Feb 1-2 storm threat

[WinterWolf]

3 minutes ago, DotRat_Wx said:

I just don't see how that 5h brings a snowstorm to SNE....... It doesn't add up. 

But that 5H may be modeled incorrect as well?  

[Hazey]

If the GFS has it's way, it will be congrats Nick soon. Latest models are putting the whiff on the table even for here. Oh course they've been doing more waffling then an IHOP so who knows.   

[Typhoon Tip]

33 minutes ago, weatherwiz said:

Wow that's a substantial difference..this northern stream is really giving the models a workout 

It seems to be the whole ball of wax on this this thing - 

Just a quick critique - you mentioned earlier that the N/stream involvement didn't seem very plausible to you "because the flow is tipping progressive" - or words to that affect. 

I don't see how/why 'progressive' characteristic of the total flow behavior is a logical delimiter there. Progressive happens in either stream...it's just a tendency for r-wave rollouts to move actively west-toward east at mid latitudes..which can be endemic to either.  

That said, "phasing" per se is harder - not so much because it can't happen, but... because the models are not sophisticated enough to handle the narrowing margins for error down to finite scales, required to correctly assess whether there is syncing mechanics in the stream spacing and so forth.  

It's a bit advanced...but, it really has to do with the coriolis forcing in three-D.   2Ω (v sinφ - w cosφ), -2Ωu sinφ, and 2Ωu cosφ, which handles the west to east in U, north south in V and W of course being up down.  Anyway, as these are combined, if any one exceeds a critical value/threshold ...the velocity of the system overwhelms the forcing and the system doesn't "feel" the exertion to rotate...or 'curve' as much. That's why fast flow tends to curve less ... ? It doesn't mean it curves none - it curves less...These factor work out to decimal forcing when you put in values for latitude and wind velocity.  So, you have to do all that at the latitude, per wind and so forth, at different levels...to get to a "syncing" phase...  

That's why these thing are tougher to phase at higher speeds... And, it is why the models have been tending to correct phasing toward the upper/outer Maritimes ...when they were first doing so closer to home when they were in the extended. It's like it's getting better data into the f term and than the field corrects to a phasing further down stream because the curvature forcing could not take place in time to get us here.  

These runs are trying to over come that by digging the N-stream sort of calving west against the eastern slope of the western ridge ... as the ridge is pressing eastward in the progressive pattern no less. Oy.  Lot of juggling here.  This behavior might try to phase things soon...mainly because that digging further west earlier on. Increasing some space in which to phase is like giving some time back the system.  

[TalcottWx]

3 minutes ago, WinterWolf said:

But that 5H may be modeled incorrect as well?  

It's the whole trof itself though. It doesn't remind me of any system that has brought significant snow in the past. It's very odd. Maybe that's one reason to hold on. But it's so damn progressive and the amount of players in the field complicate it so much. I'd feel better in Halifax NS. 

[cleetussnow]

That last storm moved hundreds of miles in just a few model cycles before game time.  Different set up, of course.  Models were steadfast prior and a miller b cut instead.  The coast should be interested in this one at least.  Inland nasomuch.  

[Baroclinic Zone]

GGEM has the low escaping east but was close to tugging back westward as the northern stream shot it.

[ORH_wxman]

Just saw the 12z runs so far. What a huge difference in northern stream on GFS and GGEM. Still not quite enough for the surface to slam us but that level of change in one run is pretty substantial inside of 84 hours. 

I saw Dendrite’s post about that little weak lead shortwave...I agree that  you almost wonder if that trends into nothing and we get something bigger behind it...of course maybe we’re just doomed to see an incredibly well-placed deepening trough produce nothing. 

[Spanks45]

It was interesting to see the CMC kick that southern wave out to sea further, followed by the northern stream developing a larger precip shield down in the Mid Atlantic....in the end it doesn't make a difference this run, but there is still time for that "system" to develop...

[Baroclinic Zone]

Just now, Spanks45 said:

It was interesting to see the CMC kick that southern wave out to sea further, followed by the northern stream developing a larger precip shield down in the Mid Atlantic....in the end it doesn't make a difference this run, but there is still time for that "system" to develop...

That's the models trying to resolve where the best forcing is in the upper levels.  Plenty time for this to either way.

[Hoth]

10 minutes ago, Typhoon Tip said:

It seems to be the whole ball of wax on this this thing - 

Just a quick critique - you mentioned earlier that the N/stream involvement didn't seem very plausible to you "because the flow is tipping progressive" - or words to that affect. 

I don't see how/why 'progressive' characteristic of the total flow behavior is a logical delimiter there. Progressive happens in either stream...it's just a tendency for r-wave rollouts to move actively west-toward east at mid latitudes..which can be endemic to either.  

That said, "phasing" per se is harder - not so much because it can't happen, but... because the models are not sophisticated enough to handle the narrowing margins for error down to finite scales, required to correctly assess whether there is syncing mechanics in the stream spacing and so forth.  

It's a bit advanced...but, it really has to do with the coriolis forcing in three-D.   2Ω (v sinφ - w cosφ), -2Ωu sinφ, and 2Ωu cosφ, which handles the west to east in U, north south in V and W of course being up down.  Anyway, as these are combined, if any one exceeds a critical value/threshold ...the velocity of the system overwhelms the forcing and the system doesn't "feel" the exertion to rotate...or 'curve' as much. That's why fast flow tends to curve less ... ? It doesn't mean it curves none - it curves less...These factor work out to decimal forcing when you put in values for latitude and wind velocity.  So, you have to do all that at the latitude, per wind and so forth, at different levels...to get to a "syncing" phase...  

That's why these thing are tougher to phase at higher speeds... And, it is why the models have been tending to correct phasing toward the upper/outer Maritimes ...when they were first doing so closer to home when they were in the extended. It's like it's getting better data into the f term and than the field corrects to a phasing further down stream because the curvature forcing could not take place in time to get us here.  

These runs are trying to over come that by digging the N-stream sort of calving west against the eastern slope of the western ridge ... as the ridge is pressing eastward in the progressive pattern no less. Oy.  Lot of juggling here.  This behavior might try to phase things soon...mainly because that digging further west earlier on. Increasing some space in which to phase is like giving some time back the system.  

 

[Spanks45]

2 minutes ago, Baroclinic Zone said:

That's the models trying to resolve where the best forcing is in the upper levels.  Plenty time for this to either way.

The GFS showed this too, just further south and less organized....nice to see the NS adding some fuel to the atmosphere

[Damage In Tolland]

All going according to AWT

[78Blizzard]

ASOUT, that 18Z EPS was a burp run.

[CoastalWx]

9 minutes ago, ORH_wxman said:

Just saw the 12z runs so far. What a huge difference in northern stream on GFS and GGEM. Still not quite enough for the surface to slam us but that level of change in one run is pretty substantial inside of 84 hours. 

I saw Dendrite’s post about that little weak lead shortwave...I agree that  you almost wonder if that trends into nothing and we get something bigger behind it...of course maybe we’re just doomed to see an incredibly well-placed deepening trough produce nothing. 

If I didn't see the srfc pattern...I would have thought we'd be in for a good one. But yeah, that lead s/w screws us. Ugh...so close. 

[ORH_wxman]

Just now, CoastalWx said:

If I didn't see the srfc pattern...I would have thought we'd be in for a good one. But yeah, that lead s/w screws us. Ugh...so close. 

Is there even a good analog for this happening like shown? It’s funny, I was parsing through the cips analogs from last night and noticed that all of the top analogs hit us hard when looking at the T+72 timeframe which is about 24 hours before the storm “hits”. 

Makes me wonder that we’re either going to see a hit or it’s going to look notably different by the time we get closer if it’s a miss. 

[Bostonseminole]

looks like some changes also on the ukie with the NS but I only see to 54hr

[TauntonBlizzard2013]

I will say... if there was ever a time to hope for a big shift at this lead... this would probably be the exact setup to see that, given all the short waves and other elements going on.

[40/70 Benchmark]

I have never seen so many huge improvements at H5 result in negligible surface improvements.. we live in NYC at the surface, 500mb benath the tug hill plateau, apparently.

[ORH_wxman]

2 minutes ago, Bostonseminole said:

looks like some changes also on the ukie with the NS but I only see to 54hr

Not gonna get it done. It’s almost like that lead southern vort is the perfect strength to screw us. If it didn’t exist then we’d probably have a big storm...if it was stronger, it would probably ride up the eastern side of the trough and hit us...but being weak it sort of just front runs ENE and whiffs is while taking the baroclinic zone out to sea. 

[Bostonseminole]

Just now, 40/70 Benchmark said:

I have never seen so many huge improvements at H5 result in negligible surface improvements.. we live in NYC at the surface, 500mb benath the tug hill plateau, apparently.

yeap, in the end  it scoots east with UK

[Sn0waddict]

1 minute ago, ORH_wxman said:

Not gonna get it done. It’s almost like that lead southern vort is the perfect strength to screw us. If it didn’t exist then we’d probably have a big storm...if it was stronger, it would probably ride up the eastern side of the trough and hit us...but being weak it sort of just front runs ENE and whiffs is while taking the baroclinic zone out to sea. 

Seems like something that would happen given how this winter has been.

[Damage In Tolland]

All positives today. Snow coming for the pessimists 

[ScituateWX]

To my untrained eye looked like the GEFS got a little better, just toggling vs 6Z who knows . Might just be putting lipstick on a pig.

[WinterWolf]

2 minutes ago, Damage In Tolland said:

All positives today. Snow coming for the pessimists 

LOL...Ya Sure.  Hope you're right?

[Chrisrotary12]

Impressive change with respect to the Northern Stream vort. But we're going to need a Boxing Day style comeback on this one.

[Baroclinic Zone]

3 minutes ago, Damage In Tolland said:

All positives today. Snow coming for the pessimists 

Still in Step 3 I see.

[WinterWolf]

Just now, Chrisrotary12 said:

Impressive change with respect to the Northern Stream vort. But we're going to need a Boxing Day style comeback on this one.

Could happen?  But those are never likely.

[Chrisrotary12]

Just now, WinterWolf said:

Could happen?  But those are never likely.

Sure. The lead vort that comes out of Mexico is such a piece of crap that it barely has an impact.

[NorEastermass128]

At work on phone, tough to follow the play by play today. 

[RUNNAWAYICEBERG]

At this point, not sure a good 12z euro run will give us any more confidence that it’s coming or not. Could be another day or two before we close the book or drool all over it.