November 2012 Observations and Discussions

[nzucker]

The GFS shows temps at 850 below 0 and surface temps in the lower 30's in Northern New Jersey. That is snow as far as I can tell. HPC has already expressed their concern in that regard. No one is lying here.

By 180 hours, almost all of NJ save High Point is above freezing at 850mb:

Also, you need 850s colder than just 0C at this time of year. Considering that it's only November, you probably want 850s of at least -2C to have accumulating snow. 850s were -3C in the deformation band that gave us a widespread 4-8" of snow with some 12" amounts on November 7th. Even then, surface temperatures were only 31F. The GFS shows surface temperatures well above freezing with very marginal 850s for the coming storm. Could it start as snow in the elevated NW suburbs? Certainly! Would it likely be a significant snowfall as depicted? Certainly not!

[West Milford Highlander]

But lets just wish for it - it's more fun that way !

By 180 hours, almost all of NJ save High Point is above freezing at 850mb:

Also, you need 850s colder than just 0C at this time of year. Considering that it's only November, you probably want 850s of at least -2C to have accumulating snow. 850s were -3C in the deformation band that gave us a widespread 4-8" of snow with some 12" amounts on November 7th. Even then, surface temperatures were only 31F. The GFS shows surface temperatures well above freezing with very marginal 850s for the coming storm. Could it start as snow in the elevated NW suburbs? Certainly! Would it likely be a significant snowfall as depicted? Certainly not!

[famartin]

The GFS shows temps at 850 below 0 and surface temps in the lower 30's in Northern New Jersey. That is snow as far as I can tell. HPC has already expressed their concern in that regard. No one is lying here.

Here are the readings for Caldwell, NJ, 850 is below 0, even at Caldwell

MON 12Z 19-NOV 3.3 -0.1 1024 90 100 0.27 564 545

MON 18Z 19-NOV 2.8 -0.1 1022 96 100 0.38 562 545

TUE 00Z 20-NOV 2.4 -0.6 1023 96 100 0.20 562 544

No, surface temps of 36-38 are NOT snow. Unlike the EC, the GFS does not have a warm bias at the surface. If anything it might have a cold bias. Regardless, that's rain, verbatim.

Might it end up being snow because of the factors you mentioned? Yes.

But snow verbatim, that is not.

[CooL]

There is no northern stream interaction and the high is weakening. I wouldn't get excited.

Finally the first mega fantasy storm on the gfs at the end of november, maybe a good pattern gets going by then

[nzucker]

No, surface temps of 36-38 are NOT snow. Unlike the EC, the GFS does not have a warm bias at the surface. If anything it might have a cold bias. Regardless, that's rain, verbatim.

Might it end up being snow because of the factors you mentioned? Yes.

But snow verbatim, that is not.

It would be close with those soundings I'll admit. It is a decent bit colder in Westchester/Rockland/Putnam/Orange than New Jersey. 850s are a bit marginal but there's probably some room for wetbulbing at the surface given the dry high pressure to the northeast. Hours 174-180 are at night. However, this is far out on the 18z GFS so it's going to change a million times. The point is that we have a signal for a strong Nor'easter trapped under a powerful blocking high just before Thanksgiving. It is probably a rain event but may have interior snow. Winds may also be an issue especially with weakened trees and power lines. We'll just have to see but some sort of event seems to be in the cards.

[Amped]

This storm reminds me of the PDII or maybe November 7th 1953 only in the H5 fields though, the surface isn't nearly as cold. It's a basic southern stream cutoff setup, the low wont bomb but the strong high to the north gives it it's punch. If it develops further north it will have better access to cold air, hence better snow chances (Probably NE of the Catskills)

[Storm At Sea]

It's November for God's sake and we just had a significant snowfall. The chances of having another accumulating snow greater than an inch is very, very low, especially since the pattern just collapsed. Folks have to stop wishcasting and accept climo. Instead of obsessively watching each GFS/Euro run for sub zero 850 mb temps, I would watch the NAO/AO instead to determine what can develop for the first week of December.

[Storm At Sea]

WTF?

This storm reminds me of the PDII or maybe November 7th 1953 only in the H5 fields though, the surface isn't nearly as cold. It's a basic southern stream cutoff setup, the low wont bomb but the strong high to the north gives it it's punch. If it develops further north it will have better access to cold air, hence better snow chances (Probably NE of the Catskills)

[Isotherm]

It's November for God's sake and we just had a significant snowfall. The chances of having another accumulating snow greater than an inch is very, very low, especially since the pattern just collapsed. Folks have to stop wishcasting and accept climo. Instead of obsessively watching each GFS/Euro run for sub zero 850 mb temps, I would watch the NAO/AO instead to determine what can develop for the first week of December.

Yeah, I really don't care what the GFS shows for 180 hrs b/c it's going to change and I highly doubt it's going to snow to accumulate in these parts through the end of November. We've lost the blocking that we had for the Nov 7th anomalous snowfall event, and the pattern going into early December looks meh to me right now. Not worst case scenario ala last year but certainly far from very favorable. I'm not seeing any real indication of sustained -AO or -NAO blocking. Stratospheric warming looks weak atm, and if one develops we'd be looking past the first week of dec I think.

[kevbo81]

to me, the biggest threat with this coastal next week is clearly the very long duration onshore flow and coastal food potential. snow would be a thread the needle thing at this point. Lundberg's column on accuweather today was a very good assessment.

[MJO812]

0z euro ensembles now have a -NAO towards Thankgiving. It has trended towards the GEFS.

[FPizz]

Sleeting at my work nead Bedminster right now

[famartin]

Tipping bucket back home got clogged with debris, manual gauge had 0.28" rain today.

[JonClaw]

There is no northern stream interaction and the high is weakening.

That's why, with a Canadian high and CAD, the 850s aren't lower?

[earthlight]

That's why, with a Canadian high and CAD, the 850s aren't lower?

You can trace back the origin of the airmass and the high pressure you're speaking of to the Eastern Pacific.

http://www.meteo.psu.edu/~fxg1/MRF_12z/mrfloop2.html

[earthlight]

Funny Euro run beyond Day 5...large noreaster with plenty of precipitation throughout the area (and assuming some wind/rough seas as well)...followed by a fujiwara and late developing second noreaster right behind it with snow showers over the region. Huge trough but no connection to the cold air so it would moderate rapidly.

That being said the GEFS and Euro in the long range are beginning to hint at some changes by the end of the month. These usually get pushed back a bit but I think we might be getting the first signs of a more blocky pattern by the beginning of December. We'll see.

[Dsnowx53]

Funny Euro run beyond Day 5...large noreaster with plenty of precipitation throughout the area (and assuming some wind/rough seas as well)...followed by a fujiwara and late developing second noreaster right behind it with snow showers over the region. Huge trough but no connection to the cold air so it would moderate rapidly.

That being said the GEFS and Euro in the long range are beginning to hint at some changes by the end of the month. These usually get pushed back a bit but I think we might be getting the first signs of a more blocky pattern by the beginning of December. We'll see.

Aleutian Ridge/-NAO block connection perhaps?

[MJO812]

Allan Huffman

12z ECMWF Ensembles show a very strong west-based -NAO block late in 11-15 day period. Cold pattern looking likely early December.

[Weathergun]

Allan Huffman

Can see some of those changes at day 10. The cut-off low next week, becoming part of west-based -NAO pattern, would be essential:

[MJO812]

[HailMan06]

Sleeting at my work nead Bedminster right now

Really? I just drove through Bedminster about an hour after your post and only encounterd rain.

[Isotherm]

2006 is on the analog list 3 times, that was a torch December, and 1973 was also a very warm December in the Northeast. 1966, 1968, 1963, 1981, and 2010 however were all colder than normal Decembers.

The Atlantic response is very important going forward into Dec; a strong Aleutian ridge might be sufficient to keep cold wx running along the northern tier, but that's not a good pattern for us. We need some blocking in the NATL, preferrably some sort of connection across the top of the globe, which would really induce the cross-polar flow and make things exciting for dec cold/snow wise.

[earthlight]

The Atlantic response is very important going forward into Dec; a strong Aleutian ridge might be sufficient to keep cold wx running along the northern tier, but that's not a good pattern for us. We need some blocking in the NATL, preferrably some sort of connection across the top of the globe, which would really induce the cross-polar flow and make things exciting for dec cold/snow wise.

Two weeks from now we will be in crunch time for sure. We should start getting some better signs as to whats going on in about a weeks time. We need to carefully watch some solar stuff as well as the response of the main features in the Pacific and Atlantic. The recent blocking episode was incredible and a great sign for the winter, and they can often repeat themselves (actually usually they do, especially when they're so prolific). I could have it my way...I would like to see signs of a return of ridging near Greenland, the NW Atlantic, and building near the Davis Straight by the first 7-10 days of December.

Often these pattern changes take a little while to roll forward. Take December 2010 just as an example, we had the big blocking build in during the first few weeks, but the actual storminess and onslaught of snow in the pattern didn't start until 12/20 (we missed a storm chance there) and then 12/26 and so on and so forth. So it will be interesting to see if the pattern starts to unfold a bit over the next few weeks.

Almost all medium to long range guidance has a monster positive anomaly at H5 over the Aleutians, which is a great sign considering what we know about the blocking. If it returns anything like the past few months -- we will be in business. I guess we'll see.

[Weathergun]

Very large storm on the 12z ECMWF, early next week. We would start seeing some rain and wind, well before the center nears us:

[FPizz]

Really? I just drove through Bedminster about an hour after your post and only encounterd rain.

it did it for about 10 minutes.

[Isotherm]

Two weeks from now we will be in crunch time for sure. We should start getting some better signs as to whats going on in about a weeks time. We need to carefully watch some solar stuff as well as the response of the main features in the Pacific and Atlantic. The recent blocking episode was incredible and a great sign for the winter, and they can often repeat themselves (actually usually they do, especially when they're so prolific). I could have it my way...I would like to see signs of a return of ridging near Greenland, the NW Atlantic, and building near the Davis Straight by the first 7-10 days of December.

Often these pattern changes take a little while to roll forward. Take December 2010 just as an example, we had the big blocking build in during the first few weeks, but the actual storminess and onslaught of snow in the pattern didn't start until 12/20 (we missed a storm chance there) and then 12/26 and so on and so forth. So it will be interesting to see if the pattern starts to unfold a bit over the next few weeks.

Almost all medium to long range guidance has a monster positive anomaly at H5 over the Aleutians, which is a great sign considering what we know about the blocking. If it returns anything like the past few months -- we will be in business. I guess we'll see.

Yeah I agree, I'll pretty much have my mind made up on this winter another week or so from now. Certainly there's no doubt we're looking improved (significantly) from last year's global atmospheric pattern. At least we've got rumors of blocking on model data - last year at this time we saw no end in sight with the Arctic vortex of doom. I've been on the fence thus far regarding NAO/AO regime this winter and as you noted the recent solar data isn't very encouraging in that respect. We do have the -QBO but with increased ap and flux values it may not be a big help. Pattern persistence is an important element as well, and that's one of the reasons why I'm waiting another week to make a call on this. If the major west based blocking shown on some guidance does in fact develop by early december, then look out, I think we're in for a good winter ahead. If this is all fantasy and we don't get the -NAO going in the next 10-14 days, we'll probably be looking at a meh December with our hopes pinned on mid/late winter.

[Storm At Sea]

This is the best ensemble agreement that I have see in quite some time...I'm really not sweating it out at this point...I think the tendency for a -NAO continues throughout the next 2 mon...However, if you look at winters following Octobers with significant -NAO (<-1 on average for the month) there appears to be correlation of more positive NAO averages month to month as the winter progresses.

Yeah I agree, I'll pretty much have my mind made up on this winter another week or so from now.

Certainly there's no doubt we're looking improved (significantly) from last year's global atmospheric pattern. At least we've got rumors of blocking on model data - last year at this time we saw no end in sight with the Arctic vortex of doom. I've been on the fence thus far regarding NAO/AO regime this winter and as you noted the recent solar data isn't very encouraging in that respect. We do have the -QBO but with increased ap and flux values it may not be a big help. Pattern persistence is an important element as well, and that's one of the reasons why I'm waiting another week to make a call on this. If the major west based blocking shown on some guidance does in fact develop by early december, then look out, I think we're in for a good winter ahead. If this is all fantasy and we don't get the -NAO going in the next 10-14 days, we'll probably be looking at a meh December with our hopes pinned on mid/late winter.

[earthlight]

This is the best ensemble agreement that I have see in quite some time...I'm really not sweating it out at this point...I think the tendency for a -NAO continues throughout the next 2 mon...However, if you look at winters following Octobers with significant -NAO (<-1 on average for the month) there appears to be correlation of more positive NAO averages month to month as the winter progresses.

Yeah almost all of the ensembles now are starting to show the NAO falling...I am a little more intrigued at exactly how it goes down, though. A -NAO is good but in order to kick things off you would want it to be more west based. The GEFS are beginning to hint at this in the long range. One other thing is that the Euro ensembles have been getting better each cycle that I've seen them in terms of a pattern that could eventually produce maybe 3-4 weeks from now or slightly longer than that.

Also interesting to see a huge positive anomaly/mid and upper level ridge over the Aleutians on the GEFS for several runs now ... they are really going to town with that feature. Despite the ULL sitting in the NE Pac to the southeast of that, the Aleutian ridge could help transport cold air into the northern 1/3.

[andyhb]

Yeah almost all of the ensembles now are starting to show the NAO falling...I am a little more intrigued at exactly how it goes down, though. A -NAO is good but in order to kick things off you would want it to be more west based. The GEFS are beginning to hint at this in the long range. One other thing is that the Euro ensembles have been getting better each cycle that I've seen them in terms of a pattern that could eventually produce maybe 3-4 weeks from now or slightly longer than that.

I'd certainly rather the pattern on the ensembles plays out for you rather than the one on the 00z GFS Op.

[earthlight]

I'd certainly rather the pattern on the ensembles plays out for you rather than the one on the 00z GFS Op.

The OP GFS isn't worth a look in the long range, let alone the medium range. But yeah, it's pretty bad. The ensembles offer a much better look into things at that range. Seeing the Euro ensembles improve each run the last day or two has been very encouraging.