Re: Long Range Thread 19.0

[heehaw453]

Regarding weekend threat
Amazing at 130 hours I feel this confident on the storm. I'll continue to keep an eye on it, but here's my thoughts.  
Let it prove me wrong!  Would love that.

High confidence in marginal antecedent air mass for our area.
High confidence this storm is going to move in the Atlantic and not inland.
High confidence it will become a strong strong storm with a phase of the two streams of the jet stream.
High confidence impact to us with regard to snowfall will be light if any.
Best chance of significant snow from this is for folks in Down East Maine and Nova Scotia.

I think we need to look beyond the 2/5 time frame for next shot at snow.
There is decent ensemble agreement for +PNA/-NAO developing.  This combo you look for at especially at the coast.  It slows the atmospheric flow down and tends to trap cold high pressure for much longer periods of time.  Cold air will also be in greater supply due to -EPO preceding this time frame.  Western Atlantic Ridge also would prevent the OTS escape of a storm.

If and that is a BIG IF we get anything like this look the coast will have its best shot at significant snow since March 2019 in this incredibly hostile pattern we've had since mid December.

[Radz]

What does that mean aiannone and Radz?

Just means you don't need a paid subscription to view those model runs on Pivotalweather...

[jmanley32]

That's cool I'll check that out.

[Frank_Wx]

Low confidence remains for any coastal storm this weekend. If we had a better timed PNA spike it would have tugged the storm west. Instead, there is a 'kicker' crashing into the PAC NW that forces the ridge east and throws everything off downstream. Also, the AO/NAO are positive during this time. As mentioned, depending what happens with the Stratosphere, a pattern change remains on track for after February 4th.

[heehaw453]

Low confidence remains for any coastal storm this weekend. If we had a better timed PNA spike it would have tugged the storm west. Instead, there is a 'kicker' crashing into the PAC NW that forces the ridge east and throws everything off downstream. Also, the AO/NAO are positive during this time. As mentioned, depending what happens with the Stratosphere, a pattern change remains on track for after February 4th.  

I'd be more interested in the energy that swings through on the backend of this quite honestly.  This model solution wouldn't even affect Nova Scotia.  Trough is way too positive.  I think modest accumulations could be possible as the trough swings through the area.  Air column would be cold enough at that point.

[heehaw453]

Watch this northern stream back end energy as it swings through on the Euro.  That could give some a few inches if it holds together and swings a touch south. That to me is a lot better chance ATTM on rendering snow.

I'd give the coastal idea until Wednesday before dismissing it.

[docstox12]

Watch this northern stream back end energy as it swings through on the Euro.  That could give some a few inches if it holds together and swings a touch south.  That to me is a lot better chance ATTM on rendering snow.  

I'd give the coastal idea until Wednesday before dismissing it.

If that gives us all a few inches, I will take it in this snow starved time.

[bobjohnsonforthehall]

Is it possible that the high that heads off the coast can turn the wind to the south, and that plus dynamic cooling from a perfectly placed low could create the right conditions? Just spitballing here. But perhaps that would be a way to get this done without a phase with the northern stream?

So much has to go right. My guess is cold rain at this point, but it's just a guess.

[heehaw453]

Is it possible that the high that heads off the coast can turn the wind to the south, and that plus dynamic cooling from a perfectly placed low could create the right conditions? Just spitballing here. But perhaps that would be a way to get this done without a phase with the northern stream?

So much has to go right. My guess is cold rain at this point, but it's just a guess.

Cold rain is possible if this is pure southern stream energy and tucked in solution. That'd warm things up aloft and still have decent precip. I doubt it though. I think that goes wide right w/out northern stream pulling it up. My guess we get minimal precip from coastal and have northern stream backend as our possible way to a few inches.

[sroc4]

Is it possible that the high that heads off the coast can turn the wind to the south, and that plus dynamic cooling from a perfectly placed low could create the right conditions? Just spitballing here. But perhaps that would be a way to get this done without a phase with the northern stream?

So much has to go right. My guess is cold rain at this point, but it's just a guess.

Cold rain is possible if this is pure southern stream energy and tucked in solution. That'd warm things up aloft and still have decent precip.  I doubt it though.  I think that goes wide right w/out northern stream pulling it up.  My guess we get minimal precip from coastal and have northern stream backend as our possible way to a few inches.

A possible inverted trough scenario is possible with what you describe too.

[amugs]

Good ENS cluster of low pressures here. Ni e improved map over 0z and 6z runs.
Map from PB @ 33rain

[heehaw453]

There's definitely some room for this to come up as per GFS.  A better phase and that'd be a whole lot more.  It's a bit sloppy.  It'll be just enough to inspire interest I suppose. 

[amugs]

Navy says game on - this is just used to comparatively set against other progressive models - the GEFS agree





Its gonna waffle - the pieces of energy are over the PAC as I write so LOTS of time with this, can break any which way.

No definitive statements at this time just sit back and watch it play it..

There is so much energy (4 to 5 pieces) flying around east of the Rockies its literally chaos for the models at this juncture

[billg315]

I’ll hold off until Thursday on getting excited or pessimistic. Way too early to get a fix on this yet.

[jmanley32]

True bill, even then theres still a large magin of errror, aren't we talking monday? Thats 7 days away.

[Irish]

I thought it was Saturday into Sunday.

[sroc4]

Monitor the ridge out west. Frank mentioned this as well. There has been a little bit of a trend in flattening it a little lately which keeps our southern and northern energy separate. But with 5-6 days to go plenty of time to watch. Timing of a fairly potent bit of vorticity into the N CONUS seems to be important in determining if it will flattery the ridge too quickly. The steeper the east side of the ridge the stronger the northern energy will dig. Of course timing with the southern energy is imperative. Again very complex set of interactions the likes of which will take some time before we see the final soln.

[sroc4]

Yes it is sat into Sunday if there is a bigger storm. If that one slides south of us Sunday into Monday could still produce via an Inverted trough (IVT) or northern energy that throws moisture back as it deepens when it reaches the Atlantic.

[jmanley32]

Monitor the ridge out west. Frank mentioned this as well. There has been a little bit of a trend in flattening it a little lately which keeps our southern and northern energy separate. But with 5-6 days to go plenty of time to watch. Timing of a fairly potent bit of vorticity into the N CONUS seems to be important in determining if it will flattery the ridge too quickly. The steeper the east side of the ridge the stronger the northern energy will dig. Of course timing with the southern energy is imperative. Again very complex set of interactions the likes of which will take some time before we see the final soln.

Yep, very fine line, well explained, gonna just let it play out and once its moving in and WSW are posted i'll get excited.

[amugs]

Remember we have a height rise with small N NAO block forming that is trending slightly stronger which can help help combat the PNA being deamplidied. Time will tell.

[SoulSingMG]

00z GFS!

That’s it, that’s the post.

[Irish]

What's the 00z GFS saying?

[heehaw453]

0Z GFS really bombs out well.  Very organized storm that matures on the approach to just inside the BM (drops over 20mb is 12 hours).  Rapid intensification occurs on the way to BM which puts our area on NW side where you'd get good banding.  It continues to intensify even after the BM.  

The key is the trough is much more neutral, digs and the energy gets out ahead of that trough quite well.

Sure, why not.  I'd take the 6"+ it just gave me. Most would do well with the scenario. I'll continue to temper expectations until I see some consistency which won't be until Wednesday most likely.

[SoulSingMG]

What's the 00z GFS saying?

She’s been shifting west all day with better phasing and this run was no exception.

[Irish]

I'm gathering the storm had been off the coast too far to make a great impact and now it's getting within greater striking distance?

[heehaw453]

It just nukes SNE.  It's still maturing up until Maine.  How many Miller A storms mature all the way from North Carolina to Down East Maine?  Cannot think of too many quite honestly.

[heehaw453]

I'm gathering the storm had been off the coast too far to make a great impact and now it's getting within greater striking distance?

Still way too early to know anything definitive. I think by Wednesday night we know better if this is something to get excited about. Too much model inconsistency ATTM.

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