Thanksgiving Week Nor'easter Discussion

[IsentropicLift]

There's nothing to slow down the pattern and force the trough to dig and grab the southern stream disturbance. There's a ridge in the West, but the flow is flatter to the east and it's a neutral NAO at best. This allows the northern stream disturbance to zoom east and flatten the southern stream disturbance, causing everything to shear out to sea. Not saying that's going to happen but it certainly could happen.

Yes it's possible and indicative of the progressive pattern we've been seeing. I suspect it will be awhile before this is resolved.

[forkyfork]

the atlantic is flat out awful for east coast storms

[WeatherFox]

It looks borderline in the NW burbs. I wonder if this ends up being our sacrificial lamb that breaks the pattern.

[WeatherFox]

Let's hope it does. I actually see these early nor'easter rain storms as a positive indicator of a snowy winter. (Persistence forecasting).

[alwaysready126]

Let's hope it does. I actually see these early nor'easter rain storms as a positive indicator of a snowy winter.

The problem is that nor'easters only show up on CPU monitors and not on our front steps.

[WeatherFox]

Will see..still days away!

[MJO812]

Will see..still days away!

Exactly

[SnoSki14]

the atlantic is flat out awful for east coast storms

Yea I get it, u hate snow and cold.

[Brian5671]

Yea I get it, u hate snow and cold.

His routine is beyond old.

[forkyfork]

Yea I get it, u hate snow and cold.

can you actually refute my point? the anomalies are opposite what you want to see for an east coast storm, at least over the western atlantic

[jm1220]

Yea I get it, u hate snow and cold.

 

That has nothing to do with it. When you look at the charts at the time frame we have the potential storm, there's a flat, fast flow to the east across eastern Canada into the Atlantic (+NAO). That's not conducive to a trough digging and a phase. It could happen still, but I would argue that there's also a large possibility that the sheared out models are right. We want for there to be more ridging near Greenland so that at least it forces the northern stream to slow down and dig the trough more.

[Heisy]

The pattern is fine for phasing as long as that northern stream doesn't out run the southern stream.

 

Yeah, but then you get a rainstorm because there's no reinforcing cold shot, this is a lose lose storm, but its November, and good to see potential storms this early. 

[IsentropicLift]

Yeah, but then you get a rainstorm because there's no reinforcing cold shot, this is a lose lose storm, but its November, and good to see potential storms this early. 

I would be very happy with a soaking rainstorm. In fact I think I'd rather have that than snow right now.

[Isotherm]

The Atlantic is currently unfavorable for an east coast snow storm, I agree with that. Without a block of 50/50 low it's difficult to hold the cold along the coast especially this time of year. A strong low would easily raise heights and turn the coast quickly to rain. It's the type of pattern that either favors out to sea or snow interior/rain coast right now.

 

Pacific however will get progressively more favorable into early December.

[SnoSki14]

That has nothing to do with it. When you look at the charts at the time frame we have the potential storm, there's a flat, fast flow to the east across eastern Canada into the Atlantic (+NAO). That's not conducive to a trough digging and a phase. It could happen still, but I would argue that there's also a large possibility that the sheared out models are right. We want for there to be more ridging near Greenland so that at least it forces the northern stream to slow down and dig the trough more.

I was generally referring to that poster's previous negative responses or statements although they do have a point in this case. I know the Atlantic isn't favorable enough for a coastal storm but we aren't in a zonal flow. There will be a trough over us, more than we would want because it kicks the southern stream system too far to the east. I agree about the fast flow because these troughs move in and out fairly quickly.

The worst case scenario for myself this winter is cold to very cold but dry. I really hope the dry pattern changes soon or that's what we will have to deal with. Bitterly cold for days without any snow/snow threats is just painful. I'll take warm and dry any day over that scenario.

[JSantanaNYC]

Let's forget about snow..and let's get a good soaking rain day we really need one.

[IsentropicLift]

Looks like the snow showers on Tuesday morning are legit.

 

That is one potent piece of energy ejecting from the southern stream as far as next week is concerned. Widespread 2-3" of rain plus down south.

[IntenseBlizzard2014]

The Atlantic is currently unfavorable for an east coast snow storm, I agree with that. Without a block of 50/50 low it's difficult to hold the cold along the coast especially this time of year. A strong low would easily raise heights and turn the coast quickly to rain. It's the type of pattern that either favors out to sea or snow interior/rain coast right now.

 

Pacific however will get progressively more favorable into early December.

 

This looks like the kind of winter that even a little blocking over the Western Atlantic will do wonders. 

[IsentropicLift]

I'm at a loss, this is beyond my amateur level of understanding.

 

You have a potent negatively tilted trough over the deep south with good height rises up the coast and yet you have a strung out slop instead of one consolidated low.

[WE GOT HIM]

Closer to the coast this run for some showers but looks to be going ots again

[IsentropicLift]

Hour 177 it's killing off the first low and we have a sub 1000mb low just off the Carolina coast. Then slides east. To me this run is an improvement over 12z.

[supermeh]

You need the ridge out west to be better and provide the northern stream to dig further south and west to get phasing of some sort with the southern stream. There is no interaction between the vorts and as a result there is a jumbled mess.

[alwaysready126]

I'm at a loss, this is beyond my amateur level of understanding.

 

You have a potent negatively tilted trough over the deep south with good height rises up the coast and yet you have a strung out slop instead of one consolidated low.

You must take climatology into consideration.  It snows more than 4 inches in November only once every 25 years, on average from Connecticut to Philadelphia to DC.  Though, I do understand what you mean about a disorganized mess.  To that end it doesn't make sense to me either.  It's probably because the CPU's aren't handling the Pacific.

[SnoSki14]

You need the ridge out west to be better and provide the northern stream to dig further south and west to get phasing of some sort with the southern stream. There is no interaction between the vorts and as a result there is a jumbled mess.

 

That's one way to offset the lack of blocking is by getting more ridging out west. It's a potent southern stream system that can't be written off at this range. A lack of blocking doesn't mean we can't get a storm up here, but the timing as of now looks a little bit off. 

[rgwp96]

Hour 177 it's killing off the first low and we have a sub 1000mb low just off the Carolina coast. Then slides east. To me this run is an improvement over 12z.

compare the 500 mb maps from last night to todays runs and u will get your answer

[Kaner587]

This is a very convoluted upper air set-up as advertised. There are a bunch of northern stream vorts dropping down from the beautiful PNA ridge and we are still 120-144hrs out from the storm evolution. Odds are against frozen, I think we all know that. This progressive pattern and the way that ULL runs into the west coast flattening out our ridge really moves things along way too quickly for any type of major storm. If that ridge doesn't flatten out so quickly the southern stream vort can sort of meander around waiting for some northern stream energy to drop in. That is where blocking plays such a huge role and why this is so unlikely to produce anything significantly frozen; Without the blocking, the southern stream vort is forced eastward, so we end up with a strung out low too far east for any major precip. On the other hand, if that ridge were slower to dampen out, and the northern stream energy dropped in too far west, well we all know what the solution would be there. Which leads me to my final point about the fact that the odds are even against there being a major precip maker in our area at the moment because of the overwhelmingly progressive pattern (albeit for the most part unseasonably cold). Until we can slow things down I wouldn't expect significant frozen events, and even the warmer storms may be to progressive to even make it up the coast. 

 

IF we can get a sustained PNA ridge and these pacific storms cutting off in the sw, then it is possible that under ideal conditions one of these miller A's can run up the coast with a solid HP in place, without any major northern stream interaction. It doesn't look like this is the case for the t-giving threat for the reasons mentioned above.

[supermeh]

That's one way to offset the lack of blocking is by getting more ridging out west. It's a potent southern stream system that can't be written off at this range. A lack of blocking doesn't mean we can't get a storm up here, but the timing as of now looks a little bit off. 

The whole key is the northern energy being able to dig far enough south and west to interact with the southern stream and bring the system up the coast. Hard to believe in the progressive pattern we are in. Hopefully we get enough ridging out west to allow this.

[Kaner587]

The whole key is the northern energy being able to dig far enough south and west to interact with the southern stream and bring the system up the coast. Hard to believe in the progressive pattern we are in. Hopefully we get enough ridging out west to allow this.

Thats true. But if you look at the evolution of this storm at 500MB, what is clear is the dampening of our west coast ridge ends up acting as a kicker and preventing any meaningful interaction with the northern and southern streams. We would need absolute perfect timing (ie thread the needle) for any major interaction IMO

[NorthShoreWx]

The Atlantic is currently unfavorable for an east coast snow storm, I agree with that. Without a block of 50/50 low it's difficult to hold the cold along the coast especially this time of year. A strong low would easily raise heights and turn the coast quickly to rain. It's the type of pattern that either favors out to sea or snow interior/rain coast right now.

 

 

 

Sounds kinda November-like

[Kaner587]

We only get about 60 hrs of a meaningful west coast ridge before things breakdown and reload. We're going to need much longer than 60hrs to get a storm in here and make up for the lack of blocking. This pattern would be great if there was a mechanism to slow things down on our end.