December 9, 2017 - Storm Discussion (Breaking the seal on the season for many)

[CoastalWx]

It dries out the column a bit by 00z though. 

[OSUmetstud]

Reg was delayed for 45 minutes per a CMC email. 

[OceanStWx]

11 hours ago, ORH_wxman said:

It's too bad the baroclinic zone is barely escaping east because that is a sweet northern stream....not giving up on it yet, but the southern vort max dragging its heels isn't good.

I think you're onto something there. 

At 00z there was negligible difference between the Euro and GFS, and they were modeling the features out west fairly well. That considered, it should have been close to the Euro and not much different than its prior runs. But like you say, the northern stream outran the southern, and when it finally curled up it was too far east to do any damage.

 

[weathafella]

1 minute ago, dryslot said:

This 12z GFS run is better then 06z was but still has work to do.

It’s ok for a measurable snow for all off the cape.

[weathafella]

Solid 2-4+ for many.

[CoastalWx]

Just now, weathafella said:

Solid 2-4+ for many.

Pretty much. Tries for a little reach around after 6z as the system wraps up.

[dryslot]

Just now, weathafella said:

Solid 2-4+ for many.

Will get most on the board for snows now.

[Damage In Tolland]

2 minutes ago, weathafella said:

Kevin may make some eat their words...

Nah we don’t roll like that . I’ll be happy with a snowy weekend and the first foundation for a deep pack 

[40/70 Benchmark]

4 minutes ago, weathafella said:

Kevin may make some eat their words...

There were several others that remained leery of this making a come back...not rocket science with the look of that trough.

[CoastalWx]

For those QPF huggers...there was a nice mid level RH signal well west even into western CT. 

[OceanStWx]

1 minute ago, CoastalWx said:

Pretty much. Tries for a little reach around after 6z as the system wraps up.

I think our 495 crowd won't hate that run. They get all the benefits of powderfreak deformation magic without the magic happening over the picnic tables.

[WxBlue]

5 minutes ago, dryslot said:

This 12z GFS run is better then 06z was but still has work to do.

Being close to the coast in Dover, I honestly would take this run and pray changes from here on is nothing dramatic. But that's often not the case inside 72 hours with winter weather forecasting.

[weathafella]

Delivering 3 days after the deck chairs were drastically rearranged is an excellent sign presuming it happens.

[USCAPEWEATHERAF]

The 12z GFS looks to phase the two jet streams for our weekend storm

[dryslot]

6 minutes ago, WxBlue said:

Being close to the coast in Dover, I honestly would take this run and pray changes from here on is nothing dramatic. But that's often not the case inside 72 hours with winter weather forecasting.

 It wouldn't take much to make this one even more favorable if you got it to get captured sooner and tugged NW.

[CoastalWx]

2 minutes ago, OceanStWx said:

I think our 495 crowd won't hate that run. They get all the benefits of powderfreak deformation magic without the magic happening over the picnic tables.

Even further west it seemed to me as well.

[weathafella]

Just texted my wife:

 

“First Snow now looks likely Saturday afternoon and night.  

Of course you had weeks notice of a change in the weather pattern.”

[CoastalWx]

Bit of a coastal front in SE MA too.

[OceanStWx]

1 minute ago, CoastalWx said:

Even further west it seemed to me as well.

Yeah, I just didn't have a great highway approximation in mind.

One thing we'll have to be careful of, especially farther north, is that it's so cold aloft that some of the best lift may be too far above the DGZ.

[RUNNAWAYICEBERG]

Have to like where this is trending. Need consistency now with 12z euro and 0z to keep the trend coming. Bend back the mid level fronto some more and we plow across the state while  shovels scrape driveways. 

[CarverWX]

2 minutes ago, CoastalWx said:

Bit of a coastal front in SE MA too.

Hopefully this doesn't come ripping thru and change the snow to a 33 rain.

[CoastalWx]

1 minute ago, OceanStWx said:

Yeah, I just didn't have a great highway approximation in mind.

One thing we'll have to be careful of, especially farther north, is that it's so cold aloft that some of the best lift may be too far above the DGZ.

Nice little event. 

[WintersComing]

3 minutes ago, CoastalWx said:

Even further west it seemed to me as well.

Pretty nice lift going on in CT and MA

[dryslot]

2 minutes ago, OceanStWx said:

Yeah, I just didn't have a great highway approximation in mind.

One thing we'll have to be careful of, especially farther north, is that it's so cold aloft that some of the best lift may be too far above the DGZ.

Awesome..............

[dendrite]

1 minute ago, dryslot said:

Awesome..............

It’ll just be a manlier snow. 

[WxBlue]

8 minutes ago, dryslot said:

 It wouldn't take much to make this one even more favorable if you got it to get captured sooner and tugged NW.

Would be good for both of us! Just hope it doesn't overdo the correction. I think you should be safe pending a rather epic shift NW, though.

[OceanStWx]

2 hours ago, Typhoon Tip said:

Certainly possible ...  Oceanwx has been hitting the RAOBs argument over the last several pages - I suggest anyone that is curious go back and read his insights there and then employ the usual channels for furthering research.  

Thing is, I wonder if the initialization matrix of data has some sort of normalization to ferret out spurious data... For those in the know, obviously you know that the best tool in the game for that sort of smoothing is the ECMWF'  ... but, (may Ocean' knows? ) you'd think that all of them have at least some sort of checks and balances.  And, if so .. how far does that go?

It's amazingly complex... There could be a data point that is not ferreted out because it is unrecognizable to either machine or man, but is total bullchit, and is totally the whole cause for an errant solution.   You wouldn't know - 

All models basically handle spurious (maybe less spurious, more poorly modeled?) data the same way. The analysis starts running, observations (think raobs, satellite, etc) come in, the analysis is corrected in the direction of observations, then the analysis is allowed to continue. This is why upper air data can be so important for getting a sense of the true strength of features.

The difference becomes in how the models handle that observational assimilation. All models can handle the 3D stuff (the atmosphere is 3D after all), but the Euro is king for a reason. The 4th dimension is time. The Euro can place the observations at the correct time anywhere in the assimilation window. The GFS for instance has to assume that all observations happen at a specific time, whether that's the beginning, middle, or end of the window. If the window is say 6 hours long, that could mean very large errors are introduced right off the bat. The sacrifice is shorten the assimilation window (less obs). So the Euro can have a longer window (more obs), and correctly place those obs in time.

Now back to waiting on the reggie.

[RUNNAWAYICEBERG]

14 minutes ago, USCAPEWEATHERAF said:

The 12z GFS looks to phase the two jet streams for our weekend storm

A little more and it can capture the southern stream. Unfortunately that means your wet...and not the middle of night dream kind. 

[OceanStWx]

6 minutes ago, dendrite said:

It’ll just be a manlier snow. 

Some 8:1 baking power.

[dryslot]

Just now, WxBlue said:

Would be good for both of us! Just hope it doesn't overdo the correction. I think you should be safe pending a rather epic shift NW, though.

Yes, That low would need to be a huge shift NW like over DE Maine, Right now,  Itss tracking to the east of Novie now before it gets tugged, If it tracked over NS or in the GOM it would still be good.