Potential Winter Storm March 6-7

[JSantanaNYC]

David-LI, on 01 Mar 2013 - 00:53, said:

Isn't the energy still over the pacific ocean? Don't models hand storms better once they enter the continental US? 

Yes. The S/W won't be over Seattle until 84 hrs from this morning's 6z model run ( you do the math, I'm too tired to).

[Zelocita Weather]

EURO maybe gets 0.25-0.5" up to Rt.78 or so from what Im gathering from other threads?

[Dsnowx53]

Yeah, there is no real northern stream energy that this phased with. Some small embedded vorts in the flow helped, but this wasn't a pure northern stream capture type of thing.

 

This run was cold because the block shifted to the west just a bit. That allows the high pressures to supply a continental NE wind as opposed to one that is a bit more marine tainted.

 

So, I think it's a good sign that the Euro was cold this run, and still was pretty close to crushing us. DC appears to get all snow. 

[Weathergun]

The block shifted to the west a bit. But nowhere near as far west as some runs a couple of days ago. It's still in a pretty decent position, as it eventually does bridge with the SE ridge. But its shift to the west definitely helped suppress this a bit.

The block a bit to the west also helps our cold air source be more continental than marine, though, so we were colder. So I'd almost prefer just a tick east with the block, rather than fully going back to where we were last run.

 

I honestly didn't see THAT much northern stream interaction, though, but I'll look again. 

 

There's far less northern stream interaction on this run:

 

[Snow_Miser]

EURO maybe gets 0.25-0.5" up to Rt.78 or so from what Im gathering from other threads?

That's what it seems to be looking off the text, yes. It's good in the fact that it's colder, but we just need more precip. As Doug said, what would be ideal is if the -NAO block shifted slightly to the east, so that there would be a colder solution than the 00z run, but more precipitation than the 12z run.

[CooL]

Northern stream is lacking on the euro

[SnoSki14]

Yeah, there is no real northern stream energy that this phased with. Some small embedded vorts in the flow helped, but this wasn't a pure northern stream capture type of thing.

 

This run was cold because the block shifted to the west just a bit. That allows the high pressures to supply a continental NE wind as opposed to one that is a bit more marine tainted.

 

So, I think it's a good sign that the Euro was cold this run, and still was pretty close to crushing us. DC appears to get all snow. 

 

It's a good sign because we'd rather have it further away from us than the gfs/ggem show. A strong storm tucked in close to our coast is a heavy rain disaster. 

[Dsnowx53]

There's far less northern stream interaction on this run:

 

12zECf144.gif

 

 

The 00z Euro didn't really have much northern stream interaction, either. 

[Zir0b]

This is another pretty big shift by the Euro run-to-run, very little continuity with all the global models...only thing that can be said with a higher degree of confidence is that there will be a strong low pressure system on the east coast next week, the track/intensity/thermal profiles will look more clear no earlier than the 0z UTC  Monday runs, when most of the variables at play are going to be in a well-sampled data region. Until then I expect a lot of waffling back and worth and sideways

 

[Dsnowx53]

That's what it seems to be looking off the text, yes. It's good in the fact that it's colder, but we just need more precip. As Doug said, what would be ideal is if the -NAO block shifted slightly to the east, so that there would be a colder solution than the 00z run, but more precipitation than the 12z run.

 

 

I think it's good that despite the airmass not being super cold, there are multiple ways for us to get colder than the warmest model runs:

 

1) The block shifting to the west a bit. (we don't want too much of this, or we get suppression, but it does help and there is some wiggle room with this)

2) More phasing or a true phase with the northern stream.

3) Both. 

 

The shifting of the block can also affect the track of the storm itself as well, so I didn't use a different track as #4. 

[NaoPos]

yeah, my fault guys.... i thought full phase at first, but its just a full capture instead. My bad.

[Zir0b]

Euro snow maps shows the bullseye in the DC region with 12-18", with a small spot of 18"+ in Central VA. 

 

[Zelocita Weather]

How much if any in N NJ/NYC OFF THE euro snowmaps?

[Snow_Miser]

Excellent agreement for a 120 forecast from the GFS ensembles, Euro, and UKMET.

 

12zgfsensemble850mbTSLPUS120.gif

 

12zeuro850mbTSLPUS120.gif

It's only after there where the divergences become pretty large. The UKMET/ECMWF are both southern solutions, and the GFS/GGEM are northern solutions. None of these solutions are set in stone, and are almost guarenteed to change again, since the model runs have been shifting pretty considerably in some cases from run to run.

[ace0927]

How much if any in N NJ/NYC OFF THE euro snowmaps?

zero (MAPS PULLED OFF OF DT's FB page - not sure if this is allowed on here)

 

[WintersGrasp]

Doesn't it look like an amped up system chugging up along the coast that would force colder air into the system AND there is a strong high to the north ? Why not mainly snow ?

[Zelocita Weather]

I could be wrong here but I bieleve thats only through a certain time. S NJ gets mucho QPF and shows nothing there on the model. I think you have to extend everything east to get the whole storm.

[Storm At Sea]

Euro is right where we want it. No way does va get 12+. Just like every other coastal storm this yr it will trend north w time. People have short memories.

[ace0927]

I could be wrong here but I bieleve thats only through a certain time. S NJ gets mucho QPF and shows nothing there on the model. I think you have to extend everything east to get the whole storm.

the left one is QPF, see the green blob down in S NJ...now refer to the SNOW map...assumption, that precip is anything BUT snow.

[ace0927]

Euro is right where we want it. No way does va get 12+. Just like every other coastal storm this yr it will trend north w time. People have short memories.

see the maps I posted of the March 6-8 1962, Ash Wednesday storm. Setup is eerily identical.

[green tube]

I could be wrong here but I bieleve thats only through a certain time. S NJ gets mucho QPF and shows nothing there on the model. I think you have to extend everything east to get the whole storm.

 

the snow panels on wunderground for the euro arent any better, fwiw.  zippo.

[JSantanaNYC]

Its funny, the Euro has change on every run.. and people are still arguing who gets what, 6 days out.

[Zelocita Weather]

^{If you take the spray off all the models and all their gyrations over the past couple days and the pattern, I think chances diminish for a sizeable snowstorm once north of S NY State/S CT/S RI / NE PA or south of S/C VA. Anyone in between has a shot, whether it is Richmond or NYC that gets the most is still up for grabs.}

[earthlight]

12z Euro ensembles take a sub 1000mb low off OBX just east-northeast. Looks like a decent amount of precipitation up this way as well. The operational falls south of the mean h5 trough.

[Storm At Sea]

I just reviewed/compared the two setups. One thing that stands out quite abruptly...Lowest H5 heights were further south for the 1962 storm...meanwhile, for this storm, most of the modelling show the lowest H5 heights to be as far south as WVA and S VA. That is significant.

 

see the maps I posted of the March 6-8 1962, Ash Wednesday storm. Setup is eerily identical.

[NEG NAO]

see the maps I posted of the March 6-8 1962, Ash Wednesday storm. Setup is eerily identical.

that's the last analog we want to verify - severe damage to the jersey shore and no snow in NYC metro - honestly models won't have a handle on this till the system comes ashore later this weekend out west

[PB GFI]

This gets onto the west coast tomorrow so there will be a little better sampling. Great continuity on the surface coming to HSE It does bomb. It is slow. And it should be moist. Over the next 3 days all the models have to agree on is at what latitude does it caught in.

Yesterday at this time it was atlanta to Roanoke. Today the bullseye is DC. So let's wait for it get on the grid and a day or 2 of measuring where the block is centered. In a best case scenario I don't see this as a blockbuster snow event for the coast unless the center can get south of long island so our winds are NE and no models is close to that . Any feature that sits from the CNJ coast to AC to the mouth of Deleware bay our winds are EAST and ur a little to toasty on the coast.

However once away from the coast especially from Trenton thru Philly into DC ths could b a show.

As it is you may see winds gust to hurricane force as far north as NJ coast and no one needs that

[KEITH L.I]

that's the last analog we want to verify - severe damage to the jersey shore and no snow in NYC metro - honestly models won't have a handle on this till the system comes ashore later this weekend out west

in march 62 it rained here or was it dry?

[Edge Weather]

Two things I have noticed with the models so far with this potential.  One is that the NAVGEM came out with much farther northern solutions, then the Euro did so.  Then the NAVGEM came out with a more southern solution, and now the Euro did.  The same thing is true of the Euro Control run, but to a letter degree than with the NAVGEM.  In other words, right now, the models that have been leading the way have been the NAVGEM and the Control run of thue Euro.  I just wonder if that will continue, but for now I am curious to see what those models do next.

[Edge Weather]

Control run of the Euro is about 100 miles or so further northwest of the operational run with the precip shield, bringing about .35 as far north as Northern NJ and NYC, .75 line probably runs from around Trenton to Asbury Park roughly.  I don't have a total precip available, so I am doing my best guess.  Anyway, it is substantially NW of the operational run.  It has a 994mb near Virginia Beach at 132 hrs. then it actually slides it SE from there, but expands the precip shield back in the wrap-around to Southern New York State and NE PA, with the good snows in the band as far north as roughtly Rt. 78 to NYC.