Jump to content
  • Member Statistics

    17,586
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

Dec 9-10 storm threat


ORH_wxman

Recommended Posts

  • Replies 2k
  • Created
  • Last Reply

Man, its close...like 12z to 15z tomorrow it could go either way. I think by midday it should be too warm in the mid-levels...but I'm pretty sure the sfc won't be above freezing at ORH by then.

 

I'd probably go an inch or two there right now. But I could see it busting into a quick 4-5" if things don't warm as fast as progged in the mid-levels.

 

One thing that makes me a bit nervous is that the warm layer is pretty low on the all the soundings...like 850-900mb. This makes it more likely to be influenced by CAD..so if models are underdoing that, then we could see the extra 3 hours of snow soundings which could really screw some forecasts up.

Dense thick air takes a while to scour out in some places.  Would that not lead to more icing than snow?

Link to comment
Share on other sites

Man, its close...like 12z to 15z tomorrow it could go either way. I think by midday it should be too warm in the mid-levels...but I'm pretty sure the sfc won't be above freezing at ORH by then.

 

I'd probably go an inch or two there right now. But I could see it busting into a quick 4-5" if things don't warm as fast as progged in the mid-levels.

 

One thing that makes me a bit nervous is that the warm layer is pretty low on the all the soundings...like 850-900mb. This makes it more likely to be influenced by CAD..so if models are underdoing that, then we could see the extra 3 hours of snow soundings which could really screw some forecasts up.

 

I just have this vision of the Rt2 corridor getting smashed with like 3-4hrs of heavy wet snow and worried ORH may not be far off. II still have to look at this harder, but I share the same concerns you have.  

Link to comment
Share on other sites

Dense thick air takes a while to scour out in some places.  Would that not lead to more icing than snow?

 

 

Yes, it is a recipe for icing...but here's where it can get a little more complicated:

 

If the elevated warm layer is only at, say, 875mb, versus like 750mb, then that 875mb elevated warm layer has to advect into an airmass that is more dammed than a 750mb layer...the cold dome at the surface will have a ripple effect up into the atmosphere above it. By the time you reach a level like 750mb (or similar), that ripple effect becomes negligible. But for a lower elevated warm layer, it is not negligible. So if the models are under-estimating the dammed cold dome at 925mb, then the elevated warm layer is going to run into that roadblock moreso than models predict as well...it will be forced to rise and cool...thus, now we have a colder sounding than was forecasted originally.

 

That is the difficult part about this setup. Just how much effect is the cold dome going to have on the soundings as we get closer? It's something that can matter for those areas with a marginal sounding on the models for several hours tomorrow AM.

 

Of course, there's other variables too...such as the lift...is it weaker or stronger than forecast? That can effect the sounding too.

Link to comment
Share on other sites

We had a similar omega thump last year in Feb. Was progged warmer ended up with a tremendous quick thump. My predicted soundings at the time were similar to Hunchies tomorrow. That's high impact stuff to if it hits the rt 2 93 corridor at rush hour

Was that on 2/14 (I think)?   That short burst of near whiteout?

Link to comment
Share on other sites

Yes, it is a recipe for icing...but here's where it can get a little more complicated:

 

If the elevated warm layer is only at, say, 875mb, versus like 750mb, then that 875mb elevated warm layer has to advect into an airmass that is more dammed than a 750mb layer...the cold dome at the surface will have a ripple effect up into the atmosphere above it. By the time you reach a level like 750mb (or similar), that ripple effect becomes negligible. But for a lower elevated warm layer, it is not negligible. So if the models are under-estimating the dammed cold dome at 925mb, then the elevated warm layer is going to run into that roadblock moreso than models predict as well...it will be forced to rise and cool...thus, now we have a colder sounding than was forecasted originally.

 

That is the difficult part about this setup. Just how much effect is the cold dome going to have on the soundings as we get closer? It's something that can matter for those areas with a marginal sounding on the models for several hours tomorrow AM.

 

Of course, there's other variables too...such as the lift...is it weaker or stronger than forecast? That can effect the sounding too.

Great post. 

Very illuminating.

 Higher bust  potential than your standard swfe that has the apex of the waa @ ~H7.

Link to comment
Share on other sites

I guess the northeastern Connecticut hills are vaguely referred to as this southern extension of the White Mountains that levels off from the Worcester hills down to the Eastern Connecticut hills but are not considered part of the Appalachians. I believe the Shenipsit Trail runs through that area as well just to the east of the Connecticut River Valley from East hampton up through Glastonbury where elevations touch near 1000 at Meshomasic state forest and then closer to 1100 near Soapstone Mountain in Somers but Kevin may be just a hair east of that I'm not sure.

 

Tolland is east of where you're talking about.  There are higher elevations in northeastern CT with portions of Stafford and Union having road elevations over over 1200'.  The highest hill is 1315' which is the highest elevation until you get north of ORH.

 

I've lived here all my life and never heard these hills be associated with the Whites....totally different geologically speaking.  Mt Ascutney, VT is geologically closer to the Whites than the greens but my understanding is that is as far south as they go. 

 

As far as I know, they do not have a name though I know that some people refer to the relatively elevated plateau as the Quinebaug Highlands.

 

That being said, I think we are out the picture for now but there might be a brief period of some interesting weather early tomorrow morning - before the morning commute.  Then it's all wet!

Link to comment
Share on other sites

Yes, it is a recipe for icing...but here's where it can get a little more complicated:

If the elevated warm layer is only at, say, 875mb, versus like 750mb, then that 875mb elevated warm layer has to advect into an airmass that is more dammed than a 750mb layer...the cold dome at the surface will have a ripple effect up into the atmosphere above it. By the time you reach a level like 750mb (or similar), that ripple effect becomes negligible. But for a lower elevated warm layer, it is not negligible. So if the models are under-estimating the dammed cold dome at 925mb, then the elevated warm layer is going to run into that roadblock moreso than models predict as well...it will be forced to rise and cool...thus, now we have a colder sounding than was forecasted originally.

That is the difficult part about this setup. Just how much effect is the cold dome going to have on the soundings as we get closer? It's something that can matter for those areas with a marginal sounding on the models for several hours tomorrow AM.

Of course, there's other variables too...such as the lift...is it weaker or stronger than forecast? That can effect the sounding too.

This is an awesome post. Worth saving that one for future reference.

Link to comment
Share on other sites

I'd be bullish route 2 on north for a thump. I just don't think it's in the cards here this time around more than an inch or two. ORH is different than here, but I still think they need more longitude. Sure, it might be marginal for a time leading to a few inches, but potential snowfall bust is way higher over the border in SNH. I guess I would go 1-2" interior ne ma, 2-4" at orh directly, an area of 4-6" for the rt 2 corridor and into southern nh where they cool dynamically and hold off warming slightly longer.

Link to comment
Share on other sites

See what bothers me is that I take the GFS soundings and cool below 900 in my head since it has a pronounced warm bias, and there is the thump. The dome will be there, it's the 850ish layer that is the issue I think.

 

 

The GFS (and even the NAM) almost warm the mid-levels from 900mb upward...like look at the 27 hour sounding for ORH on the GFS...the warmest layer is actually below 850mb.

 

di-1514180689411.png

 

 

 

 

 

 

 

Then by 30 hours, it has warmed up at 850mb but the warm layer is still clearly centered pretty low. This makes it a tougher forecast to me.

 

 

di-0141806914412.png

Link to comment
Share on other sites

Completely off-topic...but that's cool, I didn't know geologically their parent mountain range is the Whites.  I thought it was a completely seperate geological time frame.  I'll know to refer to them as the Mahoosucs now.

 

http://en.wikipedia.org/wiki/Mahoosuc_Range

 

I'm going to confuse these with Mt Moosilauke which is closest White peak to the VT border.

 

Unfortunately, I don’t think the Mahoosucs is appropriate for both Sugarloaf and Sunday River.  As if the lack of a tersely-named range over there wasn't already making it challenging enough to simplify, the mountains for the two ski resorts aren't even in the same sub-ranges until one gets all the way up to the level of the Northern U.S. Appalachians, and we know what a huge area that is.  Also note that the Wikipedia page above indicates that the Mahoosuc Range's highest peak is 4,180-foot Old Speck Mountain, and Sugarloaf is taller than that.  Anyway, the specific breakdown for the ranges from Peakbagger.com (a fabulous mountain-related resource by the way) for those wanting to figure out how to lump the two resorts.

 

Continent: North America

Range2: Appalachian Mountains

Range3: Northern U.S. Appalachians

Range4: Longfellow Mountains

Range5: Rangeley-Stratton Ranges (Highest Point)

Peak: Sugarloaf Mountain 4,240'

 

Continent: North America

Range2: Appalachian Mountains

Range3: Northern U.S. Appalachians

Range4: White Mountains

Range5: Mahoosuc Range

Range6: Bear Mountain Area (Highest Point)

Peak:  Sunday River Whitecap 3,335'

 

For comparison, the breakdown for Mt. Mansfield is bit easier:

 

Continent: North America

Range2: Appalachian Mountains

Range3: Northern U.S. Appalachians

Range4: Green Mountains (Highest Point)

Range5: Northern Green Mountains (Highest Point)

Range6: Mount Mansfield Area (Highest Point)

Peak: Mt. Mansfield 4,395'

Link to comment
Share on other sites

The GFS (and even the NAM) almost warm the mid-levels from 900mb upward...like look at the 27 hour sounding for ORH on the GFS...the warmest layer is actually below 850mb.

 

di-1514180689411.png

 

 

 

 

 

 

 

Then by 30 hours, it has warmed up at 850mb but the warm layer is still clearly centered pretty low. This makes it a tougher forecast to me.

 

 

di-0141806914412.png

 

Yeah exactly. So in my mind, if I sort of hedge cooler near 900...it may be a matter of timing the 900-850mb push. Does the NAM look warm to you at 950? That seems awfully mild at that level. Which again sucks, because you'd think mesos would be better at that. It makes me wonder if the cold wedge becomes very shallow.

Link to comment
Share on other sites

Color me skeptical on the NAM at ORH getting above 32 at 12z.

My difficulty right now is tracking this coastal front and the cold northern bleed of air down into sne. 2m temps aren't really close, none of the globals are. It's 21F out there right now! However, knowing that I am technically the 'interior coastal plain' leads me to believe it won't take much for a wind shift to toast the BL here. However, with the colder than forecasted temps and difficulty in handling coastal fronts, when will the warmer air work in? Tough to really tell, we'll see how the hires handle the transition as WAA advects in and the noreaster strengthens...

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...