January/February Medium/Long Range Disco

[Fozz]

5 minutes ago, anotherman said:

True, no power issues, but boy was it impactful.  I lived near Owings Mills at the time.

Yep, it was probably the most impactful winter storm between PDII and 09-10. Much more than even the MECS a year earlier that vanished in a few days.

I wouldn't mind a repeat of VD 07, but I absolutely dread the thought of a big ice storm.

[jayyy]

6 minutes ago, Fozz said:

Damn.... that is so close to being something really good for us.

Still plenty of time. Only thing holding back my excitement for Baltimore and northern part of the forum is the trend this year has been to go north, not south. But.. hell, I’ll take one reversal for this storm!

[Fozz]

4 minutes ago, frd said:

The NAO is very stubborn.

 I guess the NAO is awaiting Feb to dive negative. Well, I am waiting. 

To match some long range looks up top and near Greenland you expect to see it trend South.

Maybe I am missing something. 

 

Seems to be in line with the general expectation of a nice block at the end of the month. Let's hope this doesn't get delayed.

[jayyy]

We about to get long range NAM’d?! 

[Scarlet Pimpernel]

25 minutes ago, mappy said:

i saw your tweet about that. i wasn't in the Baltimore region for that storm but recall it being messy. 

It was indeed a big mess over the entire area.  I think areas farther west in MD/VA/WV got decent snows out of it too.  It was very cold leading into it, and despite the low center going well enough to our west (as I recall?), we never changed over to rain even in the DC area.  We got a bit of snow, then all sleet...about 3-4" worth.  Areas east/southeast of DC (Annapolis, etc.) probably had it worse because they ended up with more freezing rain rather than sleet.  The whole thing then turned into a block of ice for the next couple of weeks as it remained quite cold for the rest of that month.

[PhineasC]

38 minutes ago, mappy said:

yeah, I agree with that. I think, as things stand now, I could pick up a few inches before the flip to rain. but i never expect the flip back to snow to ever work out well. but, as i said, its a pretty strong front pushing through so its possible. 

I agree. The infamous back-end snows often disappoint, but I can recall some cases where it surprised everyone. The models will not be able to get it right until very close in. Zero chance the GFS and Euro have it figured out now. They are still moving the major pieces hundreds of miles every six hours.

[PhineasC]

The NAM blows, but wasn't it first to sniff out the last storm being much more north and wetter than the globals?

NAM does well in a pattern where everything is wound up and wet.

[MD Snow]

1 minute ago, PhineasC said:

I agree. The infamous back-end snows often disappoint, but I can recall some cases where it surprised everyone. The models will not be able to get it right until very close in. Zero chance the GFS and Euro have it figured out now. They are still moving the major pieces hundreds of miles every six hours.

At this point, I think we have an equal chance of a front end thump to a back end changover. 

[Scarlet Pimpernel]

Just now, PhineasC said:

I agree. The infamous back-end snows often disappoint, but I can recall some cases where it surprised everyone. The models will not be able to get it right until very close in. Zero chance the GFS and Euro have it figured out now. They are still moving the major pieces hundreds of miles every six hours.

Yes, those are generally not worth hoping for, but they do happen upon occasion (not saying it will here, though would be nice of course!).  What we'd really need (require?) for that is a trailing piece of energy along the front after it passes through and we're in the cold air again.  And hope the front doesn't move so fast that any secondary wave is pushed too far offshore to affect us.

[MD Snow]

Just now, PhineasC said:

The NAM blows, but wasn't it first to sniff out the last storm being much more north and wetter than the globals?

NAM does well in a pattern where everything is wound up and wet.

It was. 

[mappy]

4 minutes ago, PhineasC said:

I agree. The infamous back-end snows often disappoint, but I can recall some cases where it surprised everyone. The models will not be able to get it right until very close in. Zero chance the GFS and Euro have it figured out now. They are still moving the major pieces hundreds of miles every six hours.

yup, this. Until tomorrow's system comes through and lays the boundary, no way will the models nail down the solution for saturday/sunday right now. 

[jayyy]

1 minute ago, MD Snow said:

At this point, I think we have an equal chance of a front end thump to a back end changover. 

False. Back end changeovers rarely happen. Front end WAA thumps before the CAD erodes happen here frequently.  Christmas 01 I believe is like the only major back end thump I can think of and I was in New York for it. Driving rain to 13” of snow on the back end in 6 hours time. A rarity indeed. 

[Ji]

24 minutes ago, frd said:

The NAO is very stubborn.

 I guess the NAO is awaiting Feb to dive negative. Well, I am waiting. 

To match some long range looks up top and near Greenland you expect to see it trend South.

Maybe I am missing something. 

 

 

 

here you go. happy groundhog day

 

[Inthepines]

We had a few between 2013 and 2015

4 minutes ago, jayyy said:

False. Back end changeovers rarely happen. Front end WAA thumps before the CAD erodes happen here frequently.  Christmas 01 I believe is like the only major back end thump I can think of and I was in New York for it. Driving rain to 13” of snow on the back end in 6 hours time. A rarity indeed. 

 

[psuhoffman]

9 minutes ago, Ji said:

here you go. happy groundhog day

 

Ralph loves both op runs of the 6z GFS.  Neither flips the NAO, the PV rotates up into Greenland and just sits there...pieces break off at times and drop but the AO/NAO remains strongly positive.  Luckily this is not the most likely progression.  However, there is a minority camp within the GEFS and EPS that agrees with that and it is why the heights up top are not increasing in the means as we get closer...that is not because it is a "weak" block but because about 1/3 of the members don't agree with the blocking at all and after a brief cold blast go back to warm pattern.  I am aware of that possibility but right now its a minority showing that.  The majority still agrees with the progression we have been expecting.  But it is something to keep an eye on in the next few runs.  IF things are going to fall apart I expect we will see it happen in the next day or two as the blocking should be coming into the magic 10 day range where it becomes more reliably modeled.  We do not want to see it get delayed or pushed back...that would be a sign of trouble.  

[stormtracker]

1 hour ago, PhineasC said:

A storm giving the northern tier good snow while semi-screwing the southern gang would balance the karma of things.

We’ll remember this

[psuhoffman]

back end changeovers only work if there is a trailing wave along the boundary.  If there is a wave with enough circulation to back the flow across the thermal boundary then we can get snow on the backside of a system where the first wave along the front brought rain.  But without a trailing wave, once the winds flip to a westerly trajectory which brings in the cold...we are done because that is a downsloping wind for us and so it will dry out quickly.  We need a second wave to develop that backs the flow across the boundary and creates moisture transport into the cold.  Without that the precip will always leave as the cold arrives.

[MD Snow]

15 minutes ago, jayyy said:

False. Back end changeovers rarely happen. Front end WAA thumps before the CAD erodes happen here frequently.  Christmas 01 I believe is like the only major back end thump I can think of and I was in New York for it. Driving rain to 13” of snow on the back end in 6 hours time. A rarity indeed. 

Cool bro. I honestly don’t think we have much of a chance of either. NAM is already showing more phasing of streams at 12z. However, the strong arctic front would at least give some credence to a back end changeover. By thump I mean changeover because like you say we rarely ever do back end thumps. 

[psuhoffman]

1 minute ago, stormtracker said:

We’ll remember 

There is a way for my area to get screwed again...if the initial WAA thump goes north and then a secondary wave forms and goes southeast...we could be left in a gap where PA north and DC east gets more snow.  Not saying but just saying.  

[notvirga!]

Vd 07 remains one of my favorite storms. I was in Winchester at the time and I think we were expecting upwards of a foot of snow. Well, had it been all snow it would have been a two footer because it was about 2.5 inches of precip. I've never seen a sleet storm like that in my life. Heavy sleet pounded the roof and windows all night long and by morning there was about 7 inches of sleet. As others have noted, it briefly warmed up and then froze solid resulting frozen blocks of ice which plows couldn't touch. You needed a jack hammer to break them up. At the parking lot of my apartment complex you had to drive up onto the blocks of ice to park. The ice lasted for 3-4 weeks at least. 

[stormtracker]

3 minutes ago, psuhoffman said:

There is a way for my area to get screwed again...if the initial WAA thump goes north and then a secondary wave forms and goes southeast...we could be left in a gap where PA north and DC east gets more snow.  Not saying but just saying.  

You and I both know that’s not going to happen. Anyway, your region looks better and if I lived where you did, I’d be excited about the trends.  But I’m resigned to this being rain here.  For us here, I think people should temper the excitement.  I don’t expect models to make the drastic change we would need.  There’s only but so much that it can swing.  I hope I’m wrong. 

[psuhoffman]

1 hour ago, leesburg 04 said:

In the back of my mind I'm beginning to think Bob is doing the reverse psychology thing

Maybe but what he said about the H5 pattern was right.  But anytime you have arctic air displaced south to our latitude its never a shutout pattern and flukes can happen.  Most of our snowstorms are not perfect setups.  Those don't come around very often.  Many come from flawed bootleg setups and we just get lucky.  This setup is interesting because it has us rooting for the opposite trends than if we had nao blocking and a 50/50 low.  Then we would be rooting for phasing and an amped up consolidated monster to attack the cold that is locked in.  In this setup, with a transient high and WAR we want the STJ system to remain unphased and traverse across under the NS for as long as possible.  Our only way to snow is either from a weak un phased system cutting under the NS OR if multiple weaker waves eject along the front and a trailing wave clips us after the boundary crosses.  Both of those are the opposite of what we would want if we had the ideal setup.  But sometimes you just luck your way into something and when we have a -epo and cold around it allows us the chance for that.  The pac crap pattern we were in before was a shutout pattern because no matter the storm track cold air was 500 miles away.  

[Ralph Wiggum]

7 minutes ago, psuhoffman said:

Ralph loves both op runs of the 6z GFS.  Neither flips the NAO, the PV rotates up into Greenland and just sits there...pieces break off at times and drop but the AO/NAO remains strongly positive.  Luckily this is not the most likely progression.  However, there is a minority camp within the GEFS and EPS that agrees with that and it is why the heights up top are not increasing in the means as we get closer...that is not because it is a "weak" block but because about 1/3 of the members don't agree with the blocking at all and after a brief cold blast go back to warm pattern.  I am aware of that possibility but right now its a minority showing that.  The majority still agrees with the progression we have been expecting.  But it is something to keep an eye on in the next few runs.  IF things are going to fall apart I expect we will see it happen in the next day or two as the blocking should be coming into the magic 10 day range where it becomes more reliably modeled.  We do not want to see it get delayed or pushed back...that would be a sign of trouble.  

Instigate much? I've backed off the LR stuff for now it has been unreliable in general and you know this. Didnt even look at the ops at range tbh until this was posted. But no I dont like this look at all. I sense some concerns and cracks in your armor starting to surface regarding the epic pattern change. I'm not worried about it.

[MD Snow]

4 minutes ago, stormtracker said:

You and I both know that’s not going to happen. Anyway, your region looks better and if I lived where you did, I’d be excited about the trends.  But I’m resigned to this being rain here.  For us here, I think people should temper the excitement.  I don’t expect models to make the drastic change we would need.  There’s only but so much that it can swing.  I hope I’m wrong. 

Was reading in the NE forum and they were saying that the region the southern shortwave is going through is an area that lacks good sampling. That may be one of the reasons for a weaker less phased system. The trends could continue but it could also go back to being a more westerly wound up system if the southern system is being sampled to weak right now. 

 

Looks like the 12z NAM is coming back to reality. 

[87storms]

cmc hints at what's going wrong with this weekend system as it's showing phasing way north with that ns energy.  not sure if that's how it'll work out, but we need this system to stay separated and/or have it lagging behind that reinforced blocking.  i may have some of these details confuzzled, but i think we want a slower overall ss or a trailing wave to start appearing so that we actually have precip to work with when temps crash.

[mappy]

Just now, MD Snow said:

Was reading in the NE forum and they were saying that the region the southern shortwave is going through is an area that lacks good sampling. That may be one of the reasons for a weaker less phased system. The trends could continue but it could also go back to being a more westerly wound up system if the southern system is being sampled to weak right now. 

weenie rule #648465: lack of sampling

[psuhoffman]

2 minutes ago, stormtracker said:

You and I both know that’s not going to happen. Anyway, your region looks better and if I lived where you did, I’d be excited about the trends.  But I’m resigned to this being rain here.  For us here, I think people should temper the excitement.  I don’t expect models to make the drastic change we would need.  There’s only but so much that it can swing.  I hope I’m wrong. 

I am not that excited for up here either.  This kind of reminds me of a couple waves in 2015 BEFORE it got better around here, during a similar -epo +nao pattern, where they started way north then trended south and got us kind of interested in the medium range, only to make the typical north adjustment the last 48 hours and disappoint.   Once in a while you get a south adjustment right to the end...but usually that is when there is a vort diving down on top like the early March 2014 storm.  Maybe if the trend to separate the streams continues and the NS ends up suppressing instead of phasing that might happen here.  The later phase has trended things south but we would need a complete non phase I think to get it under us.  Either way if we are going to see that happen it should be soon because once the wave is out into the plains the typical adjustment the last 24-36 hours is almost always more amped and that is no good if we are living dangerously on the southern edge, even up here.  

[MD Snow]

4 minutes ago, mappy said:

weenie rule #648465: lack of sampling

But the lack of sampling this time would not be in our favor.  So not a weenie rule. And I’m pretty sure it was a met making the post. His point was that even though it looks there is s positive trend right now it could easily go right back to the way it looked yesterday. 

[DDweatherman]

2 minutes ago, psuhoffman said:

I am not that excited for up here either.  This kind of reminds me of a couple waves in 2015 BEFORE it got better around here, during a similar -epo +nao pattern, where they started way north then trended south and got us kind of interested in the medium range, only to make the typical north adjustment the last 48 hours and disappoint.   Once in a while you get a south adjustment right to the end...but usually that is when there is a vort diving down on top like the early March 2014 storm.  Maybe if the trend to separate the streams continues and the NS ends up suppressing instead of phasing that might happen here.  The later phase has trended things south but we would need a complete non phase I think to get it under us.  Either way if we are going to see that happen it should be soon because once the wave is out into the plains the typical adjustment the last 24-36 hours is almost always more amped and that is no good if we are living dangerously on the southern edge, even up here.  

Well we basically just lost the NAM. Its still not as north or amped as the other models, but its not where we liked it de-amped compared to the other models. Low is in Kentucky versus the 6z time where it was in Louisiana. 

Of course the middle ground crushes you and I up here on the front end. 

[PivotPoint]

12z nam says it probably ain’t happening. Sped up and more interaction with NS. That was a quick glimmer. Was hoping to get to happy hour namming