March Mid/Long Range Discussion 2

[Ji]

with all the negative talk...this setup and potential is as good as weve seen since January 2016. It has HECS potential

[Interstate]

and it just sits there and spins and spins. Basically in the same spot for 30 hours

[Thanatos_I_Am]

Just now, Interstate said:

and it just sits there and spins and spins

Imagine if it were hugging the coast 

[Ji]

Just now, Interstate said:

and it just sits there and spins and spins

its a powder keg...this is where we really need the blocking to do its dirty work. Get that 500mb 100 miles south and we can get a 1-2 foot snowstorm

[psuhoffman]

6 minutes ago, Ji said:

well...its a disaster but its not the nuclear disaster. so much for the ensembles 

Relax...the h5 low did a weird stall & split that hurt us. Could that happen sure. But if it's consolidated that low is tucked in against ocean city dumping on us not 150 miles east. That's actually a correction I would expect. 

[psuhoffman]

1 minute ago, Thanatos_I_Am said:

Imagine if it were hugging the coast 

It should be. I doubt what it did to swing it out before the capture. 

[Vice-Regent]

Just now, psuhoffman said:

It should be. I doubt what it did to swing it out before the capture. 

Shades of Hansen in this run. It's rare to see it.

[cbmclean]

1 minute ago, Ji said:

its a powder keg...this is where we really need the blocking to do its dirty work. Get that 500mb 100 miles south and we can get a 1-2 foot snowstorm

Well, this SE forum member is rooting for you guys; ride this thing to glory.  Maybe we can all get some good juju for next year's, non-Mega-Nino/non-Nina winter.

[Interstate]

From 162 to 198 before it starts to move south

 

Talk about beach erosion

[WestminsterSnowCapitalMA]

a storm two runs in a row. This hasn't happened since 2010

[Ralph Wiggum]

Shades of Hansen in this run. It's rare to see it.

Mmm Bop?

[Interstate]

so I am guessing the Euro was a disaster?

[showmethesnow]

6 minutes ago, Interstate said:

so I am guessing the Euro was a disaster?

Somewhat similar to what we are seeing now. Drives the primary into the Lakes with secondary development off the coast around the Md/Del shores. Temps are not agreeable. Both op and ensembles are similar. See a slight bump up with the snowfall means and there are no post worthy ensemble members really worth throwing up on the board.

[Mordecai]

19 minutes ago, Interstate said:

so I am guessing the Euro was a disaster?

After going through the 51 members...not really anything worthy to post.

[showmethesnow]

To give you an idea of what we are dealing with when it comes to our day 7 storm thought I would throw up the last 4 runs of the GFS. 

This is yesterday's 06Z run at 144 hrs. Notice the arrow extending from the SE up into southern Canada? This is strong ridging in front of our trough diving down into the central US. Not only does the ridge drive warm air northward through our region it will also exert force on the trough slowing and attempting to shunt it northward. This is not a good look for snow chances in our region. 

 

Yesterday's 12Z is very similar to the 06Z but the ridging (arrow) in front is a touch weaker. Still not a good look but marginally better.

 

Now looking at the 18Z. We see a pretty meaningful change in regards to ridging. Notice that we now see a weakness driving through the ridge that did not exist on the previous runs. So we now have weaker ridging in the southeast and blocking higher pressures to the north in southern Canada. The effect of these changes is that the trough/closed low will tend to be quicker and will tend to travel more towards the weakness between the blocking higher pressures to the north and the ridging in the SE. This is a good look for snow chances in our region if temps cooperate. The breaking down of the ridging both helps to mitigate and/or shut off the southerly warm air flow through our region as well as to drive the trough/closed low farther SE putting it in a better position for what looks to be a coastal development.

 

Now we have the 00Z. Notice we once again see the ridging in front and though weaker it is still whole progressing from the SE up into Canada. But the 00Z does shortly break down that ridging and we end up with a look that is somewhat decent though temps may be more of an issue then the 18Z because we have a longer period of warm flow from the south. The 00Z is pretty much a compromise solution between the 06Z/12Z and the 18Z.

At this point indications are strong that we will be dealing with strong ridging leading into our possible storm. How it handles that ridging will most likely be key to our snow chances. The closer we verify towards the 18z solution the better our snow chances and conversely the more it looks like the 06Z/12Z the worse our chances. 

eta: The Euro has a somewhat different look at 500 mb but in regards to the ridging, which I believe will be key, it holds on strong as the 06Z and 12Z do.

 

[rcflyermd68]

at least  the west  coast low is not right on the coast  which seems to be a critical part of where our low will form, as others  seem to  indicate.

[showmethesnow]

06Z has a lot of teases thrown at us. But we have very little to show for it on the snow maps as we generally fall on the wrong side of things. Would definitely take its 16 day run and roll the dice. If things were to break right it would be a very memorable stretch.

[showmethesnow]

Nice bump up on the 06Z GEFS vs. 00z snowfall means for the day 7 storm though not to the extent of the 18Z. A few nice members in the mix.

[Thanatos_I_Am]

6z GFS is just warm. How come?

[showmethesnow]

7 minutes ago, Thanatos_I_Am said:

6z GFS is just warm. How come?

Without looking into it my guess is because the ridge in the east holds on to long. Unlike the 18z which breaks it down rapidly shutting off for the most part the warm southerly flow the 06 holds onto it for longer allowing this southerly flow to continue further warming our region. One other aspect is the fact that the 18z starts breaking down the ridging and the southerly flow on the west side of the Appalachians so we never get a truly strong southerly flow on the east side.

[psuhoffman]

13 minutes ago, Thanatos_I_Am said:

6z GFS is just warm. How come?

Warm boundary layer, rates never overcome...its very close.  BUT... that H5 argues for a much better surface result then that.  The GFS IMO on that run is doing its typical nonsense where it fails to have enough precip on the west side of a strong system.  There is no reason for the surface reflection to be that disorganized and weak.  I wouldn't worry about it...if that h5 setup is right we would be ok IMO.  

[psuhoffman]

1 minute ago, showmethesnow said:

Without looking into it my guess is because the ridge in the east holds on to long. Unlike the 18z which breaks it down rapidly shutting off for the most part the warm southerly flow the 06 holds onto it for longer allowing this southerly flow to continue further warming our region. One other aspect is the fact that the 18z starts breaking down the ridging and the southerly flow on the west side of the Appalachians so we never get a truly strong southerly flow on the east side.

That ridging is pretty inevitable.  With the exception of one run its on everything across all guidance and even the 18z GFS had it just weaker... We are going to need a good H5 pass here to crash the temps.  But that looks on the table.  But without that we have no chance.  

[LP08]

50 minutes ago, showmethesnow said:

Nice bump up on the 06Z GEFS vs. 00z snowfall means for the day 7 storm though not to the extent of the 18Z. A few nice members in the mix.

Taking a look at low locations, I figured they would be much better than they show.  The transfer happens much quicker at 06z then 0Z on GEFS.  Is it just those lows never really get going, like the OP?

[psuhoffman]

Some thoughts after looking over all the guidance...some good some bad

I have started to take the last 4 runs of the GEFS as one super ensemble in my mind to offset the hive mind problem.  If we do that we have had 2 really good runs and 2 so so ones.  But I like the overall idea of what the GEFS is doing with the H5 setup day 6.  The Euro is awful with that and evolves totally different and if it is correct there is no day 6 threat but there would be a threat around day 10/11 but even that threat is low.  We want the GFS look not the euro here.

The difference starts at only 72 hours so we are gonna see one or the other cave soon.  The GFS suite ejects the h5 energy and associated surface system significantly south of the euro.  The JMA and NAVGEM are in the gfs camp with that.  The CMC and ICON are with the euro.  They eject that system out of Wyoming into south dakota and from there its game over.  The GFS ejects out of southern Colorado into Kansas.  

I have seem some focus on the weakness in the high latitude ridging (JB) but I don't think that is the key.  The CMC for instance doesn't have that weakness yet still ends up north and a mess.  The NAVGEM does have it and still digs south.  That weakness does play a part but its symbiotic not a cause.  Once that upper low gets all the way up into Minnessota there is very little chance its going to dig...and then yes with that weakness in the ridge there it will link up and then its really not going to dig.  But if the upper low is down over Missouri instead then its irrelevant.   Where that system actually ejects out of the west is more the issue IMO.

I think IF the gfs idea of a more south track of that is correct I really like our chances.  I think the gfs is having issues bringing the system together at the surface and is jumping the surface low too far out on the 0z run and on 6z simply never gets the ccb going enough to overcome temps.  But I see that trending better as we get closer IF....bit IF the gfs is right about the h5 setup and getting that h5 low to track just under us.  

If the north camp is right that day 6 setup just isnt going to work.  Our best chance in that setup would be if the front clears and as the upper low stalls and elongates in response to the blocking something else might dig down the back side of the trough and amplify a day or two later...that would be our only hope.  

I am still about the same place I have been all along.  Odds still favor NOT getting a big snow but the chances are way above normal climo so we have a chance and that is all we can ask for this time of year.  I have remained somewhat optimistic that we have a decent shot at something but not to the "its likely" level pretty much for the last 10 days.  I am not getting too high or low with each run.  

That said we are getting to the point where things will start to break one way or the other.  The day 6 threat might resolve itself today considering the important parts diverge at only 72 hours.  After that the next threats are breaking inside day 10 now when the setup typical becomes slightly more clear on guidance... So within the next couple days things will either go from murky to "this really might happen" or from murky to "oh well it looks like its not coming together".  We will see.  

[showmethesnow]

18 minutes ago, LP08 said:

Taking a look at low locations, I figured they would be much better than they show.  The transfer happens much quicker at 06z then 0Z on GEFS.  Is it just those lows never really get going, like the OP?

As PSU stated above I think it has more to do with the surface reflection of the low running through the region. It looks weak and disjointed. I am with PSU on this though in believing we should see a stronger system with what the model shows. Think the far bigger issue potentially with what is shown is temps and not so much precip which is on the lighter side. Even with better precip rates to cool the levels I still think we could have temps issues in the lower levels. To far out to really delve into that though.

[pasnownut]

19 minutes ago, showmethesnow said:

As PSU stated above I think it has more to do with the surface reflection of the low running through the region. It looks weak and disjointed. I am with PSU on this though in believing we should see a stronger system with what the model shows. Think the far bigger issue potentially with what is shown is temps and not so much precip which is on the lighter side. Even with better precip rates to cool the levels I still think we could have temps issues in the lower levels. To far out to really delve into that though.

throw us a stemwinder or 3 and let dynamics work their mojo.....

I'm in....

 

[showmethesnow]

1 minute ago, pasnownut said:

throw us a stemwinder or 3 and let dynamics work their mojo.....

I'm in....

 

Just looked over the temps on the 06z and they aren't as bad as I thought they would be. Seeing mid fortys for surface highs leading into it. Has a fairly deep warm layer from the surface to 925 but with rate and time that could/would be overcome. Could very well be a case of heavy rain to pasting snow solution if we have a stronger low then currently projected. But 7 days, not really worth digging too deep into temps until we have a better idea how the models want to handle the ridging and the trough/low dropping down.

[Bob Chill]

36 minutes ago, showmethesnow said:

Just looked over the temps on the 06z and they aren't as bad as I thought they would be. Seeing mid fortys for surface highs leading into it. Has a fairly deep warm layer from the surface to 925 but with rate and time that could/would be overcome. Could very well be a case of heavy rain to pasting snow solution if we have a stronger low then currently projected. But 7 days, not really worth digging too deep into temps until we have a better idea how the models want to handle the ridging and the trough/low dropping down.

The only thing I'm watching is whether or not the GFS is "more right" with the ull pass than other guidance. 3 runs in a row is a good sign but as we all know....things came fall apart at any time with this much lead time. Discussion about fine details of SLP evolution and such is best left until we actually know we're going to get a favorable ULL pass overhead or to the south. 

[pasnownut]

16 minutes ago, Bob Chill said:

The only thing I'm watching is whether or not the GFS is "more right" with the ull pass than other guidance. 3 runs in a row is a good sign but as we all know....things came fall apart at any time with this much lead time. Discussion about fine details of SLP evolution and such is best left until we actually know we're going to get a favorable ULL pass overhead or to the south. 

true that.  Just looking for storm evolution...not parsing details.  Hoping 12z's keep us interested.

[psuhoffman]

20 minutes ago, Bob Chill said:

The only thing I'm watching is whether or not the GFS is "more right" with the ull pass than other guidance. 3 runs in a row is a good sign but as we all know....things came fall apart at any time with this much lead time. Discussion about fine details of SLP evolution and such is best left until we actually know we're going to get a favorable ULL pass overhead or to the south. 

We will know soon...it diverges from the euro at only 60 hours now.  They both come ashore in Oregon but then the GFS digs southeast while the euro does a pinwheel and pulls northeast with the upper system.  GFS will either cave or stick with the next frame this run.  But they can't stay apart too much longer given the difference starts at only hour 48 now.