NYC/PHL Jan 25-28 Potential Threat Part 2

[40/70 Benchmark]

It might be a tick or two warm at 850, but a strong low near ACY and moving into LI will bring a ton of warm air with it. That surface high is doing its best to try and hang colder air in. This solution would be exponentially better for many of it were a bit east, or dug even a little less when it nears the Gulf.

I think that is very likely.

[ORH_wxman]

Then why is it I still get over a 1' of snow, despite being further east.......strange.

Because you are much closer to the cold air source with the departing arctic high....so you can hang onto to snow longer than further SW in this setup. Always watch where the cold air source is.

[40/70 Benchmark]

Monday night's storm was a disaster track for us and we still started with 2" of snow and then major icing. We had little antecedent cold air compared to this weekend and the surface low tracked through Iowa. Case in point: cold air generally holds on longer than expected, and dynamics take over especially when you have some elevation and are NW of a strong low pressure.

Also, the ECM is much more amplified than other guidance, and each run has trended farther east. This was originally an inland cutter and now has trended to a benchmark coastal. The GFS and GGEM have both been trending east as well. What does this say to you?

This run is a little west of 12z.

[Kingwill]

If the Euro or any other Model is Showing a Driving Rainstorm Sun Night or Mon Morning maybe I will buy it but until than I am holding out Hope with the GFS and other Models Showing at least SOME Frozen precip and that High Finds a way to not slide too far East..It has been a very good winter for snow lovers in My neck of the woods and as someone else wrote Snow Begets Snow. Here is hoping it finds a way.. I like alot of others on here however would be pretty Bummed that in the Middle of Winter on the Heels of some near Record Breaking Temps a Boatload of Precip comes up the coast in the Form of a Deluge... Should be a interesting weekend following this thing..

[earthlight]

It just depends where the surface low tracks. I'm only worried about rain if it's west of me. Period.

You're kidding right?

[nzucker]

540m thickness line is right over NYC...very close to a wet snow bomb, and I believe it is if you subtract 1-2C from the ECM 850s to account for bias.

We'll see who verifies when we get there, but I'm guessing this is a snowy storm unless it gets west of us over the Apps.

[ORH_wxman]

Monday night's storm was a disaster track for us and we still started with 2" of snow and then major icing. We had little antecedent cold air compared to this weekend and the surface low tracked through Iowa. Case in point: cold air generally holds on longer than expected, and dynamics take over especially when you have some elevation and are NW of a strong low pressure.

Also, the ECM is much more amplified than other guidance, and each run has trended farther east. This was originally an inland cutter and now has trended to a benchmark coastal. The GFS and GGEM have both been trending east as well. What does this say to you?

ECM very well might be a bit too amped up, but I'm saying if that type of dynamic track verifies, do not expect much snow out of it. Maybe a bit on the front end and maybe a bit to end....but that will wrap in a lot of warm air...especially near the center of the low where the departing arctic high has less influence.

[40/70 Benchmark]

Because you are much closer to the cold air source with the departing arctic high....so you can hang onto to snow longer than further SW in this setup. Always watch where the cold air source is.

Thx.

[CoastalWx]

I think that is very likely.

It's not always where the low tracks, but the alignment of mid level features that allow warm maritime air to flood inland. Sure in this case the low tracks just east of NYC, but we have massive erly flow out ahead of it. Luckily for you, the antecedent cold lasts long enough and dynamics help fight off the warm intrusion for a front end dump. Like Will said..that low could throw a lot of rain further west..even with a low track in that position, esp down that way.

[NortheastPAWx]

you start as rain then flip to hvy snow.

Uggh, how much rain?

[nzucker]

You're kidding right?

You think a 975mb coastal south of Montauk is rain for someone at 400' in Westchester County? You're kidding me, right, John?

Also, don't you think this looks a little more amplified than all the other models? Doesn't this seem suspicious?

[CoastalWx]

540m thickness line is right over NYC...very close to a wet snow bomb, and I believe it is if you subtract 1-2C from the ECM 850s to account for bias.

We'll see who verifies when we get there, but I'm guessing this is a snowy storm unless it gets west of us over the Apps.

Because mid levels are cold. It's warm in the boundary layer.

[nzucker]

ECM very well might be a bit too amped up, but I'm saying if that type of dynamic track verifies, do not expect much snow out of it. Maybe a bit on the front end and maybe a bit to end....but that will wrap in a lot of warm air...especially near the center of the low where the departing arctic high has less influence.

The low is 975mb south of Montauk, that's like 150 miles from me LOL.

[earthlight]

540m thickness line is right over NYC...very close to a wet snow bomb, and I believe it is if you subtract 1-2C from the ECM 850s to account for bias.

Dude, what are you looking at...552 thicknesses are on Long Island at 114 hrs and the 546 Thickness is in Litchfield Co Connecticut. The 540 line is in Northern MA....this is during the main QPF.

[NittanyWx]

540m thickness line is right over NYC...very close to a wet snow bomb, and I believe it is if you subtract 1-2C from the ECM 850s to account for bias.

We'll see who verifies when we get there, but I'm guessing this is a snowy storm unless it gets west of us over the Apps.

The boundary layer will be warmed by screaming easterly winds. And what hour are you looking at exactly?

[TheTrials]

540m thickness line is right over NYC...very close to a wet snow bomb, and I believe it is if you subtract 1-2C from the ECM 850s to account for bias.

We'll see who verifies when we get there, but I'm guessing this is a snowy storm unless it gets west of us over the Apps.

your heights are about 550 at 108-114 hours when its pouring.

it only comes back when the storm is pulling away and basically over.

[GD0815]

the point is the storm could very well be snow in NYC, but not with the solution the Euro is depicting.

540m thickness line is right over NYC...very close to a wet snow bomb, and I believe it is if you subtract 1-2C from the ECM 850s to account for bias.

We'll see who verifies when we get there, but I'm guessing this is a snowy storm unless it gets west of us over the Apps.

[40/70 Benchmark]

The low is 975mb south of Montauk, that's like 150 miles from me LOL.

Man, you can be pig-headed.

[Neblizzard]

ECM very well might be a bit too amped up, but I'm saying if that type of dynamic track verifies, do not expect much snow out of it. Maybe a bit on the front end and maybe a bit to end....but that will wrap in a lot of warm air...especially near the center of the low where the departing arctic high has less influence.

Will, take the EURO and move it to the benchmark, wouldn't it still rain for NYC?

[LakeEffectKing]

540m thickness line is right over NYC...very close to a wet snow bomb, and I believe it is if you subtract 1-2C from the ECM 850s to account for bias.

We'll see who verifies when we get there, but I'm guessing this is a snowy storm unless it gets west of us over the Apps.

The entire coast has screaming easterly winds 12-24 hours before the LP comes around, not to mention the tropical feed it will originate from.....Euro verbatum....

[earthlight]

You think a 975mb coastal south of Montauk is rain for someone at 400' in Westchester County? You're kidding me, right, John?

Also, don't you think this looks a little more amplified than all the other models? Doesn't this seem suspicious?

Here's the text data for HPN at 114 hours.

That's 4.7 C at the surface, 3.2 C at 850..and 1.26" liquid...as rain. And 550 thicknesses.

WED 18Z 26-JAN 4.7 3.2 986 93 100 1.26 539 550

[TheTrials]

Here's the text data for HPN at 114 hours.

That's 4.7 C at the surface, 3.2 C at 850..and 1.26" liquid...as rain. And 550 thicknesses.

WED 18Z 26-JAN 4.7 3.2 986 93 100 1.26 539 550

well, to be fair, he is at 440 feet, so his surface temp is probably 4.5C

[nzucker]

Dude, what are you looking at...552 thicknesses are on Long Island at 114 hrs and the 546 Thickness is in Litchfield Co Connecticut. The 540 line is in Northern MA....this is during the main QPF.

At 120 hours the 540m line crashes near NYC with a 975mb low near Montauk...that's definitely changing over to snow.

The boundary layer will be warmed by screaming easterly winds.

That's where elevation and being outside the urban heat island, farther from the Atlantic comes into play.

Models are guidance. I generally go with a blend of them for my forecast, and that suggests a Nor'easter that's mostly snow, frankly. I am not going to take a warm-biased overamplified model verbatim at Day 5 considering the problems the ECM has had.

0z GFS ENS individual members are out...they are all out to sea, not a hit for NYC.

[GD0815]

we are discussing this solution, we know it is going to change, does that mean we sholdn't discuss it? n you can say this with every model run and every storm, what is the point

I hate to nip and tuck here;

but this is going to change tomorrow and Sunday; everyone needs to relax a little bit here.

[40/70 Benchmark]

Surface conditions depicted on the 0z ECMMF are eerily similar to the Dec 12, 1992 event...big retreating high northeast of Caribou, deepening low near the Chesapeake Bay...that was a terrible time of year for snow...water temps in the 50's, etc...yet slightly elevated areas such as Greenwood Lake, NJ (just NW of NYC) were buried under heavy snow..and we all know what happened in the Berkshires and 5 miles inland from Logan...

I got 21" from that, but it came on the backend....this one is a front-ender.

[ORH_wxman]

The low is 975mb south of Montauk, that's like 150 miles from me LOL.

You are being blinded by snow goggles here. The 850 low basically goes over your head...that is not a snow track. You have hours of ranging E/SE winds in the boundary layer as the low climbs the coast.

You don't get snow because a sfc low goes east of you. You have to look at all levels and also how the sfc low gets there....if it was out in the ocean and came due north into LI, that would be a lot more favorable...but this low comes from Delaware, tracks over S NJ and then over LI....that type of track gives you a lot of SE flow in the boundary layer.

[listarz]

Jeez, even I get it...Euro run tonight is a boatload of rain because of lack of blocking. will it verify? Maybe ...maybe not? Can we move on now?

[40/70 Benchmark]

At 120 hours the 540m line crashes near NYC with a 975mb low near Montauk...that's definitely changing over to snow.

That's where elevation and being outside the urban heat island, farther from the Atlantic comes into play.

Models are guidance. I generally go with a blend of them for my forecast, and that suggests a Nor'easter that's mostly snow, frankly. I am not going to take a warm-biased overamplified model verbatim at Day 5 considering the problems the ECM has had.

0z GFS ENS individual members are out...they are all out to sea, not a hit for NYC.

The mean was over the BM.

[earthlight]

At 120 hours the 540m line crashes near NYC with a 975mb low near Montauk...that's definitely changing over to snow.

Lol...dude, how can you just ignore the screaming southeast flow in the lower levels with the poorly positioned high pressure? Just to lay this to rest, HPN surface temp at 120 hours is still 4.1 C and your thickness is 542.

[CoastalWx]

You are being blinded by snow goggles here. The 850 low basically goes over your head...that is not a snow track. You have hours of ranging E/SE winds in the boundary layer as the low climbs the coast.

You don't get snow because a sfc low goes east of you. You have to look at all levels and also how the sfc low gets there....if it was out in the ocean and came due north into LI, that would be a lot more favorable...but this low comes from Delaware, tracks over S NJ and then over LI....that type of track gives you a lot of SE flow in the boundary layer.

Exactly.