12/7-12/8 Potential Event Discussion Part II

[earthlight]

Models have trended warmer as a result of more amplification on the east coast, lesser influence from the first shortwave to our north, and a faster movement of the shortwave in question to our south and east. With the storm still 51 hours away, weenies await a potential 1 degree change in temperature that could bring them 10 more minutes of snow.

In all seriousness, looks like a flip to snow for maybe an hour or two..especially west of the city..with the potential for a slushy inch or two. In higher elevations, or snywx land, a few inches of snow looks likely. Over the city and east, flakes should still fly..but no accumulation is expected.

Here's the NAM at 51 hrs. Let's get discussing, boys.

[TheTrials]

Tough to go aganst the trend right now. NAM probably still too far east which is why it still give a little bit of hope at the end. The euro is further west and even though it has been behind the 8 ball its hard to ignore it under 60 hours. UKMET has been very consistent with its handling the system and its matching the EURO now. Combine the trend with a putrid antecedent airmass and a fragile synoptic setup and I think the best anyone in the immediate nyc metro area sees is some mangled flakes at the end.

Northwest Jersey, mid-hudson valley into PA up to Kingston probably jackpots here.

[TheTrials]

Upton's take.

AS FAR AS P-TYPE IS CONCERNED...EXPECT ALL RAIN ACROSS NYC...LONG

ISLAND AND MUCH OF SOUTHERN CONNECTICUT. SOME FLAKES MAY MIX IN SOME

RAIN AS THE STORM COMES TO AN END ACROSS FAIRFIELD CT...AND PORTIONS

OF NORTHEAST NJ. ACROSS THE HIGHER ELEVATIONS OF NJ...AND THE LOWER

HUDSON VALLEY...THERE COULD BE A PERIOD OF LIGHT SNOW...WITH SOME

MINOR ACCUMULATIONS EXPECTED. DONT HAVE ENOUGH CONFIDENCE AT THIS

TIME TO GIVE AMOUNTS WITH WIDE VARIABILITY IN GUIDANCE OUTPUT.

[MJO812]

I really thought we had a chance with this storm because of the negative epo, the pv and the pna. I guess the nao and ao are more important in the east to get a nice size snowstorm than the pna and epo.There is still some time for a shift east but we are running out of time.

[Sundog]

We went from no storm, to snowstorm, to too close in 24 hours. I'm not saying that it WILL move east, but we can still see some favorable changes with the lead time we still have.

[earthlight]

I really thought we had a chance with this storm because of the negative epo, the pv and the pna. I guess the nao and ao are more important in the east to get a nice size snowstorm than the pna and epo.There is still some time for a shift east but we are running out of time.

This is why I kept beating into the ground the point that this storm was highly unlikely to begin with...and that even a slight change in the upper air pattern would screw us because the surrounding pattern is terrible.

Normally we have some wiggle room but in this situation we don't. And that was the point myself and a few others were trying to drive home a few days ago.

[TheTrials]

This is why I kept beating into the ground the point that this storm was highly unlikely to begin with...and that even a slight change in the upper air pattern would screw us because the surrounding pattern is terrible.

Normally we have some wiggle room but in this situation we don't. And that was the point myself and a few others were trying to drive home a few days ago.

Relying on a PV to guide your vort is an almost sure way to fail. I never want to see any PV's in Canada when talking about suRface lows coming up the coast.

[Weathergun]

I really thought we had a chance with this storm because of the negative epo, the pv and the pna. I guess the nao and ao are more important in the east to get a nice size snowstorm than the pna and epo.There is still some time for a shift east but we are running out of time.

While it's still possible to get an event with it, the EPO/PNA ridge is not really where want it, for a snowstorm, IMO. The core of the ridge is out in the Pacific, with just some extension of heights into Alaska and NW Canada:

[Edge Weather]

John,

I think we understood your point, but even with all of that, there is still a very real possibility of significant accumulations throughout Northern New Jersey. Let's wait and see.

This is why I kept beating into the ground the point that this storm was highly unlikely to begin with...and that even a slight change in the upper air pattern would screw us because the surrounding pattern is terrible.

Normally we have some wiggle room but in this situation we don't. And that was the point myself and a few others were trying to drive home a few days ago.

[TheTrials]

While it's still possible to get an event with it, the EPO/PNA ridge is not really where want it, for a snowstorm, IMO. The core of the ridge is out in the Pacific, with just some extension of heights into Alaska and NW Canada:

Add in the craptastic airmass in front of the storm and its a big goose egg for 99.9% of nyc metro.

Snywx should still do ok, but even he faces an uphill battle in the beginning.

[earthlight]

John,

I think we understood your point, but even with all of that, there is still a very real possibility of significant accumulations throughout Northern New Jersey. Let's wait and see.

Sure. But I think most of that will occur over the far interior or areas with elevation.

Don't get me wrong, I'll be more than stoked to see some snow. But as far as anything worthwhile..we aren't there yet.

[earthlight]

Add in the craptastic airmass in front of the storm and its a big goose egg for 99.9% of nyc metro.

Snywx should still do ok, but even he faces an uphill battle in the beginning.

I think you're being a little hard on this storm. It's def. not going to be a moderate event or anything, but I think everybody will be happy to see some snow.

If you're only looking for the moderate or greater events than yes..this one doesn't have a chance and you should probably sleep until new years lol.

[Weathergun]

Add in the craptastic airmass in front of the storm and its a big goose egg for 99.9% of nyc metro.

Snywx should still do ok, but even he faces an uphill battle in the beginning.

If we also had a Greenland/Davis Straight Block, we would do much better with that ridge in place. But just have that ridge placed there alone, doesn't do much for us.

[TheTrials]

I think you're being a little hard on this storm. It's def. not going to be a moderate event or anything, but I think everybody will be happy to see some snow.

If you're only looking for the moderate or greater events than yes..this one doesn't have a chance and you should probably sleep until new years lol.

I think the populated areas are gonna have to squint into the lights for about ten minutes at the end of the storm to see wet mangled flakes, including your area.

NW jersey, orange county on north, no doubt, they see some flakes, probably accumulation at the end.

[TheTrials]

If we also had a Greenland/Davis Straight Block, we would do much better with that ridge in place. But just have that ridge placed there alone, doesn't do much for us.

the block would guide the storm and prevent the big NW trend we have been seeing, which probably isn't done. Euro is literally right down the middle of LI with its surface low and takes all the precip away before anyone save far N&W can see a flake.

This thing can still come up and over NYC if it wanted to.

[bluewave]

We'll have to watch for the potential of perhaps a slight shift west on today's runs with

the model trend of weakening the lead wave. With the trough going negative tilt and

a great coupled jet, we could also see a nice burst winds behind it mix down in the CAA.

[TheTrials]

We'll have to watch for the potential of perhaps a slight shift west on today's runs with

the model trend of weakening the lead wave. With the trough going negative tilt and

a great coupled jet, we could also see a nice burst winds behind it mix down in the CAA.

might as well just bring the thing over PA, warm sector us and give us a nice bow echo around 3am because that would at least make things interesting around here. What a terribly boring and mundance stretch of weather, although drying out hasn't been a bad thing at all.

[jm1220]

The best shot for real snow to me looks to be roughly along or just west of the I-81 corridor and then up through the Berkshires, Green/White mountains, etc. East of the Delaware River to maybe I-287 or so gets a brief swipe of snow at the tail end, maybe some brief slushy accumulation. East of there it's just plain rain. This should be a textbook example of why not to get excited about a storm like this in a +NAO pattern and zero blocking.

[ag3]

^{New srefs have .50"-.75" of precip for tomorrow night's storm.}

^{Unfortunately, srefs are warm and have very little snow for NYC and the immediate areas:}

[bluewave]

might as well just bring the thing over PA, warm sector us and give us a nice bow echo around 3am because that would at least make things interesting around here. What a terribly boring and mundance stretch of weather, although drying out hasn't been a bad thing at all.

The dynamics and moisture looks great with this storm though no lucky block like the end of October.

[jm1220]

^{New srefs have .50"-.75" of precip for tomorrow night's storm.}

^{Unfortunately, srefs are warm and have very little snow for NYC and the immediate areas:}

The fact that it's getting stronger (and thus more precip), however, is what's driving this close to the coast and holding warm air with it. We could have had this shunted SE anyway if we had more resistance via a 50-50 low or blocking of some sort to the north. Instead, in a progressive pattern, it can track wherever it pleases.

Until that changes in this Nina regime, I personally expect the same kind of pattern. The SE ridge will be very resistant to move without resistance in Canada. A PV over central Canada won't do it either.

[ag3]

Heights are a little lower on 12z NAM, when compared to 6z NAM so far through hour 21.

Not sure if it'll make a difference in the end.

[Stormlover74]

Another threat I recall was around 12/19/1997. Initially 3 to 5 days out it was looking like a decent snow event for the area but as we got closer it kept getting warmer and warmer to the point where I think well N&W got a period of freezing drizzle out of it. Otherwise it just a rain event. That was the closest we got to tracking anything of significance snow wise until March as everything in Jan/Feb was windswept heavy rain with temps in the 40s and 50s. Oh well in a nino that strong shouldn't have been a shock I guess.

[forkyfork]

the nam is even more amplified and faster... we might get some flooding from this

[ag3]

the nam is even more amplified and faster... we might get some flooding from this

Yeah. Heights are lower still at hour 27, but its faster and more amplified.

850 temps are a little colder though, when compared to 6z. But not much.

[ag3]

994 LOW just SE of Montauk at hour 42. Temps finally responding but its the tail end of storm.

[ag3]

Temp profiles are close at hour 45.

After hour 45, about .15" falls over NYC.

NYC has a 3 hour window of wet snow tops, on the NAM.

[rgwp96]

Temp profiles are close at hour 45.

After hour 45, about .25" falls over NYC.

NYC has a 3 hour window of wet snow, tops on the NAM.

kmmu all snow at 45 hrs ,

[ag3]

kmmu all snow at 45 hrs ,

The storm is over for Jersey at that hour. Under .10" falls after hour 45.

[jjvesnow]

kmmu all snow at 45 hrs ,

What about 42 hrs?