December Med/Long Range Discussion

[WinterWxLuvr]

3 minutes ago, showmethesnow said:

Cutters instead of whiffs? Warm/wet instead instead of cold/dry? I'll take option C.

You are forgetting that cold air pushes from the west and is also hard to dislodge from the east.  If you want winter weather, you have to have precip.

Yes you flirt with cutters, but at least you have a chance.  Trough on top of us, no chance.

[stormtracker]

7 hours ago, mdsnowlover said:

no snow on either gfs or euro till at least the 15th probably longer than that, but lots of rain, enjoy the soggy conditions, waiting for this cold dec of JB to develop, and snow,  lol!!! west track predominates  !!

Stop posting. 

[mdsnowlover]

6 hours ago, psuhoffman said:

.

[Bob Chill]

8 minutes ago, WinterWxLuvr said:

You are forgetting that cold air pushes from the west and is also hard to dislodge from the east.  If you want winter weather, you have to have precip.

Yes you flirt with cutters, but at least you have a chance.  Trough on top of us, no chance.

The thing about ensemble troughs that show relatively static isn't really how it works in real time. Everything is always on the move. The burning question is whether we can line something up while things are moving. Right now anything organized is going to cut. Trough axis hasn't been favorable and without a more significant block down stream, anything organized in the northern stream is going to have a much easier time going west of us. I agree that it doesn't mean it can't work out on the front end but right now models are keeping spacing far enough apart that air masses are pretty stale by the time precip arrives. 

This is the d11-15 mean from the 6z GEFS. Looks half decent at face value but the elongated area of lower heights is most likely a product of troughs traversing the country with ridging out in front of each one. What we REALLY need to happen is closer spacing in this pattern. That would keep storms from getting organized and amplified and give us a much better shot at overrunning with a weak wave or front end with a cut west. Right now I'm not a fan of the spacing of shortwaves. It's a warm/wet cold/dry pattern for sure. 

 

Last night's eps move quite a step away from the big area of low heights in the GOA. But the flip flopping means that it's awful muddy out in time no sense worrying about anything one way or another. 

[Bob Chill]

Just now, Bob Chill said:

The thing about ensemble troughs that show relatively static isn't really how it works in real time. Everything is always on the move. The burning question is whether we can line something up while things are moving. Right now anything organized is going to cut. Trough axis hasn't been favorable and without a more significant block down stream, anything organized in the northern stream is going to have a much easier time going west of us. I agree that it doesn't mean it can't work out on the front end but right now models are keeping spacing far enough apart that air masses are pretty stale by the time precip arrives. 

This is the d11-15 mean from the 6z GEFS. Looks half decent at face value but the elongated area of lower heights is most likely a product of troughs traversing the country with ridging out in front of each one. What we REALLY need to happen is closer spacing in this pattern. That would keep storms from getting organized and amplified and give us a much better shot at overrunning with a weak wave or front end with a cut west. Right now I'm not a fan of the spacing of shortwaves. It's a warm/wet cold/dry pattern for sure. 

 

Last night's eps moved quite a step away from the big area of low heights in the GOA. But the flip flopping means that it's awful muddy out in time no sense worrying about anything one way or another. 

 

[psuhoffman]

6 minutes ago, Bob Chill said:

The thing about ensemble troughs that show relatively static isn't really how it works in real time. Everything is always on the move. The burning question is whether we can line something up while things are moving. Right now anything organized is going to cut. Trough axis hasn't been favorable and without a more significant block down stream, anything organized in the northern stream is going to have a much easier time going west of us. I agree that it doesn't mean it can't work out on the front end but right now models are keeping spacing far enough apart that air masses are pretty stale by the time precip arrives. 

This is the d11-15 mean from the 6z GEFS. Looks half decent at face value but the elongated area of lower heights is most likely a product of troughs traversing the country with ridging out in front of each one. What we REALLY need to happen is closer spacing in this pattern. That would keep storms from getting organized and amplified and give us a much better shot at overrunning with a weak wave or front end with a cut west. Right now I'm not a fan of the spacing of shortwaves. It's a warm/wet cold/dry pattern for sure. 

 

Last night's eps move quite a step away from the big area of low heights in the GOA. But the flip flopping means that it's awful muddy out in time no sense worrying about anything one way or another. 

Great analysis as usual. Only things I am add are it's important to keep in mind that as we are just entering this new longwave pattern it's possible the models aren't seeing smaller shortwaves imbedded between the more significant ones entering the North American domain.  One opportunity we will have is if any of these can amplify. That would then throw the whole series of events into a better alignment. That's what happened with some of the gfs runs a couple days ago.  One of the weaker waves between troughs amped up before the confluence behind the previous wave was lost. Then it created confluence behind it for the next wave. Domino effect.  Short of that we will struggle of the systems are spaced out 4 days apart. The bigger problem to me is not the trough axis but that the whole pattern from the blocking to the trough under it is displaced just a tad bit north of where I'd like to see it. Get the center of the blocking down into the bearing straight into northern Quebec and push the trough down into the us more and we wouldn't have to worry about spacing as much. Get this same pattern in mid January and it might work better also. It's a servicable pattern that holds potential but it's flawed for sure. 

[Bob Chill]

2 minutes ago, psuhoffman said:

Great analysis as usual. Only things I am add are it's important to keep in mind that as we are just entering this new longwave pattern it's possible the models aren't seeing smaller shortwaves imbedded between the more significant ones entering the North American domain.  One opportunity we will have is if any of these can amplify. That would then throw the whole series of events into a better alignment. That's what happened with some of the gfs runs a couple days ago.  One of the weaker waves between troughs amped up before the confluence behind the previous wave was lost. Then it created confluence behind it for the next wave. Domino effect.  Short of that we will struggle of the systems are spaced out 4 days apart. The bigger problem to me is not the trough axis but that the whole pattern from the blocking to the trough under it is displaced just a tad bit north of where I'd like to see it. Get the center of the blocking down into the bearing straight into northern Quebec and push the trough down into the us more and we wouldn't have to worry about spacing as much. Get this same pattern in mid January and it might work better also. It's a servicable pattern that holds potential but it's flawed for sure. 

 

Totally agree about smaller features. Once we get past thursday or so the possibility for a medium range threat (<5 days) to suddenly appear increases quite a bit. Those types of deals are far better than a getting a couple of good looks on a stronger shortwave d7+ only to watch it morph into a rainstorm. 

The d11-15 mean for the EPS looks better than the GEFS for sure. Much better seam between the higher heights in the SW and eastern trough and fairly cool from the 15th onward (mean high temps in the 30's). It was the coldest run in the LR in the last few days. That type of setup could run something under us or close enough west with better air in place. I'm not pessimistic at all because we're not in a shutout pattern. I despise those. But it also doesn't look like a clean cold storm pattern either. Could still happen with perfect alignment of features but nothing that can be resolved at anything but med-short leads. 

[Stormcatt]

I was reading Cosgrove weekend update.  He sees longer term as warmer with trough to left of EC.  We shall see.  

His forecasts over the last few years haven't been very reliable to say the least .

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[ErinInTheSky]

GFS with snow at 84 hours.

 

 

If it is going to do anything with tomorrow's system, it's going to be very brief. temps are well above freezing when precip moves into the area overnight. 

westminster:

06z 33

12z 31

18z 38

precip moves in after 12z as temps rise. 

 

1 hour ago, mappy said:

If it is going to do anything with tomorrow's system, it's going to be very brief. temps are well above freezing when precip moves into the area overnight. 

westminster:

06z 33

12z 31

18z 38

precip moves in after 12z as temps rise. 

And this output is from.........?

 

 

[BristowWx]

1 hour ago, Stormcatt said:

His forecasts over the last few years haven't been very reliable to say the least .

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Perhaps.  But interesting the uber LR GFS 12z shows just that scenario.  Sure we get cold for a while but the trough sets up west of us and the cold stays there.  Just an op run so not putting too much stock however it shows how extreme cold does make it into the US making it a December to remember in Chicago but never takes hold in the east and kills our snow chances south of 40 as we warm up with every precip maker.  

[Stormcatt]

Perhaps.  But interesting the uber LR GFS 12z shows just that scenario.  Sure we get cold for a while but the trough sets up west of us and the cold stays there.  Just an op run so not putting too much stock however it shows how extreme cold does make it into the US making it a December to remember in Chicago but never takes hold in the east and kills our snow chances south of 40 as we warm up with every precip maker.  

I agree with you. I'm not trashing him. Just seems at least for my area over the last two winters he was wrong alot. But then again so were alot of people

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[WxUSAF]

Let's keep discussion for tomorrow and Thursday in the obs and disco thread.

[Thanatos_I_Am]

FWIW GEFS mean looking a tad bit better from the 6z. About 3.5" in DC and up to 6" North and West of the city.

[psuhoffman]

GEFS has a better look in the day 8-12 ish area then gets weird in the super long range.  It did lose the idea of the alaska vortex though, thats good, rather not have to fight that all winter, but it still manages to bottle most of the cold up in western canada and develop ridging under it even with ridging over the pole.  Kind of unusual.  Typically when the PV is displaced off the pole the cold tends to be more expansive and not tightly wound up like that.  The blocking is a bit far to the north for our needs though.  But we are taking super crazy far out there anyways and it is shifting around with major features so.....  In the more realistic range it did improve and the mean snowfall responded with close to 6" touching the NW ti of DC and around 8" for my area.  Quite a few big hits in the ensemble also and very few total shutouts.  good look overall just scanning over them. 

[yoda]

44 minutes ago, Thanatos_I_Am said:

FWIW GEFS mean looking a tad bit better from the 6z. About 3.5" in DC and up to 6" North and West of the city.

For what time period is this?

[WinterWxLuvr]

42 minutes ago, Thanatos_I_Am said:

FWIW GEFS mean looking a tad bit better from the 6z. About 3.5" in DC and up to 6" North and West of the city.

I'm not sure how an ensemble mean snowfall is useful.

Let's say you had a two member mean.  One could have a 100" storm.  One could have zero.  50" for the mean would sound pretty good.

[Bob Chill]

1 minute ago, WinterWxLuvr said:

I'm not sure how an ensemble mean snowfall is useful.

Let's say you had a two member mean.  One could have a 100" storm.  One could have zero.  50" for the mean would sound pretty good.

Agreed. Especially with the GEFS. EPS is better as a smoothed mean because it has 50+ members. Looks good though:

 

 

 

But digging in deeper and seeing how a lot of those member runs get there is not as rosy. Lots of flawed stuff (west track/changeover etc). That's to be expected given the pattern but in this case I think a lot of these panels are way too forgiving considering the types of storms they represent. 

[mitchnick]

3 minutes ago, Bob Chill said:

Agreed. Especially with the GEFS. EPS is better as a smoothed mean because it has 50+ members. Looks good though:

 

 

 

But digging in deeper and seeing how a lot of those member runs get there is not as rosy. Lots of flawed stuff (west track/changeover etc). That's to be expected given the pattern but in this case I think a lot of these panels are way too forgiving considering the types of storms they represent. 

#2 PLEEEEZZZZ.....

I am not worthy   

[WinterWxLuvr]

Just now, Bob Chill said:

Agreed. Especially with the GEFS. EPS is better as a smoothed mean because it has 50+ members. Looks good though:

 

 

 

But digging in deeper and seeing how a lot of those member runs get there is not as rosy. Lots of flawed stuff (west track/changeover etc). That's to be expected given the pattern but in this case I think a lot of these panels are way too forgiving considering the types of storms they represent. 

 

Exactly. 

I like to look at the ensembles when I can look at a small time period.  IOW, I would like to look at Monday 12z to 18z to see whether there was any consensus among the members.  BTW, does WB have that feature or are we limited to seeing a cumulative map? 

[psuhoffman]

32 minutes ago, WinterWxLuvr said:

I'm not sure how an ensemble mean snowfall is useful.

Let's say you had a two member mean.  One could have a 100" storm.  One could have zero.  50" for the mean would sound pretty good.

Like any other tool they are only useful if you know how to use them. Can you simply take the mean and think it's a forecast no. But as one more data point they are worth a glance to get an idea of trends. Plus if you actually look at how the mean is derived they give clues. Only a few show a total shutout. A few big hits bit they aren't the majority either. Lots of flawed storms but ones that have some frozen in them. That's a clue to what the gefs thinks the pattern is going to look like. Again they aren't meant to be a forecast just a tool to help get to a forecast. 

[showmethesnow]

4 hours ago, WinterWxLuvr said:

You are forgetting that cold air pushes from the west and is also hard to dislodge from the east.  If you want winter weather, you have to have precip.

Yes you flirt with cutters, but at least you have a chance.  Trough on top of us, no chance.

The problem is the Left Cosgrove is referring to is probably left as in the center of the country/plains. Without decent blocking up top or even a cut off, in most cases you will be talking a cutter where you are praying you can get a little front end loving or a little tail end mood flakes.

[psuhoffman]

28 minutes ago, WinterWxLuvr said:

 

Exactly. 

I like to look at the ensembles when I can look at a small time period.  IOW, I would like to look at Monday 12z to 18z to see whether there was any consensus among the members.  BTW, does WB have that feature or are we limited to seeing a cumulative map? 

No but it's easy to figure out by looking at the totals at the start and end of the period you want to see. 

[Eskimo Joe]

29 minutes ago, mitchnick said:

#2 PLEEEEZZZZ.....

I am not worthy   

E12, 14 or 17 please.  The rest are meh.  

[showmethesnow]

1 hour ago, Thanatos_I_Am said:

FWIW GEFS mean looking a tad bit better from the 6z. About 3.5" in DC and up to 6" North and West of the city.

Where are you grabbing the GEFS snowfall mean from? Have weatherbell and to the best of my knowledge that isnt available there.

[PaEasternWX]

9 minutes ago, showmethesnow said:

Where are you grabbing the GEFS snowfall mean from? Have weatherbell and to the best of my knowledge that isnt available there.

It is

 

[showmethesnow]

4 minutes ago, PaEasternWX said:

It is

 

Have never come across the GEFS snowfall mean on weatherbell. Where do they hide it?

[Ginx snewx]

4 minutes ago, showmethesnow said:

Have never come across the GEFS snowfall mean on weatherbell. Where do they hide it?

Ens mean is the last panel in the http://models.weatherbell.com/gefs/gefs_precipitation.php

[showmethesnow]

2 minutes ago, Ginx snewx said:

Ens mean is the last panel in the http://models.weatherbell.com/gefs/gefs_precipitation.php

Can't believe I have spent 3 years searching for that and all the time it was right in front of my face. Thought that was just another member. Thanks.

[Ginx snewx]

24 minutes ago, showmethesnow said:

Can't believe I have spent 3 years searching for that and all the time it was right in front of my face. Thought that was just another member. Thanks.

No Problem

[Bob Chill]

Ginx = WxLinkoPedia