December Med/Long Range Discussion

[ErinInTheSky]

12 minutes ago, yoda said:

I reopened it two weeks ago

I've had a wxbell account for forever. Living in Louisiana I always cancel it after hurricane season but now I have an excuse to keep it going.

[Round Hill WX]

The period between 12/12 through 12/17 is the time period to start watching for a southern jet system to develop as the deep eastern trough moves out. 

[mappy]

this cold shot coming next week continues to look impressive 

 

[North Balti Zen]

14 hours ago, das said:

Cherry picking the last two months to validate a seasonal tool is nearly using anecdote to prove your point.  The actual data tells another story.  Verification scores for our area from their own interface for the last 12 months ending yesterday tells the actual story.  They are just a smidge to the right of climatology.  Like 0.1 standard deviations to the right:

Merryfield, et. al., got funding and spent 6 years building that thing, it's been in PROD since 2012 and that's the result?  Yikes, especially since it was funded to solve poor long-lead forecasting issues in winter on the CA west coast and summer in eastern CA.

 

Oh my.

[Wonderdog]

6z GFS run continues to show a few winter events including CAD and the white stuff. Cold air still on the way!

[WxUSAF]

Looks like our first legit threat window is probably the 11th-12th. Which is sad because I'll be gone for it, but good since it's usually the storm after the storm that produces so I'll be back for the real threat a few days later 

But in seriousness, seems like a s/w is coming into the plains with confluence still to our north thanks to the big cutter on the 9th and plenty of cold air around. 0z EPS seems a bit weaker on the wave relative to 12z. 6z GFS has a storm in that window but the GL low screws up temps. 

[Superstorm]

Looks like our first legit threat window is probably the 11th-12th. Which is sad because I'll be gone for it, but good since it's usually the storm after the storm that produces so I'll be back for the real threat a few days later 

But in seriousness, seems like a s/w is coming into the plains with confluence still to our north thanks to the big cutter on the 9th and plenty of cold air around. 0z EPS seems a bit weaker on the wave relative to 12z. 6z GFS has a storm in that window but the GL low screws up temps. 

Doesn't the Great Lakes low always screw things up?


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[mappy]

8 minutes ago, Superstorm said:

Doesn't the Great Lakes low always screw things up?


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pretty much - cold air gets wrapped up in the low, thus we tend to get the warmer temps out ahead of it. 

[Round Hill WX]

8 hours ago, Round Hill WX said:

The period between 12/12 through 12/17 is the time period to start watching for a southern jet system to develop as the deep eastern trough moves out. 

6z GEFS likes the same time frame. I think we will have our first one or two frozen chances here. We'll see what happens beyond that as the Aleutian low wants to reestablish itself and the pac jet cranks up with a zonal US flow.    

[ErinInTheSky]

28 minutes ago, WxUSAF said:

Looks like our first legit threat window is probably the 11th-12th. Which is sad because I'll be gone for it, but good since it's usually the storm after the storm that produces so I'll be back for the real threat a few days later 

But in seriousness, seems like a s/w is coming into the plains with confluence still to our north thanks to the big cutter on the 9th and plenty of cold air around. 0z EPS seems a bit weaker on the wave relative to 12z. 6z GFS has a storm in that window but the GL low screws up temps. 

That is literally the day I'm moving up so if it happens you can thank me.

[poolz1]

Pretty stark difference between the GEFS and EPS with regard to the Aleutian ridge.  EPS holds this feature and makes it a dominant player whereas the GEFS want to break it down in short order.  I'd lean EPS...but, a little uncharted territory with the upgrade I guess.  

[Bob Chill]

11 minutes ago, poolz1 said:

Pretty stark difference between the GEFS and EPS with regard to the Aleutian ridge.  EPS holds this feature and makes it a dominant player whereas the GEFS want to break it down in short order.  I'd lean EPS...but, a little uncharted territory with the upgrade I guess.  

Quite the divergence in evolution with the closed ridge on the AK side of the Arctic. If history tells us anything, it's more typical for stubborn features to prevail longer than modeled. Gefs could be right but I have reservations believing a large closed ridge along with fairly expansive higher heights gets replaced so quickly with an equally large area of below normal heights. 

Another thing that seems pretty important to keep an eye on is the euro ens trended even stronger with a building -nao d10-15 with the best look at the end of the run. Must be a good bit of consensus to have that kind of look. If Dec is going to really be a winter month as a whole, that's an important part of it. 

 

[WinterWxLuvr]

2 hours ago, losetoa6 said:

Euro has been persistent in showing some minor snow accum. for the N/W burbs for Tuesday - with 30s for highs.  It even shows possible flakes Sunday night. Eps does give some support  for Tuesday. Secondary low placement looks good and the Ohio primary low looks to be weaker. See if it continues the theme on todays run.

The Euro and GFS aren't very far off in their forecasts.  The Euro is colder, which is unusual, because it has a high in a better position over Quebec.

I still don't think we can write this off (a little front end slop at worst).  Of course, I may be singing a different tune in about 4 hours.

[Bob Chill]

1 hour ago, WxUSAF said:

Looks like our first legit threat window is probably the 11th-12th. Which is sad because I'll be gone for it, but good since it's usually the storm after the storm that produces so I'll be back for the real threat a few days later 

But in seriousness, seems like a s/w is coming into the plains with confluence still to our north thanks to the big cutter on the 9th and plenty of cold air around. 0z EPS seems a bit weaker on the wave relative to 12z. 6z GFS has a storm in that window but the GL low screws up temps. 

Yea, even though we get a pretty impressive air mass in advance, the only mechanism to hold it in place is a departing 50/50. HP along the east coast doesn't look to be in a good spot for now for an all snow even assuming we get anything. Kinda has the look of a more typical snow to mix. 

 

We could pull the handle and get triple 7's and have confluence force the shortwave under us but we have quite a few days to go before getting a handle on anything. 

 

[WxUSAF]

14 minutes ago, Bob Chill said:

Yea, even though we get a pretty impressive air mass in advance, the only mechanism to hold it in place is a departing 50/50. HP along the east coast doesn't look to be in a good spot for now for an all snow even assuming we get anything. Kinda has the look of a more typical snow to mix. 

 

We could pull the handle and get triple 7's and have confluence force the shortwave under us but we have quite a few days to go before getting a handle on anything. 

 

Based on the progged long wave pattern, I would think we get two or three chances in the week starting on the 10th/11th before something gets shuffled or we go through a reload period. If the advertised pattern does materialize, I think we all get some snow before the 20th.

[poolz1]

5 minutes ago, Bob Chill said:

Quite the divergence in evolution with the closed ridge on the AK side of the Arctic. If history tells us anything, it's more typical for stubborn features to prevail longer than modeled. Gefs could be right but I have reservations believing a large closed ridge along with fairly expansive higher heights gets replaced so quickly with an equally large area of below normal heights. 

Another thing that seems pretty important to keep an eye on is the euro ens trended even stronger with a building -nao d10-15 with the best look at the end of the run. Must be a good bit of consensus to have that kind of look. If Dec is going to really be a winter month as a whole, that's an important part of it. 

 

I recall you saying something similar a few days ago when the models were trying to break down that ridge in the LR.  Remembering the eastern red paint bomb last Dec. Models would constantly try to break it down in the LR and we all know how that turned out.  

[mappy]

really hoping this cold works out

 

[Bob Chill]

4 minutes ago, poolz1 said:

I recall you saying something similar a few days ago when the models were trying to break down that ridge in the LR.  Remembering the eastern red paint bomb last Dec. Models would constantly try to break it down in the LR and we all know how that turned out.  

JFM 2014 was no different with the -epo. Models canceled winter in the long range multiple times but it kept coming back over and over. Not a good apples to apples here though. We are in the transition month unlike JF where things are more established and something like a closed ridge in the arctic is only a tiny portion of the hemishperic pattern. Last Dec was solidly embedded in the longwave pattern. Man it was ugly. And depressing...lol

[Bob Chill]

15 minutes ago, WxUSAF said:

Based on the progged long wave pattern, I would think we get two or three chances in the week starting on the 10th/11th before something gets shuffled or we go through a reload period. If the advertised pattern does materialize, I think we all get some snow before the 20th.

Totally agree. It's not a one and done window hopfully. Maybe the best is yet to come...you probably approve of this map...Davis Straight gettin all kinky and hot an bothered on the western side of the arctic. Porn...lol

 

 

 

[WxUSAF]

8 minutes ago, Bob Chill said:

Totally agree. It's not a one and done window hopfully. Maybe the best is yet to come...you probably approve of this map...Davis Straight gettin all kinky and hot an bothered on the western side of the arctic. Porn...lol

 

 

 

Oh my, yeah. Nothing wrong with that look. That would tend to shut off the cutter risk as well. I think things start getting real for us by early next week as far as tracking.

[psuhoffman]

1 hour ago, Bob Chill said:

Quite the divergence in evolution with the closed ridge on the AK side of the Arctic. If history tells us anything, it's more typical for stubborn features to prevail longer than modeled. Gefs could be right but I have reservations believing a large closed ridge along with fairly expansive higher heights gets replaced so quickly with an equally large area of below normal heights. 

Another thing that seems pretty important to keep an eye on is the euro ens trended even stronger with a building -nao d10-15 with the best look at the end of the run. Must be a good bit of consensus to have that kind of look. If Dec is going to really be a winter month as a whole, that's an important part of it. 

 

That feature on the EPS has me a little more interested now.  I think the cold is coming, but minus a better look to our north I suspect it would be mostly transient shots without much threat of a significant winter event.  Of course in 2013-14 and 14-15 we scored several times with very marginal patterns but I don't think we can go to that well too often.  Better blocking and suddenly our prospects improve dramatically.  

Edit: I am strictly talking about significant event threats, we could easily score some smaller events either mixed bag or a weak system that stays under us in the pattern without blocking.  As you all know I am a bit of a big ticket item chaser.  

[Bob Chill]

15 minutes ago, WxUSAF said:

Oh my, yeah. Nothing wrong with that look. That would tend to shut off the cutter risk as well. I think things start getting real for us by early next week as far as tracking.

 

We've been seeing some looks off and on with the AK ridging connecting with ridging on the other side of the globe. The last few eps runs have been trending more in that direction while the GEFS is almost dropping the idea completely. CMC ens kinda split the difference. I don't like divergence regardless of which ensemble suite is showing the better look.

The NAO is slippery like a snake. Long leads struggle terribly with it. BUT.... if we do get a real -NAO going then we're probably in for a treat. Second half of Dec -NAO's are pretty nice to our area in general. 2010 won't change my mind about that either. haha 

[Bob Chill]

17 minutes ago, psuhoffman said:

That feature on the EPS has me a little more interested now.  I think the cold is coming, but minus a better look to our north I suspect it would be mostly transient shots without much threat of a significant winter event.  Of course in 2013-14 and 14-15 we scored several times with very marginal patterns but I don't think we can go to that well too often.  Better blocking and suddenly our prospects improve dramatically.  

Edit: I am strictly talking about significant event threats, we could easily score some smaller events either mixed bag or a weak system that stays under us in the pattern without blocking.  As you all know I am a bit of a big ticket item chaser.  

The 0z run was definitely the strongest signal so far. But that's only slightly encouraging. We've had too many good long lead looks vaporize to buy in. If there is a big red blob in the medium range sitting over GL and Davis Straight a week from now we may have a shot at a meaningful storm. I wouldn't mind getting on the board in the next week or 2 though. An inch or 2 would be just fine. 

[WinterWxLuvr]

GFS didn't kill it.  It's a long shot, but a stronger high to the ne and we might see a little something on Tues.

 

[psuhoffman]

45 minutes ago, Bob Chill said:

The 0z run was definitely the strongest signal so far. But that's only slightly encouraging. We've had too many good long lead looks vaporize to buy in. If there is a big red blob in the medium range sitting over GL and Davis Straight a week from now we may have a shot at a meaningful storm. I wouldn't mind getting on the board in the next week or 2 though. An inch or 2 would be just fine. 

Oh there is nothing wrong with just getting on the board, and it is always nice just to have a little snow around the holiday time period.  On the other hand this is a year where some of the analogs were skewed early season for snowfall.  We never know when the "windows" of opportunity are.  Remember in 2005/6 we had a good period early with several winter events and then the rest of the winter was pretty much atrocious except for that one hail mary thread the needle fluke storm in February.   In 2011-12 I got an 8" snow in October and then nothing of any significance the entire rest of the winter.   I guess if we get a small event in december and nothing more thats fine assuming we get something better down the road in January and February, I just never take that for granted.  I am always looking to score now since later isn't a sure thing.

[yoda]

12 minutes ago, WinterWxLuvr said:

GFS didn't kill it.  It's a long shot, but a stronger high to the ne and we might see a little something on Tues.

 

The high to the NE needs to be like 10mb stronger for anything on Tuesday

[yoda]

Toasty 850s at 162 and 168

[WinterWxLuvr]

Just now, yoda said:

The high to the NE needs to be like 10mb stronger for anything on Tuesday

I'm thinking 1030 would do it.  And it needs to be a little further south.

[Bob Chill]

2 minutes ago, yoda said:

The high to the NE needs to be like 10mb stronger for anything on Tuesday

It's not really the high to the north that's causing the problem. It's the hp off the SE coast. It's on all models. Southerly 850's well in front of the low coming up is a big flag and this is only @ 72hrs. Not sure how much can change there. I would think the HP to the north would need be exceptionally strong to offset the return flow. 

 

[WinterWxLuvr]

Just now, Bob Chill said:

It's not really the high to the north that's causing the problem. It's the hp off the SE coast. It's on all models. Southerly 850's well in front of the low coming up is a big flag and this is only @ 72hrs. Not sure how much can change there. I would think the HP to the north would need be exceptionally strong to offset the return flow. 

 

This isn't the time frame I'm talking about.  I'm looking at hour 102+.