Re: Long Range Thread 18.0

[heehaw453]

The NAM is still trying to sell 1-3" of snow on Friday especially from 195 points south.  I would have thought it'd given that up by now.  There is just not much support for it.

Actually a few models like that possibility. I'm in no way advocating for any of them, but for the sake of convo:

NAM keeps the lp center like 200 miles SE of NJ, but drops 1-3" of all snow with an expansive NE precip shield.

The CMC brings the LP up the coast, with a 1-3" front end of thump to most of the forum, before changing to all rain.

And the NAVGEM indicated several hours of snow for southern NJ more in line with the NAM, a glancing blow on the northern edge of a system.

A system that all 3 of these models have bringing an easy 6"+ of white gold to Maryland and Northern Virginia...again! lol!  


GFS gives it no shot from the start.

I think the latest SREF is now inline with 12Z NAM. It definitely has been ticking north on most guidance today.

[SENJsnowman]

Short range at this point. These northern fringe events for southern NJ/PA has been a trend for the past 6 weeks. A trend of duck fart snow storms, but a trend nonetheless.

See what happens...

[SENJsnowman]

Funny enough heehaw, I think the GFS is the only model on tropical tidbits not showing snow for the Philly-Toms River corridor on South. lol

[heehaw453]

Funny enough heehaw, I think the GFS is the only model on tropical tidbits not showing snow for the Philly-Toms River corridor on South. lol

18Z NAM showing 1-2" for pretty much most of NJ.  Not a big deal, but may be nice to coat the ground.

[sroc4]

1) -EPO Ridge
2) Tropospheric polar vortex(TPV)
3) spoke of energy within the trop vortex that is the steering mechanism for our storm
4) The energy that is our system
5) 50/50 low?  On the Euro but not GFS


Using the key above we first have to monitor the ridging in the NW North America(1).  As we approach the weekend it builds or shifts from Alaska to the S and E.  How much seems to in part what helps to govern where the TPV is centered(2).  Can the strength and position of this blocking be enough to trap the TPV in a favorable position without much help from the North Atlantic side(+NAO)?  As you can see it is a bit further N on the euro relative to the GFS.  The result is a western track via the euro vs an eastern track via the GFS.  A subtle difference but an important one as the further N and west its centered the more room for our energy to cut.  The further S and or east the further S&E is the track.  Combined with other factors of course.    

In addition focus on number 3 and 4.  3 is our steering energy, and 4 is our storm energy.  The timing, positioning, and strength of 3 and 4 relative to one another is important.  We want to see 4 out ahead of 3 which is consistently modeled at this time.(details yet to be determined)  

Wild card is if there is a 50/50 type low and how it affects the big picture.  Not really there on GFS but well developed ULL(upper level low) on euro.  

Next few days should start to sort this all out.  

[heehaw453]

1) -EPO Ridge
2) Tropospheric polar vortex(TPV)
3) spoke of energy within the trop vortex that is the steering mechanism for our storm
4) The energy that is our system
5) 50/50 low?  On the Euro but not GFS


Using the key above we first have to monitor the ridging in the NW North America(1).  As we approach the weekend it builds or shifts from Alaska to the S and E.  How much seems to in part what helps to govern where the TPV is centered(2).  Can the strength and position of this blocking be enough to trap the TPV in a favorable position without much help from the North Atlantic side(+NAO)?  As you can see it is a bit further N on the euro relative to the GFS.  The result is a western track via the euro vs an eastern track via the GFS.  A subtle difference but an important one as the further N and west its centered the more room for our energy to cut.  The further S and or east the further S&E is the track.  Combined with other factors of course.    

In addition focus on number 3 and 4.  3 is our steering energy, and 4 is our storm energy.  The timing, positioning, and strength of 3 and 4 relative to one another is important.  We want to see 4 out ahead of 3 which is consistently modeled at this time.(details yet to be determined)  

Wild card is if there is a 50/50 type low and how it affects the big picture.  Not really there on GFS but well developed ULL(upper level low) on euro.  

Next few days should start to sort this all out.  

Nice write up!  That ridge is delicate balancing act because it can just as easily push the TPV further SE which would suppress the energy and make it slide off the coast.  I think that's what models were showing yesterday.  I'd much rather have the -NAO for blocking, but this can still work.  We shall see how it plays out.

[heehaw453]

Move this track about 75 miles east and everyone would get clobbered. Interesting to say the least.





Two meter temps at very warmest pass of the storm

[heehaw453]

This is close to the current goal post with track. I'd like to split the difference. See how this holds up in the next few days.

[jmanley32]

[quote="heehaw453"]Move this track about 75 miles east and everyone would get clobbered.  Interesting to say the least.





Two meter temps at very warmest pass of the storm

[/quotThis is a perfect spot, look at how heavy that snow is why east? It gives me 12-15 inches, and majority of area 10-15. But it is the icon, never seen anyone really use this model.

[rb924119]

I agree with @earthlight here; the -EPO is not the be-all end-all for snow storms along the East Coast. Sure, it helps, but you need other factors to work constructively as well, and in this case, we do not that enough of that for things to work out on a large scale for our area (in my opinion). I haven’t been enthused with any of these threats for quite some time, and remain unenthused for the time being.

rb do you mean you are concerned about track and warm air? Or something else?

Both. I like an inland/Apps runner type track, which flood us with warmth after maybe (again) a little front end slop.

[rb924119]

I agree with @earthlight here; the -EPO is not the be-all end-all for snow storms along the East Coast. Sure, it helps, but you need other factors to work constructively as well, and in this case, we do not that enough of that for things to work out on a large scale for our area (in my opinion). I haven’t been enthused with any of these threats for quite some time, and remain unenthused for the time being.

I am actually going to respectfully disgree with you and Earthlight JH on this one.  Forget "-EPO" and look at the evolution and progression of the ridging in the Alaska/NW Canada region for late Sat through late Sunday into Monday.  I def believe there is probably the best potential all winter for cyclogenesis along the coast.
Im not talking about a crawler that can dump 12-24", but a 6-12"+ event is possible.  Dont ask about in your back yard yet folks as exact track makes all the difference here.    Hopefully I will have maps labeled etc later hopefully to show more of my thinking here.   It will come down to timing of two key pieces of energy. 1 involving a spoke on the TPV wheel(steering energy), and 2 the other being the Pac energy entering the West coast of California on Saturday(our system).   Also there is a rule, and its not a hardened fast rule, but a rule that states where the energy enters the west coast look for the energy to exit the EC on a similar Latitude.  

Nope, absolutely no disagreement allowed. Zilch. Zero. Nada. Lmao jk nice discussions! You’re right about the steering mechanism (3) and the 50/50 low (I don’t believe this will be a positive influence /properly located, which is one difference), but I find other features in addition to the ones that you highlighted to also be of interest, both near and far. While my analysis does lead to a conclusion of broad, yet equal offsetting functions to the northern Hemispheric waveguide, which should (theoretically) keep this system on a close to ideal track, the presence of anomalously warm water in Western Atlantic will allow the ridging to be enhanced by that flux. Add that to the ORIENTATION of the troughing over and near North America, and I think it’s fsirly easy to see my concerns for a further west/warmer track.

[Frank_Wx]

Hmmmmmm

[heehaw453]

0Z cmc is a crush job. The tpv is the key. The guidance that shows it out ahead of the energy disallows the storm from running inland. Most guidance has it that way. Euro does not.

Rb may very well be right though albeit I think there’s a limit to how far it can go west. I like coastal hugger to just inside BM.

[CPcantmeasuresnow]

0Z cmc is a crush job. The tpv is the key. The guidance that shows it out ahead of the energy disallows the storm from running inland. Most guidance has it that way. Euro does not.

Rb may very well be right though albeit I think there’s a limit to how far it can go west. I like coastal hugger to just inside BM.

I want to believe. Help me with my unbelief.

[dkodgis]

What I notice with the Euro is it has seemingly often to always moved from a snow to a rain result as we get closer to any event. I agree the pieces are there; we'll see how they come together. When I look at the long range models, I am impressed how easy it is for the pieces to get swiped off the board and onto the ground. We set them up again according to the trends and play again. Sooner or later, even a blind rooster finds a hen. I expect we will ...luck...out...sometime along the line.

[heehaw453]

0Z cmc is a crush job. The tpv is the key. The guidance that shows it out ahead of the energy disallows the storm from running inland. Most guidance has it that way. Euro does not.

Rb may very well be right though albeit I think there’s a limit to how far it can go west. I like coastal hugger to just inside BM.

I want to believe. Help me with my unbelief.

Your caution is well warranted with these kind of setups. Track is so critical here that I wouldn't feel any decent confidence until the mesos are in range. However, i do feel 75 miles inside BM is a decent guess right now. In that scenario best snows are probably NW of 95. I just think the TPV is too far ahead of the storm energy for it to pass to our west. Wrong i may be though...

[sroc4]

Regarding the 3rd-4th system:  Euro showed a subtle shift at 500mb with the positioning of the TPV.  Yesterdays position was centered over SE Hudson bay.  Last night it shifted towards James bay where the GFS has it.  The other thing to note was a subtle shift to the orientation of the eastern flank of the trough orientation.  It shifted ever so slightly more SW to NE from a more SSW to NNE orientation.  Stated another way was went from less positively tilted to more pos tilted.  We don't want it to tilt towards neutral too soon or it open up the lane for the westward track.  These shifts are very subtle, but remember small changes at 500 can lead to bigger changes at the surface.  To say the euro is trending at this stage is foolish.  Its only one model cycle.  I need to see 1-2 more days of model cycles before getting excited.  

We still have disagreement of the ULL in the N Atlantic between the GFS and Euro.  

[amugs]

As I said the other day in here - we wont know until we get these next two systems out of here before we can solidify the track for Sunday night into Monday storm. The 12-18 hour time frame before we know IMO.
The TPV orientation and location are pretty crucial since we have no help from the Atlantic side once again. The NAO block that was advertised is just that false. The EPO can only do so much. I am 50/50 on a decent snowfall for the area at this time but the TPV orientation needs to be in a good placement for this to happen with the aforementioned.
Decent PAC and crap Atlantic.
Gosh darn Dr. No has to always show up!!

[billg315]

I think this will really be the closest we've come to a major area-wide snowstorm this winter. Exact track will be huge especially for those right on the coast. If we got this track and setup in January I'd feel a lot more confident than early March, but we've all seen our fair share of these snowstorms in March so it is definitely possible. As mugs says, gotta kick these preliminary systems out before we get a good read. Could be an interesting weekend of tracking.

[heehaw453]

Yowza.  That is a death band.  12Z Icon much further SE FWIW.

[Irish]

Heehaw, so does that mean our chances have improved for a solid event?

[heehaw453]

Heehaw, so does that mean our chances have improved for a solid event?

Don't know at this point and I wish I knew.  Really depends on track of the storm and its intensification.  If it goes BM to maybe 50 miles inside BM then good snows for 95.  I think that kind of track with some deepening of the low would be enough to keep mid levels cold.  If it goes more than 50 miles inside BM, then you need to push the good snows accordingly NW of 95.  Somebody will no doubt get good snow from this.  

What I am seeing so far today is deepening low pressure off Delmarva that is close to BM track.  Except the CMC which is inside BM a bit.

edit:
I should say too the angle that this storm takes when leaving the coast is kind of important too. The steeper it is the more warm air it will try to bring in.

[hyde345]

I wouldn't trust anything the ICON shows. It's a crap model. It's going to be a close call for NYC Metro and subtle changes could mean big impacts. NW of 95 looks to do well right now. Still a ways to go on this one.

[heehaw453]

I wouldn't trust anything the ICON shows. It's a crap model. It's going to be a close call for NYC Metro and subtle changes could mean big impacts. NW of 95 looks to do well right now. Still a ways to go on this one.

Overall I agree with that, but it has sniffed things out before like this coastal potential way before other guidance.

[Dunnzoo]

I wouldn't trust anything on any of these events yet. When we have these systems all in a row so close together, the models usually struggle. I'll wait til Saturday to look at Sunday.

[heehaw453]

I wouldn't trust anything on any of these events yet. When we have these systems all in a row so close together, the models usually struggle. I'll wait til Saturday to look at Sunday.  

You are wise I am unwise and get sucked in way too early!

[sroc4]

Here is the energy that is our storm as I type:



Here is our energy entering the West Coast mid day Sat.  Details details.  Need more time.  FWIW GFS today shifted the TPV center a tad further N

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