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Days and days of snow disco

Damage In Tolland

By Damage In Tolland,
in New England

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powderfreak

powderfreak

Posted
Posted
4 minutes ago, CoastalWx said:

We hope it's right.

Do these things usually evolve as a band of snow or is it a more general snow shield pushing onshore and enhancing around the coastal front and speed convergence from land-sea interaction?  

Or is it like lake effect and you get a band wobbling north or south with the flow?  

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CoastalWx

CoastalWx

Posted
Posted
4 minutes ago, powderfreak said:

Do these things usually evolve as a band of snow or is it a more general snow shield pushing onshore and enhancing around the coastal front and speed convergence from land-sea interaction?  

Or is it like lake effect and you get a band wobbling north or south with the flow?  

I this case, you'll have two things going on I think. One is the CF enhancement from cold N winds near BOS where it will be in the U10s and just east, temps will be near 30 with NE winds. Just off the deck you'll have 30kt winds from the due east above 950. So you have air moving up and over the CF and blown west a bit. With the salt nuclei, you can get good dendrites near -8 to -10C.  It's this phenomenon that helped lead to ridiculous totals in the Feb 2015 long duration storm.

 

You'll also have the land sea convergence which favors the Rt3 corridor of Plymouth county. These are usually bands, with a nice band seemingly always favoring the Scituate/Marshfield area up to Norwell/Hanover.You have some low level instability below the inversion height around 850mb. Terrain going up to over 200', and as you said..land sea convergence. So,that NAM map makes sense...just not sure if it's over my fanny..or just east of me.

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Ginx snewx

Ginx snewx

Posted
Posted
7 minutes ago, CoastalWx said:

I this case, you'll have two things going on I think. One is the CF enhancement from cold N winds near BOS where it will be in the U10s and just east, temps will be near 30 with NE winds. Just off the deck you'll have 30kt winds from the due east above 950. So you have air moving up and over the CF and blown west a bit. With the salt nuclei, you can get good dendrites near -8 to -10C.  It's this phenomenon that helped lead to ridiculous totals in the Feb 2015 long duration storm.

 

You'll also have the land sea convergence which favors the Rt3 corridor of Plymouth county. These are usually bands, with a nice band seemingly always favoring the Scituate/Marshfield area up to Norwell/Hanover.You have some low level instability below the inversion height around 850mb. Terrain going up to over 200', and as you said..land sea convergence. So,that NAM map makes sense...just not sure if it's over my fanny..or just east of me.

Great explanation,  took a while for people to grasp the salt nuclei factor. Good stuff 

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powderfreak

powderfreak

Posted
Posted
16 minutes ago, CoastalWx said:

I this case, you'll have two things going on I think. One is the CF enhancement from cold N winds near BOS where it will be in the U10s and just east, temps will be near 30 with NE winds. Just off the deck you'll have 30kt winds from the due east above 950. So you have air moving up and over the CF and blown west a bit. With the salt nuclei, you can get good dendrites near -8 to -10C.  It's this phenomenon that helped lead to ridiculous totals in the Feb 2015 long duration storm.

You'll also have the land sea convergence which favors the Rt3 corridor of Plymouth county. These are usually bands, with a nice band seemingly always favoring the Scituate/Marshfield area up to Norwell/Hanover.You have some low level instability below the inversion height around 850mb. Terrain going up to over 200', and as you said..land sea convergence. So,that NAM map makes sense...just not sure if it's over my fanny..or just east of me.

Nice summary... this is just what I was looking for.  Thanks.

And you answered my next question about the salt nuclei variable.  I was wondering how that affects snow growth and how it might help/hurt ratios.  Seems like it lowers the temperatures where you can get good DGZ?

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CoastalWx

CoastalWx

Posted
Posted
3 minutes ago, powderfreak said:

Nice summary... this is just what I was looking for.  Thanks.

And you answered my next question about the salt nuclei variable.  I was wondering how that affects snow growth and how it might help/hurt ratios.  Seems like it lowers the temperatures where you can get good DGZ?

Yep, and they provide a nice nuclei to form crystals on.

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OceanStWx

OceanStWx

Posted
Posted
37 minutes ago, powderfreak said:

Do these things usually evolve as a band of snow or is it a more general snow shield pushing onshore and enhancing around the coastal front and speed convergence from land-sea interaction?  

Or is it like lake effect and you get a band wobbling north or south with the flow?  

To piggy back on Scott's nice summary, the tendency is for multi-band. A strong single-band requires some added convergence from land breezes (i.e. the north and south shores of Lake Ontario) to focus the band. In the absence of those land breezes you get alternating rows of updraft/downdraft in shallow convection.

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ORH_wxman

ORH_wxman

Posted
Posted

The salt nuclei raises the temps where good snow growth can happen. Like if you have a very dense concentration of salt nuclei then you can get dendrites even at -5 and -6c. There's some good papers on the subject I've read over the years. But OES is an obvious example where the salt nuclei might be quite dense. 

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CoastalWx

CoastalWx

Posted
Posted
25 minutes ago, OceanStWx said:

To piggy back on Scott's nice summary, the tendency is for multi-band. A strong single-band requires some added convergence from land breezes (i.e. the north and south shores of Lake Ontario) to focus the band. In the absence of those land breezes you get alternating rows of updraft/downdraft in shallow convection.

The nice events are those multi bands that sometimes migrate west with time.  But much of the time within a synoptic snow shield it’s just some enhancement. Sometimes you’ll see a cellular nature of heavier echoes flying SW on radar embedded in ththe synoptic snow shield.

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OceanStWx

OceanStWx

Posted
Posted
1 minute ago, CoastalWx said:

The nice events are those multi bands that sometimes migrate west with time.  But much of the time within a synoptic snow shield it’s just some enhancement. Sometimes you’ll see a cellular nature of heavier echoes flying SW on radar embedded in ththe synoptic snow shield.

Those are the best. PYM in its own private CJ while the rest of the world is none the wiser when they look at the larger radar presentation.

There does seem to be some potential for a little backing of the wind just ahead of the first wave that may bring some of this onshore. I have a little bit of chance PoP in far southern NH. Maybe a Hampton Toll "surprise" dusting. 

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wxeyeNH

wxeyeNH

Posted
Posted
1 hour ago, Damage In Tolland said:

So many places snow Mon- Wed and possibly Thursday. That’s meh?

Not expecting days and days of snow up here.  This is a meh for the few of us up here in nowheresville NH.  Yeah the title should be changed to mid-January New England snow threats....

 

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