December Discussion Thread

[REDMK6GLI]

Still several inches..little melting so far in shaded areas

 

[green tube]

Still several inches..little melting so far in shaded areas

 

 

there's still a surprising amount of snow/ice on the ground here too.  low sun angle, frozen ground and the snow itself was largely solid ice, so melting today was limited.  i was just walk walking down the street 15 minutes ago and pretty much every yard is 80 to 100% snow covered.

[Absolute Humidity]

Grassy snows are all but gone here today. It was a good run. Only shovel piles remain.

[JERSEYSNOWROB]

Grassy snows are all but gone here today. It was a good run. Only shovel piles remain.

80% of my front and back yard still snow covered like green tube. Amazing considering you're just a few miles away. I'll assume mine will be gone by tomorrow though.

[LnbWx]

80% of my front and back yard still snow covered like green tube. Amazing considering you're just a few miles away. I'll assume mine will be gone by tomorrow though.

 

I'm surprised that snowpack is still going strong here in Maywood. But I see the pack losing its thickness. Most probably will be gone by dusk tomorrow.

[Absolute Humidity]

80% of my front and back yard still snow covered like green tube. Amazing considering you're just a few miles away. I'll assume mine will be gone by tomorrow though.

I believe the primary reason for this has to do with that open wave event we had back on the 10th. The main deform band stopped literally 1/4 mile east and north of my location, where as I only received 2.5" snow. The streets on the north side of town easily saw 3.5 to 4.5" that day. Generally speaking, that 1 to 2" deference was a big deal when our Dec 14th event flipped over to rain. I had about 4 to 5" on the ground at that time (not very deep) and thus lost about 50% snow cover due to the rain and brief temp spike. That being said, the extra 1 - 2" you had makes a big difference in retaining your snow pack.

[IsentropicLift]

The 00z NAM was a solid 1.5-1.75" rain event for this weekend into Monday

[JERSEYSNOWROB]

I believe the primary reason for this has to do with that open wave event we had back on the 10th. The main deform band stopped literally 1/4 mile east and north of my location, where as I only received 2.5" snow. The streets on the north side of town easily saw 3.5 to 4.5" that day. Generally speaking, that 1 to 2" deference was a big deal when our Dec 14th event flipped over to rain. I had about 4 to 5" on the ground at that time (not very deep) and thus lost about 50% snow cover due to the rain and brief temp spike. That being said, the extra 1 - 2" you had makes a big difference in retaining your snow pack.

and just like that we are down to what, 10%?? Wow my snowpack took a beating overnight.

[doncat]

Nam and gfs still differing on frontal passage on monday with the nam slower and much wetter.

[Metsfan]

The Euro and GFS ensemble means have the same look for the first week of January

with the PV situated near Northern Hudson Bay. This would probably support a cold

front passage for us with -5 to -10 daily departures behind it. We would need to see

increased blocking near the pole or Greenland to get the PV down to near James Bay 

for a more significant cold shot here. it will be something to watch for on the ensembles

going forward.

 

gfs-ens_z500a_nhem_61.png

That's a pretty good -epo. Should lock some cold air for the conus.

[Heisy]

Upcoming pattern could be cold, but I don't see any chance of a "large" snowstorm unless we can get the PV to move a bit East. 

[IntenseBlizzard2014]

Upcoming pattern could be cold, but I don't see any chance of a "large" snowstorm unless we can get the PV to move a bit East. 

 

Could be one of those unexpected moments. That's been the theme for this winter so far. Reminds me of the classic winters. 

[PB GFI]

Snow showers of Christams day ? , would be a nice touch . The GFS is south with this The NAM is a little North . Gone is what the Canadian showed 2 days ago ,

But this would be nice for the kids to see  ( and me ) .  After this , the dam may break and the coldest air of the year heads our way for 2 weeks . When you hook the heights from over the pole

down thru the Pacific you trap the  PV and it could just and  spin in Canada , ( yes blocking would be great ) then it cant escape east over time .

 

I disagree that you want to see it displaced even further south ( I understand  only for temp reasons )  but if you do  you will cut the southern jet  completely off and  your just frigid and dry . With a PV that close 

if the SE ridge can turn moisture N then your in line for Ice and Snow  and the SE ridge should be there if lone looks at the ridging in Europe  .

Just get the cold here , worry about systems as they come .

[REDMK6GLI]

Snow showers of Christams day ? , would be a nice touch . The GFS is south with this The NAM is a little North . Gone is what the Canadian showed 2 days ago ,

But this would be nice for the kids to see ( and me ) . After this , the dam may break and the coldest air of the year heads our way for 2 weeks . When you hook the heights from over the pole

down thru the Pacific you trap the PV and it could just and spin in Canada , ( yes blocking would be great ) then it cant escape east over time .

I disagree that you want to see it displaced even further south ( I understand only for temp reasons ) but if you do you will cut the southern jet completely off and your just frigid and dry . With a PV that close

if the SE ridge can turn moisture N then your in line for Ice and Snow and the SE ridge should be there if lone looks at the ridging in Europe .

Just get the cold here , worry about systems as they come .

Sounds promising but i wont get too excited unless i see a bit of blocking develop atleast to help lock that cold air in when storm threats possibly do happen and especially spawned from the southern jet.

[nzucker]

That's a pretty good -epo. Should lock some cold air for the conus.

I like that ridge bridge developing...-EPO connecting with -AO and weak Greenland blocking.

[Isotherm]

The Euro and GFS ensemble means have the same look for the first week of January

with the PV situated near Northern Hudson Bay. This would probably support a cold

front passage for us with -5 to -10 daily departures behind it. We would need to see

increased blocking near the pole or Greenland to get the PV down to near James Bay 

for a more significant cold shot here. it will be something to watch for on the ensembles

going forward.

 

gfs-ens_z500a_nhem_61.png

 

 

 

I think you're underestimating the potential cold with this pattern.

 

The stretch December 11th-14th at Newark NJ featured 4 consecutive days of -10 to -15 departures with the below 500mb set-up.

 

11  33  23  28 -10 

12  28  20  24 -14 

13  35  17  26 -11 

14  32  20  26 -11

 

 

 

 

 

If the current model projections are correct, we might see higher heights across the Arctic than we did during the mid December cold shot. I'm not sold on any height rises in the NAO region yet, but it looks like we could possibly see the negative EPO ridge become poleward enough to connect the high heights across the pole into Asia. That pattern, if it comes to fruition, would likely be a colder one than we've seen thus far, even without any -NAO.

[IntenseBlizzard2014]

I think you're underestimating the potential cold with this pattern.

 

The stretch December 11th-14th at Newark NJ featured 4 consecutive days of -10 to -15 departures with the below 500mb set-up.

 

11  33  23  28 -10 

12  28  20  24 -14 

13  35  17  26 -11 

14  32  20  26 -11

 

 

 

 

 

If the current model projections are correct, we might see higher heights across the Arctic than we did during the mid December cold shot. I'm not sold on any height rises in the NAO region yet, but it looks like we could possibly see the negative EPO ridge become poleward enough to connect the high heights across the pole into Asia. That pattern, if it comes to fruition, would likely be a colder one than we've seen thus far, even without any -NAO.

 

Even a Neutral NAO will give us negative double departures for a extended period of time. 

[SnoSki14]

The -EPO (creates strong source of cold air) plays more of role when it comes to cold than the NAO, the AO can play a role to some extent but clearly a -EPO is able to overrule the other two. The NAO is primarily responsible for forcing some of that cold air south towards us as the jet stream bends south under us, but if you have a massive source of cold air and strong Pacific ridging, then you'll get cold air even without the NAO.

 

If the PV depiction is correct as shown by the ensembles, then we'll have a lot of cold air in January and the neutral or positive NAO could help us out as it'll prevent the PV from becoming overwhelming and we could still see storms as there will be some SE ridging still out there.

[Isotherm]

Out at D 15, if the ECMWF ensembles are correct, we kick off 2014 with brutally cold air in the MW and NE US. -EPO/-AO couplet with height rises pressing southward even into Greenland. PV situated near Hudson's Bay.

 

[REDMK6GLI]

Out at D 15, if the ECMWF ensembles are correct, we kick off 2014 with brutally cold air in the MW and NE US. -EPO/-AO couplet with height rises pressing southward even into Greenland. PV situated near Hudson's Bay.

If that verified we'd be looking at a nice cold pattern and some snow chances as well. If the NAO can atleast go nuetral we may be able to pull a rabbit out of the hat so to speak as getting out first legit winter storm along the east coast this winter. I guess like PB GFI said if we have the cold the storms will come especially with this setup

[Isotherm]

One reason I'm a bit reluctant to buy into the -AO yet is the fact that 70mb temperatures continue to cool in the stratosphere, which argues for the maintenance of a +AO. 70mb temps don't always correlate nicely with the 500mb level, so we'll see. Just would like to see this progged a bit closer in, as I could see the -AO lessening as we approach the time frame.

[PB GFI]

The one thing people miss is that KU storms are rare at the mid latitudes on the coastal plain .  Cold and dry sucks , so does rain and 60 .

You may not  see the NAO go NEG for a while , but if does West based vs East based will  matter .

Perfect set ups are rare , take what you can get .

 

Before one day the EPO goes POS and the PNA goes NEG and there`s nothing bust west winds flying across the country . That's more

common than KU`s here .

 

Think week 2 a nice gradient pattern could develop . Def a better look for New England , but that's low level cold so it may hang a little tougher .

 and as long as the flow is WSW to ENE  , you may luck out .

[wolfsheepsheadbay]

12z euro shows a snowstorm for nye.

[earthlight]

Out at D 15, if the ECMWF ensembles are correct, we kick off 2014 with brutally cold air in the MW and NE US. -EPO/-AO couplet with height rises pressing southward even into Greenland. PV situated near Hudson's Bay.

 

 

Yesterdays GEFS ensemble analog dates were kicking off some very cold anomalies at 2m and 500mb over much of the Northeast by the end of the first week of January. Today looks like much of the same.

 

http://www.meteo.psu.edu/~fxg1/ENSHGTAVGNH_12z/f240.gif

[Allsnow]

12z euro ensembles are frigid for the start of January

[alwaysready126]

Cold and dry.

[NEG NAO]

This is dramatic - we go from mid - summer 850 levels of +16 to mid winter 850 levels of -17 in a 57 hour time range - don't see that too often...

 

http://68.226.77.253/text/NAMSFC/NAM_Knyc.txt

[Absolute Humidity]

Snow showers of Christams day ? , would be a nice touch . The GFS is south with this The NAM is a little North . Gone is what the Canadian showed 2 days ago ,

But this would be nice for the kids to see  ( and me ) .  After this , the dam may break and the coldest air of the year heads our way for 2 weeks . When you hook the heights from over the pole

down thru the Pacific you trap the  PV and it could just and  spin in Canada , ( yes blocking would be great ) then it cant escape east over time .

 

I disagree that you want to see it displaced even further south ( I understand  only for temp reasons )  but if you do  you will cut the southern jet  completely off and  your just frigid and dry . With a PV that close 

if the SE ridge can turn moisture N then your in line for Ice and Snow  and the SE ridge should be there if lone looks at the ridging in Europe  .

Just get the cold here , worry about systems as they come .

0Z NAM now has the mood flakes and has a narrow .1+ stripe from NE NJ through the city and Nassau.

[SnowGoose69]

0Z NAM now has the mood flakes and has a narrow .1+ stripe from NE NJ through the city and Nassau.

 

The setup from 500-850 is very good for inverted trof formation with very light winds within the trof at all layers but as always who the hell knows where its going to setup

[uncle W]

other years with such warmth and snow in late December was 1984 and 1990...I like 1990-91 as the prime analog now...The January 11-12th 1991 storm gave us similar results as the 5" of snow that fell earlier this month that changed to rain...1984 had a snowstorm between torch's and 1990 the same...this year it's one torch but a doozy...