

A 50-50 low really goes hand in hand with a -NAO though. Without the block, a vortex in the 50-50 region is mostly a transient feature, which is ok, but not the same as having a low trapped under a legit blocking ridge in the NA.

It’s not as good in that they are temporary features and so the window is shorter. But if we get a year where everything wants to amplify through that domain it will create multiple opportunities to time something up. We will likely get some hits. It wouldn’t be 2010 epicness without a stout block but that tendency could be the difference between a sub par year and a pretty good one. 

[frd]

Just now, psuhoffman said:

But the one that I am most thrilled with is that almost every system this year is amplifying through the 50/50 space. The last few years systems would either get squashed or pull up into Quebec and the WAR would hold. This year everything else up a 50/50. Keep that up and it’s a ticking time bomb, only a matter of time before something goes off.

Thought I read this might be related to the SST profile up there. 

Over the summer when we had the periodic bouts of -NAO it was mentioned the cold pool was responsible. 

Do you have any thought on it  psu?   Secondary guess would be wave breaking, but not sure.  

And yeah, love seeing this.  

 

[psuhoffman]

Gefs starting to look like the euro heading towards mid December. 

[frd]

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

A 50-50 low really goes hand in hand with a -NAO though. Without the block, a vortex in the 50-50 region is mostly a transient feature, which is ok, but not the same as having a low trapped under a legit blocking ridge in the NA.

Very true, it has been so long that we have had all the players working for us in our favor. ( ie. the 50/50 or a -NAO leading to a HA event, etc. )  I miss the Big Dogs !  The atmosphere may want to cooperate this winter. 

[frd]

Just now, psuhoffman said:

Gefs starting to look like the euro heading towards mid December. 

Wish HM would pop in and chime in on that map, from a HL point of view. . I might want to guess and say it looks at 500 as a precursor pattern for further vortex weakening.  

[CAPE]

Just now, psuhoffman said:

It’s not as good in that they are temporary features and so the window is shorter. But if we get a year where everything wants to amplify through that domain it will create multiple opportunities to time something up. We will likely get some hits. It wouldn’t be 2010 epicness without a stout block but that tendency could be the difference between a sub par year and a pretty good one. 

Yeah that's my point- vortices rotating through the 50-50 region absent a NA block are thread the needle deals. I will take that over having higher heights in that region every time though for sure. But no way in  hell I believe that is the ultimate/ better or equivalent to having a sustained -AO/NAO.

[Bob Chill]

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

A 50-50 low really goes hand in hand with a -NAO though. Without the block, a vortex in the 50-50 region is mostly a transient feature, which is ok, but not the same as having a low trapped under a legit blocking ridge in the NA.

Yep, best setup is always a -nao with a 50/50. Even in progressive flow a transient 50/50 can still help block an upstream shortwave from scooting north of us. Looking at the loops of multiple recent gfs runs there's a recurring theme of tracking pretty strong LPs through the 50/50 space. Oh please please please let this be the dominant storm track this season...

6 minutes ago, psuhoffman said:

There are several things I like seeing right now. The mjo being muted before it gets to the maritime continent. The sst in the north Pac. The tendency for troughs to kick out of the west quickly. But the one that I am most thrilled with is that almost every system this year is amplifying through the 50/50 space. The last few years systems would either get squashed or pull up into Quebec and the WAR would hold. This year everything else up a 50/50. Keep that up and it’s a ticking time bomb, only a matter of time before something goes 

Agree 100%. We're seeing a lot of features we want working in unison. Started early this month and isn't letting up. Ens agree on a +pna building during the first week of Dec. If flow remains active and doesn't dry up we'll be in the game for a warning level event and not dealing with jacked up flawed light events. 

[Bob Chill]

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

 But no way in  hell I believe that is the ultimate/ better or equivalent to having a sustained -AO/NAO.

I wasn't implying that a transient 50/50 is better than a -ao or nao or anything like that. I was just saying that 50/50 has the most direct impact in keeping upstream waves from cutting west of us. We get west tracks with a -ao/nao and it's nearly always because there was no 50/50 to block a storm from gaining too much latitude. Most of our big events in +ao/nao patterns are lucky timing with a 50/50 on the move. 

Another thing I've been noticing lately is wave spacing has been really favorable. Storms are getting wound up without getting beat up, sheared, or tugged around by crowded flow. 

[CAPE]

10 minutes ago, Bob Chill said:

Yep, best setup is always a -nao with a 50/50. Even in progressive flow a transient 50/50 can still help block an upstream shortwave from scooting north of us. Looking at the loops of multiple recent gfs runs there's a recurring theme of tracking pretty strong LPs through the 50/50 space. Oh please please please let this be the dominant storm track this season...

 

Agree with this. I probably misinterpreted your post. I thought you were suggesting a 50-50 vortex (transient or otherwise) was more important than having a -AO and or -NAO. A -NAO/50-50 combo is absolutely the ULTIMATE block imo to force a favorable storm track for MA snow events.

[nj2va]

While this is focused on “major snow events” in the Philly region, I found it a quick, easy read on the major factors to look for in our area (50/50, NAO, EPO, etc).  DT helped put it together based on the credits.  Some of the specifics for things that work well for them aren’t the case here but still a handy read.  You’ll notice they use images from the KU textbook.

https://www.abington.k12.pa.us/teachers/hurmms/Majorsnowstormchecklist_files/Stormchecklist.ppt

[CAPE]

18 minutes ago, nj2va said:

While this is focused on “major snow events” in the Philly region, I found it a quick, easy read on the major factors to look for in our area (50/50, NAO, EPO, etc).  DT helped put it together based on the credits.  Some of the specifics for things that work well for them aren’t the case here but still a handy read.  You’ll notice they use images from the KU textbook.

https://www.abington.k12.pa.us/teachers/hurmms/Majorsnowstormchecklist_files/Stormchecklist.ppt

I have seen that before. Pretty good presentation.