12z Model Thread 12/8

[ag3]

well you included philly into it to, so thats why i commented. But that map doesnt even show phl and rdg and abe getting that much

Well that map is from hour 114-126. Doesnt catch the precip from when Philly switches at around hour 113 (according to u.)

Text soundings will show the exact precip after hour 113.

[BL03]

the SE winds are screaming....yikes!

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_ten_102m.gif

[Analog96]

It looks more like .1-.2 l.e. to me after a switch to frozen, but that's splitting hairs. With temps plummeting that would quickly switch the rainy ugliness to a wintry scene. At the very least it's nice to have a backup plan to hope for if we don't get the whole thing.

But for good wraparound I want a more consolidated mid-level center where the surface low doesn't shoot so far and fast northward (maybe something like the 6z dgex). I want to be NW of BGM for this one.

I would almost prefer the snow fell on the back side, so that we could see how cold it can get with snowcover.

[ag3]

That map you posted shows the same in NYC as it does in PHL. There has been a discontinuity between gridded data and graphical data since the upgrade, with gridded data usually being correct. I don't know why.

Philly switches to snow a little before that. The text soundings will show how much precip Philly receives from hour 112-114.

[tombo82685]

It looks more like .1-.2 l.e. to me after a switch to frozen, but that's splitting hairs. With temps plummeting that would quickly switch the rainy ugliness to a wintry scene. At the very least it's nice to have a backup plan to hope for if we don't get the whole thing.

But for good wraparound I want a more consolidated mid-level center where the surface low doesn't shoot so far and fast northward (maybe something like the 6z dgex). I want to be NW of BGM for this one.

the 3hr increment between 114-117 phl has .1-.25, and they switched before 114 looking at the 925 mb temps which are already at -4 and the front past them

[Sundog]

The way we've been talking about this, it seems like it should already be here.

Indeed people were saying the storm was not happening 160 hours out. I think people forgot how easily things can change in a that much time on the models. Even 114 hours is an incredible amount of time to see things change, whether those changes are positive or negative.

[Quakertown needs snow]

One thing that has been consistent is the brrrrrrrrrrrr

http://www.nco.ncep....fs_850_144s.gif

[Chris L]

the 3hr increment between 114-117 phl has .1-.25, and they switched before 114 looking at the 925 mb temps which are already at -4 and the front past them

At least the low levels are cold enough with this case at 925 to 950 mb...

[NJwinter23]

thats not right... i have 3 hrs increments on here and between hr 114-117, .1-.25 falls from northern delaware north. with .25-.5 from lancaster to abe and lancaster to selinsgrove north. nyc may get shafted a little more do to the low placement being closer, but they atleast see .1 in qpf

shall pull up bufkit when the run is finished.

I'm not sure how much better we can do than this solution, despite still being 0ver 100 hrs away. All of the difference appears to be with the shortwave/polar vortex interaction. The fact remains that where the polar vortex is positioned in Canada, we cannot get a confluence zone in Quebec and a surface hp in the ideal spot. East/southeast winds will rule the start of this storm. However, this is encouraging for the prospects of rain changing to snow, which was always still on the table especially for the northwestern suburbs of the cities. I'd still be weary of a se bias here though, pending the other model runs.

Then again, crazier things have happened 114hrs out so we'll see.

[Analog96]

shall pull up bufkit when the run is finished.

I'm not sure how much better we can do than this solution, despite still being 0ver 100 hrs away. All of the difference appears to be with the shortwave/polar vortex interaction. The fact remains that where the polar vortex is positioned in Canada, we cannot get a confluence zone in Quebec and a surface hp in the ideal spot. East/southeast winds will rule the start of this storm. However, this is encouraging for the prospects of rain changing to snow, which was always still on the table especially for the northwestern suburbs of the cities.

Then again, crazier things have happened 114hrs out so we'll see.

What we would really need is the primary to shift a little S & E and the secondary to form sooner.

[tombo82685]

where i get the gfs from has a snow map with it...here are the snow amounts through 117. western burbs do the best.

rdg 4-8

abe 4-8

phl 2-3

ilg 2-3

ttn less than 2

nyc less than 2

[Chris L]

One thing that has been consistent is the brrrrrrrrrrrr

http://www.nco.ncep....fs_850_144s.gif

That is very close to the 2004 cold blast with the core of the cold in SE Canada and the orientation of the troughness.

[eduggs]

thats not right... i have 3 hrs increments on here and between hr 114-117, .1-.25 falls from northern delaware north. with .25-.5 from lancaster to abe and lancaster to selinsgrove north. nyc may get shafted a little more do to the low placement being closer, but they atleast see .1 in qpf

Very cool if true. Weird that this doesn't correspond with NCEP graphics.

[BL03]

the lack of a real 50/50 low set-up pre-storm is a big problem for the coast.... unless things change the SE winds are gonna kill any snow chances until the winds switch.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_078m.gif

[Analog96]

Dont get me wrong I'm all for snow, but is anyone else a little more excited about potential brutal cold outbreak? I guess with all the snow last year and less cold I am more hyped for brutal cold, granted snow cover would help that too, so bring on both!

Like I said, yes, but I want to have some snow on the ground, so we can really see how cold it can get.

[ag3]

Very cool if true. Weird that this doesn't correspond with NCEP graphics.

Very weird that NCEP has different precip amounts. NCEP has less then .1" total for Philly and NYC from 114-126. And for KABE, only about .15".

[eduggs]

I would almost prefer the snow fell on the back side, so that we could see how cold it can get with snowcover.

Can you estimate for us?... -20C at 850, calm winds (theoretically), clear skies, 2" powdery fresh.

Single digits?

[tombo82685]

heres the skew t just nw of phl at hr 114

[NorEaster27]

The biggest story I see is very strong winds on the backside of the storm is strong CCA and tight PG, anyone else?

[SnowGoose69]

Can you estimate for us?... -20C at 850, calm winds (theoretically), clear skies, 2" powdery fresh.

Single digits?

NYC might get to about 8 in that during December...the calm winds are the problem there....the coldest nights there will happen with strong cold advection with a 20 mph wind.

[tombo82685]

heres the snowfall map through hr 120

[cleetussnow]

true... i'm not buying it yet but nice to see

this is a 5 day threat now. If you bought into the preceding model runs, that is an even bigger mistake. I didn't take much stock in the snowy solutions from last weekend, but way more interested now. There really isn't a whole bunch of similiarities between the 8-10 day progs for this event and what is there on the 12Z GFS anyway. Its really a whole new ball of wax.

[Chris L]

Can you estimate for us?... -20C at 850, calm winds (theoretically), clear skies, 2" powdery fresh.

Single digits?

Below Zero. It is possible given the setup you are talking about.

But the winds gusting 15-20 mph will hurt.

[tombo82685]

Tombo can you do LNS for me?

you are prob a little less more like 3-6

[NorEaster27]

SYR gets another 1-2 feet to add on the 30 inches on the ground, followed by 20-30 inches in LES behind the storm.

[Chris L]

SYR gets another 1-2 feet to add on the 30 inches on the ground, followed by 20-30 inches in LES behind the storm.

Now that is incredible. Seriously, what is their record snow depth?

[NJwinter23]

What we would really need is the primary to shift a little S & E and the secondary to form sooner.

Sure, that could definitely help our cause. Also if the polar vortex was positioned further southeast, and the wave was less amplified we would be in much better shape too, even without a 50/50 low or the classic setup. But this would have to be pretty substantial even at 114hrs out. There is no avoiding the screaming east/southeast winds at the start of this thing in my opinion. 2nd half of the storm is still up for grabs though I'll admit.

[BL03]

SYR gets another 1-2 feet to add on the 30 inches on the ground, followed by 20-30 inches in LES behind the storm.

yea 1-2' of real wet snow on top of that 30"+ dry stuff would prob close the city down.

[Feb]

hmmm...interesting 12z UKMET has shifted significantly southeast. Looks like a coastal hugger...maybe from ACY to the CC Canal?

I only have the thinned in at the moment...I'll wait until the full resolution comes in to be certain...

From the New England thread.

[Alpha5]

Low literally tracks over NYC, not going to see much snow with that track but its a start.

Id like to see the clipper weaker and further to the north, then establishing itself near 50/50.

Otherwise the trends are good

Folks: Were over 100 hours away from this and the low needs to track just a bit further east (eastern LI would be good for NYC and surrounding areas).

Places further west seem to be in a better spot with this, reminds me of the snowicane a bit