Dec 9th Winter Threat

[CT Rain]

Yeah, this run isn't as good as 00z for the long range. 

 

Doesn't really matter - what a D10 op run shows is worth nothing more than a chuckle. 

[weathafella]

In think it's been apparent for days the pattern relaxes the week of 12/15. Hopefully it's back the week of 12/22.

[Ginx snewx]

Doesn't really matter - what a D10 op run shows is worth nothing more than a chuckle. 

this

[CoastalWx]

I thought this was a good run until day 9, but the euro at day 9 is many times out to lunch. You also can't have it in the teens and snow for days on end either. I wouldn't worry.

[Ginx snewx]

I thought this was a good run until day 9, but the euro at day 9 is many times out to lunch. You also can't have it in the teens and snow for days on end either. I wouldn't worry.

Great call by the way by you well in advance highlighting this period, certainly active and you were dead nut on about not worrying about the lack of precip way back in mid Nov. This is great despite PF and Tip calling it a POS, its gon snow, twice in a 4 day period, everything else is OK, not every storm is a 10 inch upslope or a coastal.

[scoob40]

Great call by the way by you well in advance highlighting this period, certainly active and you were dead nut on about not worrying about the lack of precip way back in mid Nov. This is great despite PF and Tip calling it a POS, its gon snow, twice in a 4 day period, everything else is OK, not every storm is a 10 inch upslope or a coastal.

An inch at best here for 12-6 overnight into 12-7 and 2'' at best on 12-9 before the change is the way this amateur sees it. NBD but encouraging.

[40/70 Benchmark]

I think this run's ugly myself...  

SWFE events are inherently ugly....how many prototypical winter events do you see occur with a "southwest flow" establishing itself in the mid levels? lol

 

It's a akin to winning the game on an error.....did the '86 Mets decline their rings?

Doesn't have to be pretty, just snow.

[powderfreak]

SWFE events are inherently ugly....how many prototypical winter events do you see occur with a "southwest flow" establishing itself in the mid levels? lol

 

It's a akin to winning the game on an error.....did the '86 Mets decline their rings?

Doesn't have to be pretty, just snow.

 

I like that analogy... winning the game on an error, but a win is a win.  More snow on the ground than prior to the event is always a win regardless of how it gets there.

[powderfreak]

Great call by the way by you well in advance highlighting this period, certainly active and you were dead nut on about not worrying about the lack of precip way back in mid Nov. This is great despite PF and Tip calling it a POS, its gon snow, twice in a 4 day period, everything else is OK, not every storm is a 10 inch upslope or a coastal.

 

lol, it still doesn't make it a pretty system.  It gets the job done though. 

[Typhoon Tip]

SWFE events are inherently ugly....how many prototypical winter events do you see occur with a "southwest flow" establishing itself in the mid levels? lol

 

It's a akin to winning the game on an error.....did the '86 Mets decline their rings?

Doesn't have to be pretty, just snow.

 

'Bout sums it up, yup ... 

 

Euro actually has more snow than the GFS, which is interesting...     Why that is interesting, I have no idea, or what it should even mean.

 

I think of this POS as 4" of bursted pants tent, followed by .2" of glazing (less S), followed by .45" of cold rain all the way to Orange Massachusetts, then a flash freeze.  4" turns into 2" of cement.   Probably I'll be wrong with that... but it's just the way it "looks" to me right now. 

 

I suppose though, like in 2007 we had a 10 or 12" snow from a front end reach-around, so stranger things have happened.  It will be a large cold high pressure leading the way...

[dryslot]

MEX guidance.

 

for NEWBIES:  1=1-2, 2=2-4, 4=4-6, 6=6-9, 8=8+

 

 

ORH/BED/BAF/BVY/BDL/CON/AUG/PWM/SFM:  4

BOS/EWB/PVD/BTV:  2

 

Some spots have a bit extra beyond the period.

 

Dryslot looks to be in today's jackpot.

Euro gave me a little luv on sat, Where the GFS is dry here on Saturday, The 12z Euro was better then 0z up here

[ctsnowstorm628]

Euro Ensembles look a hair warmer than the OP, with 0C 850 isotherm north of PSF to near BOS at 12z Monday.  Cold at the surface into northern CT however.

[It's Always Sunny]

This weenie board loses me sometimes...

 

I feel like I understand what a SWFE is based on everyone's posts, but can someone who knows what they're talking about give me a more official definition? I get that it's SW flow aloft with some nice moist, warm air from the gulf advecting NE enhancing isentropic lift. Precip type also appears to be more latitudinal dependent. Am I missing anything else?

 

Since I'm on the topic of asking questions, can someone also give me the American Wx definition of a so called "cutter"? From my understanding it is something that swoops in from the Great Lakes, swipes us shortly with w/e precip it has, then continues to move NE/ENE. Am I right on that? To me they are similar to that of an Alberta clipper, although not exactly the same thing due to the place of origination.

 

Thanks in advance.

[HoarfrostHubb]

I think most people in the New England threads refer to a cutter as a system where the low heads up to the north or even northwest and the center is in the eastern Great Lakes, flooding us with warmth and rain.

[ORH_wxman]

This weenie board loses me sometimes...

 

I feel like I understand what a SWFE is based on everyone's posts, but can someone who knows what they're talking about give me a more official definition? I get that it's SW flow aloft with some nice moist, warm air from the gulf advecting NE enhancing isentropic lift. Precip type also appears to be more latitudinal dependent. Am I missing anything else?

 

Since I'm on the topic of asking questions, can someone also give me the American Wx definition of a so called "cutter"? From my understanding it is something that swoops in from the Great Lakes, swipes us shortly with w/e precip it has, then continues to move NE/ENE. Am I right on that? To me they are similar to that of an Alberta clipper, although not exactly the same thing due to the place of origination.

 

Thanks in advance.

 

 

You are correct with the SWFE definition...they are defined (as per Ekster's and I's discussions years ago) by deep layer SW flow from the mid-levels to the upper levels running into a cold air dome that gives us an isentropic lift winter precip event...often transitioning to sleet or freezing rain when the mid-levels warm above 0C (though sometimes we'll stay all snow in these setups).

 

A lakes cutter is a storm that "cuts" west of us from the south or southwest up through the lakes...usually we torch and get rain from these.

[ADKweather27]

The part in front of the mirror... heh...  

 

No it's the whole vibe of the thing, where get smacked in the face with deep cold and the pattern et el blithely takes lows west of you.  Cutter-freeze pattern, that we just get kinda sorta lucky for happening to have a lead-side polar high;  otherwise, this is a big POS, objectively. 

 

Then, the extended retros the EPO ridging, flattens the flow, retreats continental cold into higher Canada, gets us above 0C at 850.   As Scott would say, pull the shades and ignore he weather until further notice on this run.   ...that is, after the POS early next week. 

 

Buuuut, that's just my take.  Maybe this is what folks really want, I dunno.  

agree 100%

[Damage In Tolland]

Wouldn't this be exactly opposite of what he's saying..a stronger more wound up system would flood the warmth in quicker..and a weaker solution actually helps hold the cold in.? right?

 

 

Matt Noyes ‏@MattNoyesNECN5m

Sun night/Mon storm is weak, meaning unlikely to see strong NE wind to hold cold, meaning coastal plain to rain quickly

[Randy4Confluence]

Love overrunny nose events. Dont have to worry about storms going ots. Snow to rain followed up with an arctic blast is cool too because the cold rain that freezes up the snowpack and so we have snow piles becoming part of the landscape for days and days. I'LL take a 2/14/07 Storm anytime. Maybe we can get some ice blocks in parking lots too. Yummy!

[powderfreak]

Wouldn't this be exactly opposite of what he's saying..a stronger more wound up system would flood the warmth in quicker..and a weaker solution actually helps hold the cold in.? right?

Matt Noyes ‏@MattNoyesNECN5m

Sun night/Mon storm is weak, meaning unlikely to see strong NE wind to hold cold, meaning coastal plain to rain quickly

Think about how the surface winds work around a low...a stronger secondary surface low near the SE coast would cause stronger NE winds on the north and northwest side of that secondary (aka holding the cold in). Winds aloft will be pounding warmth into the area regardless, but a strong secondary would certainly help hold the low level cold better than a weak one.

[Damage In Tolland]

Think about how the surface winds work around a low...a stronger secondary surface low near the SE coast would cause stronger NE winds on the north and northwest side of that secondary (aka holding the cold in). Winds aloft will be pounding warmth into the area regardless, but a strong secondary would certainly help hold the low level cold better than a weak one.

Nah..The Euro and GGEm both came in colder for the coast with a weaker, strung out low

[Typhoon Tip]

Well ... inventing expressions to describe events is fine.    

 

SWFE, or cutter that has a big dome of cold high pressure to contend with... or just a mid level WAA advent with cold in place, it's all good.  

 

But, the basic pattern is still a storm track that's west.  The core of the westerlies is going to be west of New England until after that event early next week.  Since that will "technically" be a transitional period, there may also be some typical uncertainty associated with that.  

 

As I was telling Scott yesterday, though the mass of the various GEF members was negative re the NAO, the fact that they were getting there "mop-ended", really means there is just as much uncertainty as to whether a negative regime is real.  Well, sure enough ... the runs cam out last night and all that mop-ended spread has wound up on the plus side -- so case in point.   Anyway, that is definitely related to why the storm track is situated west for the time being. 

 

It will be interesting later next week where things go from there..

[powderfreak]

Nah..The Euro and GGEm both came in colder for the coast with a weaker, strung out low

Next time you are looking for a strong secondary low to hold the cold should we say nahhh, you want it weak?

Synoptically you want a strong secondary, that's what you always want in these situations, it's why you always look for that redeveloping low south of SNE. The stronger the low to your SE, the more you hold the cold.

[Ginx snewx]

Next time you are looking for a strong secondary low to hold the cold should we say nahhh, you want it weak?

Synoptically you want a strong secondary, that's what you always want in these situations, it's why you always look for that redeveloping low south of SNE. The stronger the low to your SE, the more you hold the cold.

What Kev is saying is right, if a storm in which the primary moves west of us the weaker it is, the more time the scouring process takes place.Noyes make no sense in this scenario. a stronger storm would flood everyone with marine air.

[Damage In Tolland]

What Kev is saying is right, if a storm in which the primary moves west of us the weaker it is the more time the scouring process takes place.Noyes make no sense in this scenario. a stronger storm would flood everyone with marine air.

Yeah...unsure what direction he's coming from

[Ginx snewx]

Yeah...unsure what direction he's coming from

If he was thinking a strong secondary would take over( Miller B )then his post makes sense but that is not the scenario. this has been a SWFE with a weak secondary on every model run I can recall.

[ORH_wxman]

You can argue it both ways...if the primary is weaker and we have a strung out secondary well south of SNE where the CAD high is the dominating influence, then that is pretty cold...but if the primary is stronger and the result is a weaker secondary, then you'd be warmer overall as the ageostrophic component would turn more easterly. If the primary were to redevelop much faster into a strong secondary, then you'd also be colder.

 

You need context when describing both the primary and secondary lows.

[Tropopause_Fold]

18z gfs...just at a quick glance...holds more promise, imo, for the interior for a prolonged icing situation. 

[Damage In Tolland]

You can argue it both ways...if the primary is weaker and we have a strung out secondary well south of SNE where the CAD high is the dominating influence, then that is pretty cold...but if the primary is stronger and the result is a weaker secondary, then you'd be warmer overall as the ageostrophic component would turn more easterly. If the primary were to redevelop much faster into a strong secondary, then you'd also be colder.

You need context when describing both the primary and secondary lows.

Yeah upon reflection it seems Freak was thinking of a strong coastal like Dec 92 when you flood the cp with warmth. In a situation like this , if you're on the coast and want frozen you want a weaker low allowing n drain

[SnowMan]

18z gfs...just at a quick glance...holds more promise, imo, for the interior for a prolonged icing situation. 

This is great news...hopefully it comes to fruition

[jamesnichols1989]

That polar vortex up north of the Canadian/US border in the Canadian Prairies is the killer in this overall synoptic setup.  It is too far west to support a colder more out to sea, or eastern solution therefore the primary low cuts through the lakes with a weak secondary component.  This is nothing worse than a 3" snow followed by sleet, freezing rain and plain rain.