January Medium/Long Range Discussion

[CAPE]

4 minutes ago, Ralph Wiggum said:

I somewhat agree with this. Whenever the transient neutral/negative NAO briefly appears, the SE Ridge vanishes and cold air plows to the Gulf Coast and tries to suppress the storm track. When the SE Ridge pops to help systems come North, the N Atl ridge is nowhere to be found and systems come N but cut West. We are having a real challenge thus far in getting the Atl to work for us. I guess the old saying goes, get the cold first then worry about storms. Pac should work for us (-WPO/-EPO) to provide the cold in the LR anyway. Fingers crossed.

Meh. There are always "risks". It does not look like we are going to shake the western trough anytime soon. With a -PNA we likely need help with NA blocking, even if its short lived. This is far from perfect because we still have to time something, but it is what it is. At least we have a shot with what is currently being advertised on the guidance in 10 days or so.

[mattie g]

8 hours ago, nw baltimore wx said:

Though it's only been a month, this is the first time that I can recall this winter that a modeled "event" has trended in the right direction for us. I'm talking about overnight Sunday into Monday, and although it doesn't look to be a snowy, it has potential to impact the morning rush on Monday morning.

Luckily Monday is a holiday.

[Ralph Wiggum]

At least we have a shot with what is currently being advertised on the guidance in 10 days or so.

No doubt! Threats are fun to track and nothing is etched in stone.

[mdsnowlover]

43 minutes ago, psuhoffman said:

Cold but not what we want if you want snow. We're better off with the cold coming across further north and the high being across the north allowing a system to ride along under it. Not good is an arctic shot straight south squashing anything then a system going up west as the cold exits. 

I was there last November, I was lamenting for them, that's awful cold for them.

[nw baltimore wx]

13 minutes ago, mattie g said:

Luckily Monday is a holiday.

For most, but not all (me). Kind of why I'm rooting so hard for it!

[WinterWxLuvr]

I suppose one has to put faith in ensembles which look pretty good, but I have to admit that each morning after looking at everything I feel like one of those cats chasing a laser light.

[poolz1]

18 minutes ago, WinterWxLuvr said:

I suppose one has to put faith in ensembles which look pretty good, but I have to admit that each morning after looking at everything I feel like one of those cats chasing a laser light.

lol...perfect analogy.  Ens are good I guess but I was hoping that the eps were onto something yesterday at 12z....they reverted back to the gefs look in the LR.  Not a disaster at all, I was just hoping we would see that look grow and show up on the gefs.  

I know the eps beats the gefs and that can't be disputed but imo when the gefs are relentless with a particular look in the LR, they usually hold that general look.  

[frd]

Very little confidence in any real threats in my opinion, because this morning the forecasted sharp drop in the AO is not nearly as impressive on the ensembles.

Also, the overnight EPS shortened the cold period, and it appears the SE ridge makes a come back.  Not sold on anything yet, except the possibility of a very short window

of oppurtunity.   Looking back not only has the NAO been forecasted to go negative and has not followed forecasts,  but so has the AO to a degree. 

[CAPE]

9 minutes ago, frd said:

Very little confidence in any real threats in my opinion, because this morning the forecasted sharp drop in the AO is not nearly as impressive on the ensembles.

Also, the overnight EPS shortened the cold period, and it appears the SE ridge makes a come back.  Not sold on anything yet, except the possibility of a very short window

of oppurtunity.   Looking back not only has the NAO been forecasted to go negative and has not followed forecasts,  but so has the AO to a degree. 

Agreed 0z is not as impressive as the 12z EPS, especially towards the end of the run. Loses the ridging over GL, the AK ridge is not poking as far pole-ward and it pulls back towards the Aleutians, leading to a more pronounced western trough. All that combined is enough to establish ridging along the east coast. For now the period centered on day 10 is what we need to be focusing on.

[yoda]

3 hours ago, psuhoffman said:

Careful what you wish for. EPS was a good run overall but there's a lot of misses to the south. I count 18 for D.C. And 23 for me. A couple squash the system totally.  Unlike gefs almost no signal for a west track.  The other half are nice hits. A blend of the gefs and eps (typically a good way to go) actually is a very good look for us. 

It's probably better for now that the system is squashed to our south... it will come north eventually  

I agree that a blend looks very nice for us

ETA: 06z GEFS does have some nice hits in the LR amongst it's members

[psuhoffman]

Our window is day 8-12.  Most of the posts are focused after that for some reason. Things will relax. as long as we keep ridging around AK and the AO isn't killing us we likely aren't heading back to a long term endless ridge like we have been. Especially that time of year the cold will push and while it may not be ideal we could get chances. If the nao ever decides to actually go negative for a meaningful period it could be a good pattern. Day 15+ is muddy but I do not think we're going into a long term warm up. If you look at individual runs of the ops and even ensemble they don't show a long sustained ridge. They do support a relax and something cutting around day 14-15.  But most then show cold pushing right away after. The ens mean washes that out and you only see the ridge because of timing differences between members.

As for our threat window day 8-12.   Not 100% sold that last wave along the front Jan 4-5th bombs up west.  That's really screwing things up though. Originally that was actually our first of two threats in the window. But the storm ahead of it is slower and bombs up west stalling the cold progress. Then the next system rides up west also along the front. The bigger problem is if it bombs out and squashes the day 10-12 system. A lot of runs do that. The cutter day 13-15 is not and never was our threat. The one change is on the Atlantic side. The higher heights are centered a bit east of where they were shown yesterday. That can be trouble as it allows the trough  to stall and that Jan 4 system to cut. We still get a good look after but it's possible messed up if the flow is too suppressive behind that storm.  All that said it's still a good look. Maybe I would downgrade from an 8 to a 7 today but it's not jump time. And after is muddy not awful looking. 

[stormtracker]

1 hour ago, WinterWxLuvr said:

I suppose one has to put faith in ensembles which look pretty good, but I have to admit that each morning after looking at everything I feel like one of those cats chasing a laser light.

I can't understand the enthusiasm and joy here lately...I'm not going to put a damper on it...but I feel zero optimism.  **** keeps changing every 4 days....things look great...then bad..then great..and just as easily bad.  "It's just 10 days away" is making a comeback this year.  

[CAPE]

6 minutes ago, stormtracker said:

I can't understand the enthusiasm and joy here lately...I'm not going to put a damper on it...but I feel zero optimism.  **** keeps changing every 4 days....things look great...then bad..then great..and just as easily bad.  "It's just 10 days away" is making a comeback this year.  

Its a crappy pattern overall. We keep getting sucked in every time we see a modeled -NAO. Call it voodoo, urban myth, chasing unicorns, whatever. It doesn't ever seem to verify tho. All that said, the pieces do shift around from time to time, and we can get more favorable looks, even if it is transient. Lets hope this day 8-12 window is legit, and we can take advantage. Its all we got right now.

[psuhoffman]

11 minutes ago, stormtracker said:

I can't understand the enthusiasm and joy here lately...I'm not going to put a damper on it...but I feel zero optimism.  **** keeps changing every 4 days....things look great...then bad..then great..and just as easily bad.  "It's just 10 days away" is making a comeback this year.  

For me the optimism was simply getting out of the stable +wpo, epo, ao, nao pattern. That's a no hope look. We're never going to get snow in that. Not even a fluke. Signs of a pattern shift started showing up a week ago. And moving closer in time. The pattern actually is changing. In general from a flat out awful one towards a more typical (in normal years) meh pattern. It may not rock consistently but we could get windows of opportunity. One looks to be day 8-12 and it's been consistent and locked in time. 

I think this is about expectations. I'm pretty resigned that this is likely a tough year. Going to be a struggle to get snow. But if we're trying to fight and eek our way to at least a respectable total, say 10-15" in the cities, this look is better then what we've had. I'm not excited thinking we will get a lot of snow I'm excited at least we might get some. Some kind of just assume or ignore the chances we get one of our total non winters but 10 days ago when the pattern was just atrocious and 1973, 1991, 2002, 2008, and 2012 were all showing up in the analogs I was wondering if we weren't staring a total wasted year in the face. We may still be honestly but I have more hope now then a week ago. 

[psuhoffman]

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

Its a crappy pattern overall. We keep getting sucked in every time we see a modeled -NAO. Call it voodoo, urban myth, chasing unicorns, whatever. It doesn't ever seem to verify tho. All that said, the pieces do shift around from time to time, and we can get more favorable looks, even if it is transient. Lets hope this day 8-12 window is legit, and we can take advantage. Its all we got right now.

The nao is going negative. But it's not timed up well. It goes negative before the AK ridge does its work in forcing the trough axis east a bit. So when the nao is negative there is still ridging in the east. It does help cause this blizzard for interior New England though. Not every nao helps us. After that the PAC cooperates for a while but we lose the nao. After that who knows. But the nao hasn't been wall to wall positive it's just not timing up well for our purposes so far. 

[psuhoffman]

Since negativity seems to be the rule of the day I'll share two things that I keep seeing that does bother me. The first is the strength persistence of the eastern ridge even when the pattern as a whole isn't that bad. The ridge in the east just seems to want to be even stronger then I would expect given the overall pattern at times. It's amazing that the first look below which isn't that bad (-nao) somehow morphs into that ridge 48 hours later and 3 cutters back to back. Yea the nao is east based and the AK ridge is slightly west of ideal but we're in trouble if the only way to beat down the ridge is with an absolutely perfect setup in every detail. 

[CAPE]

8 minutes ago, psuhoffman said:

The nao is going negative. But it's not timed up well. It goes negative before the AK ridge does its work in forcing the trough axis east a bit. So when the nao is negative there is still ridging in the east. It does help cause this blizzard for interior New England though. Not every nao helps us. After that the PAC cooperates for a while but we lose the nao. After that who knows. But the nao hasn't been wall to wall positive it's just not timing up well for our purposes so far. 

I acknowledge there has been some transient NA blocking. A legit -NAO (sustained for more than a few days) is what we need tho, and would significantly improve our chances in this pattern. Otherwise it will take some changes out west, or its the usual pure luck with timing something.

[Bob Chill]

So far this year all events have trended north as leads shorten. I'm not worried about suppression at all until it's inside of 5 days and showing it. And even then if we are on the northern fringe it will likely shift in our favor. OTOH- if we are on the southern edge of something @ d5 then I won't feel good at all. 

Overrunning along boundaries are typically in the 2-4/3-5 range. Without synoptic support it's hard to get a big precip maker. But this is probably what I'm rooting for the most. Until seasonal trends change, a strong low is probably going to have a lot of problems in our area. Not that what I prefer means a damn thing but until we shake the goose egg I'm going to root for easy and clean even if the event is smallish. 

There's going to be a lot of hand wringing this week over every run but it seems kinda silly to talk about discreet events. We're at least 3-4 shortwaves away from having one to really talk about. As long as the general broad trough idea hangs on with HP to the north I'll be happy with every run regardless of whether it looks better or worse for a specific threat. 

[psuhoffman]

The other thing and it's related to the ridging is his often I've seen a model run with a pretty darn good surface setup, low in the gulf, wall of high pressure above it, and the whole wave just lifts north west of us anyways. I know it's just models but they are based of realistic predictions on the pattern. It's a bit troubling to me when I keep seeing looks where a wave to our south has a baroclinoc path of least resistance to our southeast and instead just lifts due north up to the lakes.  This is the latest example. How the heck does that first look end up a rainstorm 24 hours later. Or ice to rain anyways. Now  I actually think given that setup we would do ok and the model is wrong but it bothers me that even in that setup we have trouble. So there are things bothering me about the pattern this year but it's still early so my hope is this changes or we overcome them. 

[psuhoffman]

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

I acknowledge there has been some transient NA blocking. A legit -NAO (sustained for more than a few days) is what we need tho, and would significantly improve our chances in this pattern. Otherwise it will take some changes out west, or its the usual pure luck with timing something.

Your right but I guess the point i was making is we are in trouble if the only way we can get snow is if we get a stable west based negative nao. Do you know how rare that is?  I'm also not sold yet the models are accurate in their depiction of the strength of the eastern ridging given some other factors are pretty favorable.  I wouldn't be shocked if it's more muted. 

[Bob Chill]

There is a good side to transient blocks. Many of our events happen as a -nao (bootleg or classic) is on the retreat. I have a bunch of NAO bar graphs I made from previous events and the majority came as the NAO was moving towards neutral. I'll try and dig them up and post if I can find them. 

[Thanatos_I_Am]

There is a good side to transient blocks. Many of our events happen as a -nao (bootleg or classic) is on the retreat. I have a bunch of NAO bar graphs I made from previous events and the majority came as the NAO was moving towards neutral. I'll try and dig them up and post if I can find them. 

I think I remember Ian saying that happened before last years storm. The NAO was moving towards neutral (along with the rest of the pattern flipping). The block was also flexing as well.

[WinterWxLuvr]

Always heard models struggle during pattern changes so we probably don't have a lot of reliable guidance beyond about 3 days.

However, for the collective sanity of the board, the 12 day gfs delivers up a soothing elixir of cold powder.

[soadforecaster]

6 minutes ago, Bob Chill said:

There is a good side to transient blocks. Many of our events happen as a -nao (bootleg or classic) is on the retreat. I have a bunch of NAO bar graphs I made from previous events and the majority came as the NAO was moving towards neutral. I'll try and dig them up and post if I can find them. 

all you need to do is look at last year hecs, we tanked the nao and as it went to neutral we got the storm. I feel like a lot of our classic big storms come as the nao is on the rise from negative

[gymengineer]

Just now, WinterWxLuvr said:

Always heard models struggle during pattern changes so we probably don't have a lot of reliable guidance beyond about 3 days.

However, for the collective sanity of the board, the 12 day gfs delivers up a soothing elixir of cold powder.

I was wondering if seeing the 288-hr depiction was going to make people feel better or worse. Worse because "it can't possibly be right since it's never going to snow." 

I've said before- our collective tolerance for a  more common (as in "challenging") winter seems to have gone out the window. 

[psuhoffman]

15 minutes ago, Bob Chill said:

So far this year all events have trended north as leads shorten. I'm not worried about suppression at all until it's inside of 5 days and showing it. And even then if we are on the northern fringe it will likely shift in our favor. OTOH- if we are on the southern edge of something @ d5 then I won't feel good at all. 

Overrunning along boundaries are typically in the 2-4/3-5 range. Without synoptic support it's hard to get a big precip maker. But this is probably what I'm rooting for the most. Until seasonal trends change, a strong low is probably going to have a lot of problems in our area. Not that what I prefer means a damn thing but until we shake the goose egg I'm going to root for easy and clean even if the event is smallish. 

There's going to be a lot of hand wringing this week over every run but it seems kinda silly to talk about discreet events. We're at least 3-4 shortwaves away from having one to really talk about. As long as the general broad trough idea hangs on with HP to the north I'll be happy with every run regardless of whether it looks better or worse for a specific threat. 

Great points. I'm not really worried about suppression yet just was discussing all the possibilities. Your right about the seasonal trend and that should be given weight.  Those things I mentioned above do bug me but more on a seasonal note the day 10 threat still looks solid to me. It's just going to be a struggle this year. Not a year snow comes easy. 

Im also kind of down today because we had a shot at an inch or two of snow up here tomorrow, at least on most of the guidance, and as usual things trended 2-3 degrees warmer so now looks like just rain. I wasn't shocked but disappointed. I don't talk about it because no one cares about 1-2" up here but my 2 year old is dying to use his new sled and keeps asking about snow and I just want 2" so he is happy. To him that would be the same as 2 feet. But I decided to go up to pa tomorrow and let him have a snow day.  I'll try to be back to my more optimistic self. 

[psuhoffman]

12 minutes ago, Bob Chill said:

There is a good side to transient blocks. Many of our events happen as a -nao (bootleg or classic) is on the retreat. I have a bunch of NAO bar graphs I made from previous events and the majority came as the NAO was moving towards neutral. I'll try and dig them up and post if I can find them. 

It just makes sense because a string nao would be suppressive. Best scenario would obviously be when the nao helps lock the cold in then as it relaxes a system is able to push north into the cold. 

[Thanatos_I_Am]

Alright PSU, question. I know this is fantasy land (I'm really just trying to learn here lol) but why would that low just slide off the coast? Why not move north?

[CAPE]

22 minutes ago, psuhoffman said:

Your right but I guess the point i was making is we are in trouble if the only way we can get snow is if we get a stable west based negative nao. Do you know how rare that is?  I'm also not sold yet the models are accurate in their depiction of the strength of the eastern ridging given some other factors are pretty favorable.  I wouldn't be shocked if it's more muted. 

Oh I know its rare, thus why I said its an urban myth and like voodoo when it shows up on the models. Being realistic with the pattern we have (and QBO state etc), we likely wont see it, but a neutral/weakly -NAO from time to time is doable. Without some blocking however, and no change in the mean ridge/trough position out west, then there is the continued tendency for SE/WA ridging and storms cutting west- more of the same.

[Bob Chill]

2 minutes ago, Thanatos_I_Am said:

Alright PSU, question. I know this is fantasy land (I'm really just trying to learn here lol) but why would that low just slide off the coast? Why not move north?
 

You need to look at the upper levels. In this case, the trough has a positive tilt as it passes and confluence (w-e oriented height contours) so the steering flow is more easterly instead of northerly. 

 

Negative tilted troughs will bring low pressure up north quickly and easily. Negative tilt is when the height contours are bent "backwards". I'll see if I can find something that shows it visually.