March 13/14th Storm Thread (Storm Mode)

[psuhoffman]

Navgem is about max potential. 1.6 qpf all snow and even some wrap around northern 1/2 of our region. 

Over the last 24 hours I've heard some chatter about march 2001. There is some upper level similarities but this has a major different in our favor. 2001 had no cold in place. I remember even the big snow runs started as rain and uses dynamic cooling and the low to pull cold down. Temps were expected to crash but even at 850 the boundary was way up to our north. That boundary ended up where the storm decided to set up and bomb. This time the boundary is south. And models have improved a crap ton since then. Just pointing out some differences in this setup. 

[psuhoffman]

4 minutes ago, AlaskaETC said:

Doesn't Euro have the low hugging the coast a bit more, with the low forming right off Hatteras?

Euro hugs to va the turns ene and slides out. 

[SomeguyfromTakomaPark]

Just now, clskinsfan said:

Wow. We snow out here for 27 straight hours on the 18Z GFS. We only pick up an inch the last 9 hours but still would be a really fun event.

Yeah there's definitely something to be said for keeping the clouds and light snow throughout the next day, also I'm pretty happy about below normal temps for the week so the snow doesn't vaporize in 24 hours.

[Bob Chill]

11 minutes ago, RDM said:

What's the normal wheelhouse for the NAVGEM?  Tks

The navgem is a junior varsity model so it's really only good for general support to the main globals. It has a progressive bias and is usually the furthest east and fastest moving with coastals. You could ignore it completely, stick with the euro, ukie, gfs, cmc and the ensembles and have all the data you need to make a forecast. 

[nj2va]

6 minutes ago, AlaskaETC said:

Doesn't Euro have the low hugging the coast a bit more, with the low forming right off Hatteras?

I think it actually looks pretty similar to the Euro to my noobie eye. 

[AlaskaETC]

1 minute ago, psuhoffman said:

Euro hugs to va the turns ene and slides out. 

Yup. The NAVGEM backs off a little more and is more of a classic track if I'm not mistaken.

[cae]

34 minutes ago, psuhoffman said:

I think they looked at the individual members and saw that instead of 5 bad there are 7 or something like that and that's all their seeing. I think having the gfs on the west edge of guidance with the euro east is a good spot to be. Although that's kind of opposite they normal biases. 

It looks like the UKMET and GFS are now very similar on the west edge, and the CMC is on the east edge.  The Euro is in between, but closer to the UKMET / GFS.  Given that setup less than 4 days out, I don't expect the Euro to move much from where it currently is.  It's a good position for us to be in.

[clskinsfan]

3 minutes ago, DCTeacherman said:

Yeah there's definitely something to be said for keeping the clouds and light snow throughout the next day, also I'm pretty happy about below normal temps for the week so the snow doesn't vaporize in 24 hours.

Yes sir. And it looks like there is another legit chance later in the week as well. I agree about keeping the negative departures in place. That is actually really rare in March. I wonder how much of that is because of the snow cover?

[Amped]

13 minutes ago, Ian said:

I've been bothered by the GFS mid levels for a while now but the 18z looked pretty good. It's still a little wonky compared to our truly most classic of setups but it's also disjointed from the actual vort of interest to the lumbering 500 low that pushes by after. Then again who really cares what the GFS says if we have the Euro. 

GFS and Euro are both disjointed with the 850mb low.    Euro just gives some of us a bigger paste bomb with the coastal.   Either way the northern low is going to limit the duration of the event for us. This ain't last years blizzard.

 

 

 

 

[psuhoffman]

4 minutes ago, Bob Chill said:

The navgem is a junior varsity model so it's really only good for general support to the main globals. It has a progressive bias and is usually the furthest east and fastest moving with coastals. You could ignore it completely, stick with the euro, ukie, gfs, cmc and the ensembles and have all the data you need to make a forecast. 

Hopefully everyone knows that but it's important you point it out. I just thought it was something pretty to look at. 

[gymengineer]

18 minutes ago, Ian said:

It's in this thread if you click into it (I guess click the time stamp.. can't figure out how to just link it).. Marciano. I trust his judgment -- saw plenty of other refs when I Googled it. I think of it as a Miller A but I do remember some talk of it being a hybrid way back when. Can sort of see that but it did take a fairly classic track across the northern Gulf and then up the coast.  

(this was yesterday morning.. it has evolved a bit since then into more of this hybrid thingy, or I finally decided to stop believing in it since)

Interesting. Maybe only to me, lol, since I dredged up that discussion this week too. I noticed Halverson writing for you guys described last January's blizzard as following "the evolution of a classic Miller-B." So I guess there are people who just look at whether a significant inland primary redevelops off the coast. 

[Ian]

2 minutes ago, gymengineer said:

Interesting. Maybe only to me, lol, since I dredged up that discussion this week too. I noticed Halverson writing for you guys described last January's blizzard as following "the evolution of a classic Miller-B." So I guess there are people who just look at whether a significant primary pushes inland and redevelops off the coast. 

Hmm, must have missed that one. I'd have to look back at 500mb evolution but that seems like a Miller A as well. Either that or there are very few Miller As. I think Dec 2009 is widely accepted as one... although it wasn't that different than Feb 5-6. So, I dunno. I think it may be that hybrids and such are the predominant type... the Miller classification is pretty old. 

[EastCoast NPZ]

11 minutes ago, DCTeacherman said:

Yeah there's definitely something to be said for keeping the clouds and light snow throughout the next day, also I'm pretty happy about below normal temps for the week so the snow doesn't vaporize in 24 hours.

That would be ideal; else it will be rapid melting.  There is no temperature cold enough in March to prevent meltage on a sunny day.

[psuhoffman]

6 minutes ago, cae said:

It looks like the UKMET and GFS are now very similar on the west edge, and the CMC is on the east edge.  The Euro is in between, but closer to the UKMET / GFS.  Given that setup less than 4 days out, I don't expect the Euro to move much from where it currently is.  It's a good position for us to be in.

I don't think the euro will shift much. One thing I do think is the euro is turning the system east too fast. A compromise between the gfs that blasts it north all the way unto New England and the euro that turns east off va beach is best. These systems often fair a bit more latitude then the euro even has at the last minute. But that wouldn't hurt you. It's west that hurts and the gfs hugging or just inland track is likely overdone. I'd go with a euro track just inside hatteras and over va beach to off the va capes but then continue it north nne just a bit to perhaps just east of ocean city then a ene turn from there. And yes I realize that's almost our ideal setup but it's what the evidence suggests to me right now. 

[Bob Chill]

Just now, Ian said:

Hmm, must have missed that one. I'd have to look back at 500mb evolution but that seems like a Miller A as well. Either that or there are very few Miller As. I think Dec 2009 is widely accepted as one... although it wasn't that different than Feb 5-6. So, I dunno. I think it may be that hybrids and such are the predominant type... the Miller classification is pretty old. 

At the end of the day I don't really care what they are technically called. Theres so many hybrid type bigger events that it gets muddy. We know the ones with good potential and the ones that are fraught with peril. Thankfully the one on deck shook the fraught with peril look. We're getting saved by the southern storm doing half the work in advance compared to a classic miller b that fizzles west and bombs east. It's rare to have basically 2 storms of near equal strength so close together like this. 

[gymengineer]

2 minutes ago, Ian said:

Hmm, must have missed that one. I'd have to look back at 500mb evolution but that seems like a Miller A as well. Either that or there are very few Miller As. I think Dec 2009 is widely accepted as one... although it wasn't that different than Feb 5-6. So, I dunno. I think it may be that hybrids and such are the predominant type... the Miller classification is pretty old. 

https://www.washingtonpost.com/news/capital-weather-gang/wp/2016/01/24/the-nuts-and-bolts-meteorology-of-an-epic-snowstorm-in-washington-d-c/?tid=a_inl&utm_term=.5a1ce428faaa

Agreed that the classification has kind of moved on from beyond his original paper, which was of course based on a limited sample size.

In terms of this kind of hybrid shown by the GFS--- I wonder if the model run(s) showing DC getting over a foot in 2/95 were similar in setup. Of course it verified differently, but now I'm thinking of how was more than an inch liquid being shown in that setup. Or maybe a full phase? 

[WinterWxLuvr]

5 minutes ago, Ian said:

Hmm, must have missed that one. I'd have to look back at 500mb evolution but that seems like a Miller A as well. Either that or there are very few Miller As. I think Dec 2009 is widely accepted as one... although it wasn't that different than Feb 5-6. So, I dunno. I think it may be that hybrids and such are the predominant type... the Miller classification is pretty old. 

I think the true Miller A is rare.  I don't remember last years storm evolution but I was thinking Feb 2010 was a Miller B.  I think of a Miller A as a Jan 96 or a March 93, something that develops in the gulf and comes north.  I could be wrong tho.

[clskinsfan]

2 minutes ago, gymengineer said:

Interesting. Maybe only to me, lol, since I dredged up that discussion this week too. I noticed Halverson writing for you guys described last January's blizzard as following "the evolution of a classic Miller-B." So I guess there are people who just look at whether a significant inland primary redevelops off the coast. 

I dont consider last year a Miller B. It wasnt a normal southern stream Miller A coming out of the Caribbean either. It was just a massive 500 bowling ball the bombed out when it hit the ocean. Then it stalled at just the right time for us.  It was a pretty unique storm IMO.

 

 

[hosj III]

Miller A and Miller B are really just useful concepts, not definitive categories. They can give you an idea of what to look for but if you want to sit down and sort every storm into "Miller A" or "Miller B" you will quickly realize it's impossible. 

[Ian]

10 minutes ago, Bob Chill said:

At the end of the day I don't really care what they are technically called. Theres so many hybrid type bigger events that it gets muddy. We know the ones with good potential and the ones that are fraught with peril. Thankfully the one on deck shook the fraught with peril look. We're getting saved by the southern storm doing half the work in advance compared to a classic miller b that fizzles west and bombs east. It's rare to have basically 2 storms of near equal strength so close together like this. 

I liked the pattern.. sorta saw it from range.. tho it drifted a bit. The actual setup itself is weird in a number of ways though so it's a little counter-intuitive and has made me bearish compared to many. I'm kinda simple and love just matching height anomalies.. This one does not fit quite right at higher latitudes. That plus the disjointed nature has thrown me a bit. But I do agree that the worst parts of it have become better looking over the past 36 hours or so. So in that sense I'm starting to feel it more. 

[eurojosh]

8 minutes ago, clskinsfan said:

I dont consider last year a Miller B. It wasnt a normal southern stream Miller A coming out of the Caribbean either. It was just a massive 500 bowling ball the bombed out when it hit the ocean. Then it stalled at just the right time for us.  It was a pretty unique storm IMO.

 

 

What's interesting about that is, last year's was a storm the models caught on to from 7-10 days out, and the details hardly wavered. Which suggests that the model algorithms account more for current data than for climo and past history.

[Bob Chill]

4 minutes ago, WinterWxLuvr said:

I think the true Miller A is rare.  I don't remember last years storm evolution but I was thinking Feb 2010 was a Miller B.  I think of a Miller A as a Jan 96 or a March 93, something that develops in the gulf and comes north.  I could be wrong tho.

They really are rare. The simpleton view with coastals is we need a fairly strong storm already in process over or off the coast by NC/OBX latitude to not freak out about getting shafted. Doesn't matter if it's a transfer type storm or not. If it's not progged to get going until va beach/oc then any model run showing big snow in our yards is suspect at best. 

This storm isn't even a transfer. The southern storm is an entity all by itself before the ns gets involved. It's like a Miller a+b=c. Lol. I'm calling all future storms like this miller c's. 

[Ian]

18 minutes ago, gymengineer said:

https://www.washingtonpost.com/news/capital-weather-gang/wp/2016/01/24/the-nuts-and-bolts-meteorology-of-an-epic-snowstorm-in-washington-d-c/?tid=a_inl&utm_term=.5a1ce428faaa

Agreed that the classification has kind of moved on from beyond his original paper, which was of course based on a limited sample size.

In terms of this kind of hybrid shown by the GFS--- I wonder if the model run(s) showing DC getting over a foot in 2/95 were similar in setup. Of course it verified differently, but now I'm thinking of how was more than an inch liquid being shown in that setup. Or maybe a full phase? 

I'll have to take a look -- try to read most stuff but still miss a bit. He's really smart so I'd tend to trust him without even giving it a read.  

I'm pretty simpleton with snowstorm forecasting and snowstorm classification. I agree with Bob (even though he knows too much about the details) that the classification doesn't really matter. If it snows at my house and covers all the grass blades it's generally a good storm in my book. 

[clskinsfan]

7 minutes ago, eurojosh said:

What's interesting about that is, last year's was a storm the models caught on to from 7-10 days out, and the details hardly wavered. Which suggests that the model algorithms account more for current data than for climo and past history.

Yeah. That comes up a lot on this site. It seems like the models lock on to the big storms very well. The one thing is if the overall pattern is RIGHT for a storm. When the model pops the storm it tends to stay instead of disappear the next run. So to me the models are a lot like us. They see a favorable pattern then look to see where the SW's are and where they are going. Weather models are still one of the greatest inventions in human history to me. They are amazing actually.

[yoda]

So who's ready for the 00z NAM?

I am hoping that tonight's GFS will come into better alignment with the EURO

[RDM]

5 minutes ago, Bob Chill said:

They really are rare. The simpleton view with coastals is we need a fairly strong storm already in process over or off the coast by NC/OBX latitude to not freak out about getting shafted. Doesn't matter if it's a transfer type storm or not. If it's not progged to get going until va beach/oc then any model run showing big snow in our yards is suspect at best. 

This storm isn't even a transfer. The southern storm is an entity all by itself before the ns gets involved. It's like a Miller a+b=c. Lol. I'm calling all future storms like this miller c's. 

Interesting re the Miller C analogy.    Correct me if I'm wrong (which is likely), but it seems that the two ULLs are somehow staying fairly independent longer than normal, until they are more or less at the same lat.  Wouldn't we normally we'd expect to see one or the other dominate, with a transfer from the NS to the SJ earlier?  How is it the individual jets remain so isolated as to allow the ULLs to beat their own drum later into the equation? 

Been largely lurking here since 2002 and the typical discussions that often take place about a dual energy setup like this often focus on the timing of the energy transfer as it feeds the bombing out along the coast (or earlier if we're lucky).  Seems that is potentially going to be delayed in this setup.  If the NS energy can slow down the Southern piece, and do so soon enough, wouldn't that further stack the deck in our favor?   

Forgive if I'm missing something that is different about this setup that makes it so obviously different than the typical.  Just trying to understand at the macro level what's different about these two converging systems from the norm.  (if there is a "norm")

 

[Amped]

41 minutes ago, Amped said:

GFS and Euro are both disjointed with the 850mb low.    Euro just gives some of us a bigger paste bomb with the coastal.   Either way the northern low is going to limit the duration of the event for us. This ain't last years blizzard.

Since my earlier post wasn't displaying images. Neither EC or GFS has a good NS 850 low position at 7AM tue

[Ian]

20 minutes ago, Bob Chill said:

They really are rare. The simpleton view with coastals is we need a fairly strong storm already in process over or off the coast by NC/OBX latitude to not freak out about getting shafted. Doesn't matter if it's a transfer type storm or not. If it's not progged to get going until va beach/oc then any model run showing big snow in our yards is suspect at best. 

This storm isn't even a transfer. The southern storm is an entity all by itself before the ns gets involved. It's like a Miller a+b=c. Lol. I'm calling all future storms like this miller c's. 

This was my issue with early runs.. or one of them. Development and quick bomb close by. Not common. Models overdo deepening frequently. But in this day and age most people just rip and share without thinking about it so that solution is out there. We've been screwed on the southern end of too many Miller Bs not to know we want a developed/ing storm by the outer banks area. If nothing else we need that warm air advection shot.. we are iffy on the backside despite being good closers overall. 

Almost every run since it showed up through this morning at least had the low more and more developed earlier. Nothing supercharged early but still. Moisture, a trackable closed low etc etc.  

Euro is probably still too deep but other than that it seems relatively locked in. GFS is not good with EC storms or anything else really so it'll show something close to acceptable at least. 

I've been a little weirded out by the super high precip totals on the GFS but the biggest stuff was mainly offshore and has been toned down a bit. Something weird there more than just frontogenesis forcing. Made me think of the QPF bomb we saw on a lot of runs before the blizzard last yr. I believe that was the GFS too. 

I just don't want it to total slopfest before sunrise. I never loved Feb 2014 nearly as much as others did.. altho the late night action was fun.

[eurojosh]

6 minutes ago, Amped said:

Since my earlier post wasn't displaying images. Neither EC or GFS has a good NS 850 low position at 7AM tue

Just to put that in context, some in this forum got 30" in last year's storm. Prior to the current oddness, that would have been once in a generation. Compared to what should be normal, the chance of a foot in mid March is extremely unusual.

[Bob Chill]

@RDM - the southern vort is pretty weak but distinct as the ns vort/low approaches. The amplification in front of the ns vort sorta kick starts the southern energy to get organized and gain latitude. 

I've posted that they are independent but that isn't exactly true. The reason the southern energy turns into a storm before any phase is because the northern vort tugs on it and draws it up and in. So in that respect they are "connected".

The ultimate solution would be a phase into a single closed upper level low to our south or southwest ( but not too far west or it all runs inland). That doesn't appear likely at all and it's fine. What we're seeing now is the southern vort getting pulled and absorbed into the northern stream without a clean phase. And that's fine too because the southern storm becomes really strong before it passes our latitude. Because the northern stream is tugging on it, the precip field to the nw of the low is expansive. Without the tug you get a 12z cmc solution.