October/November Mid/Long Range Disco

[Wonderdog]

That's  a massive 1042 HP feeding cold air into a LP system. Nice outlook for the mountains and Pittsburgh area, as well as Cincy and southern  Ohio. Wouldn't take much to change to let our area to see some white stuff falling.

[AfewUniversesBelowNormal]

Check it out though

[AfewUniversesBelowNormal]

NAO going negative just in time for the Winter..

[AfewUniversesBelowNormal]

What a pattern

[Maestrobjwa]

9 minutes ago, AfewUniversesBelowNormal said:

NAO going negative just in time for the Winter..

What makes you say that?

[AfewUniversesBelowNormal]

2 minutes ago, Maestrobjwa said:

What makes you say that?

trends, all the mb's around this low (remember last March)

[nj2va]

Looks like some upslope snow showers for the mountains overnight Friday into Saturday according to the GFS. 

[AfewUniversesBelowNormal]

I like the 252-300hr timeframe for a snowstorm. Check out the 934mb low. This is probably model feedback for a favorable time period, and could be 980s-990s off the coast. 

[NorthArlington101]

0z GFS has a little bit of snow in the immediate metro area next Tuesday... it’s a start. Coastal exists again but way too far off the coast to be super interesting.

[Heisy]

1 hour ago, AfewUniversesBelowNormal said:

I like the 252-300hr timeframe for a snowstorm. Check out the 934mb low. This is probably model feedback for a favorable time period, and could be 980s-990s off the coast. 

Not sure how that low in Canada being a “feedback issue” would have to do with things. Unless you are coorelating it with a 5050 low? Anyway that image verbatim wouldn’t be good for snow. You don’t get snowstorms in our region with LP banana’d into the lakes and a HP off the coast.

That setup could work in January where you have a parting HP which leads to moisture riding a warm front into CAD. However, verbatim that image you posted is not even close to anything really, especially in Nov.

Dont get me wrong I like the pattern coming up next week, but we would need to really get lucky with timing between short waves and wave lengths etc. 

 

 

 

[showmethesnow]

Early next week is starting to get my attention just a little bit. We are seeing changes with how the Euro is now handling the pv drop southward which makes a big difference on how it handles the possible coastal development early next week. Below we have the initial pv drop from the Sun 12 z run. Notice how it dumps everything into the drop towards the Can/Us border. But the runs since have been shifting to a different handling of this.

 

This is last nights 00Z run. Notice now that we have the main portion of the pv held back towards central Canada with an extension protruding from it down to the border. Watch how this changes the evolution of the trough that sets up for our possible coastal.

 

This is Sundays 12Z. Notice that the pv is wholly intact and now sliding up towards southern Greenland as it progresses towards being absorbed into the main pv situated over the pole. This in turn is creating a flat flow underneath with very shallow and broad trough starting to develop in the central US.

 

But look at the changes we have seen the models move to with the latest run. We are now seeing a distinct split with the pv, one portion hanging back allowing easier access for follow up energy to surge southward and the other portion swinging farther southeastward closer to the 50/50 region vs the above run. Now this is having an important impact on the flow in front of the developing trough. What we are now seeing is ridging developing between the developing trough and the portion of the pv rotating up towards Greenland. This is important as it kinks and slows the flow which will have an impact on the developing trough in the central/eastern US.

 

Now below we have the setup from Sun 12Z run as the possible low is off the coast. Pv has been absorbed into the main portion over the pole and we are seeing no backing/slowing of the flow. This is a losing look. Trough is positively tilted and the flow is flat and out to sea. Any storm development in this setup has a very high likelihood of being a fish storm. But look at the differences we see from the overnight run below.

 

Now this look has potential. Probably still not there but it is getting close. What we have seen is that the break-off piece of the initial pv drop has now rotated up off of southern Greenland vs. getting absorbed in the main portion of the pv as in the previous example. So what we are seeing is that it is creating a backing of the flow as to where we are seeing somewhat decent ridging developing in front of the eastern trough. This in turn is creating a deeper and sharper trough as well as to help turn the trough to a neutral tilt. But as I said, I don't think it is quite there yet. What I would like to see is a wider swing south and eastward of the break-off pv where it swings closer to the 50/50 region on its trek northeastward. If we can get that we should see better ridging in front of the eastern trough to develop which should in turn help to turn the trough negative tilt quicker. One thing that could help with a wider swing of the break off pv is if we see the ridging and higher heights over central Greenland actually coming in stronger.

 

Now I used the mean 500 maps above for a better contrast to show what I was discussing. But below is the anomaly maps for when the storm is off the coast for those who are interested.

 

 

Here is the mean mslp from last nights run. It has taken a huge step towards seeing coastal development.

 

Now just getting a good setup for any possible storm is just half the problem. The other half is fighting climo temps. But at this point let's just worry about having a storm impact the region and worry about temps later.

 

[midatlanticweather]

Very good discussion @showmethesnow

[showmethesnow]

We are seeing something very similar occur with the latest GEFS vs. yesterdays 06Z run as I discussed with my previous post on the EPS.

Yesterdays run

Todays

[midatlanticweather]

Bernie Rayno is starting to speak about a storm.. he is rightly speaking of climo areas of interior New England for any chances of snow. You never know, but you know Climo, so you kinda know!

[midatlanticweather]

 

[Maestrobjwa]

15 minutes ago, midatlanticweather said:

 

Boo for the +NAO....gotta be the most stubborn one we've had in recent memory!

[aldie 22]

9 minutes ago, losetoa6 said:

I can't believe nobody mentioned the Euro for next Wednesday...its totally off the hook . It's spitting out high 20s low 30s for highs with NW winds gusting to 45+.  Winter anyone ? 

Because it will be 90 the following week 

[CAPE]

A brief cold(dry) shot with a hard freeze is kinda fun, but it is transient, and beyond that there is some work to be done to get to a decent h5 look as we head into December.

[showmethesnow]

Seeing comments about a warm T-Day incoming. Just a flyer on my part but I am not so sure that is a given quite yet. Besides the obvious, that the models can and will change especially at longer ranges (2+ weeks), I think there may be some hope shown within the model itself that this may not be the case. Below is day 15 on the EPS. Notice the higher heights (these strong anomalies begin building day 8) in Europe but the muted ridging? With the very strong anomalies I question whether the ridging is getting smoothed out by some other members in the longer range. One thing that leads me to believe that the ridging may be stronger then shown (-NAO) is that we see strong negative anomalies that move into and off shore of southern Greenland and something is locking it there from day 9 through the duration of the run. Now if this is in fact the case (ridging into Greenland with low pressures trapped underneath) then the flat flow we see running through the CONUS should look very different. Instead with that setup around Greenland we would typically see pronounced troughing in the east with ridging in the west. This would mean a warm west and a cold east. Of course this is all just guess work on my part and I could very well be wrong. So don't be putting your swim suits away just yet. 

 

 

 

[CAPE]

21 minutes ago, showmethesnow said:

Seeing comments about a warm T-Day incoming. Just a flyer on my part but I am not so sure that is a given quite yet. Besides the obvious, that the models can and will change especially at longer ranges (2+ weeks), I think there may be some hope shown within the model itself that this may not be the case. Below is day 15 on the EPS. Notice the higher heights (these strong anomalies begin building day 8) in Europe but the muted ridging? With the very strong anomalies I question whether the ridging is getting smoothed out by some other members in the longer range. One thing that leads me to believe that the ridging may be stronger then shown (-NAO) is that we see strong negative anomalies that move into and off shore of southern Greenland and something is locking it there from day 9 through the duration of the run. Now if this is in fact the case (ridging into Greenland with low pressures trapped underneath) then the flat flow we see running through the CONUS should look very different. Instead with that setup around Greenland we would typically see pronounced troughing in the east with ridging in the west. This would mean a warm west and a cold east. Of course this is all just guess work on my part and I could very well be wrong. So don't be putting your swim suits away just yet. 

 

 

 

 I see a blocking ridge over Scandinavia, which means there would be a trough near/over GL. I do agree the persistent low heights near the 50-50 position would typically imply higher heights further west into GL. Could be a bit of a conflict among the members. Something to watch for sure- and it is pretty common for ridging in that region to retrograde more towards GL with time.

[showmethesnow]

11 minutes ago, C.A.P.E. said:

 I see a blocking ridge over Scandinavia, which means there would be a trough near/over GL. I do agree the persistent low heights near the 50-50 position would typically imply higher heights further west into GL. Could be a bit of a conflict among the members. Something to watch for sure- and it is pretty common for ridging in that region to retrograde more towards GL with time.

Probably a better view. If that ridging comes in stronger what we would probably end up with is an East based -NAO.

[Maestrobjwa]

2 minutes ago, showmethesnow said:

Probably a better view. If that ridging comes in stronger what we would probably end up with is an East based -NAO.

You think a -NAO is still on the table?

[CAPE]

30 minutes ago, showmethesnow said:

Probably a better view. If that ridging comes in stronger what we would probably end up with is an East based -NAO.

Yup. I, like you, am always rooting for the (elusive) -NAO. I believe it is especially important for our region, and more so for I-95 and east for a favorable storm track. I am probably more focused on PV weakening/ development of a -AO at this point. If we get that, then odds increase that NA blocking will follow, as the 2 indices are closely correlated and share (partly) the same domain space.

[CAPE]

4 minutes ago, Maestrobjwa said:

You think a -NAO is still on the table?

We should see a legit -NAO at some point. Probably a better chance of persistent NA blocking during the second half of winter, esp Feb into March.

[showmethesnow]

7 minutes ago, Maestrobjwa said:

You think a -NAO is still on the table?

The ever elusive -NAO. Persistence would say no. I myself feel that we will see a -NAO this winter especially in the second half of the winter. I liked some of the things I saw leading into the winter but I especially like seeing the persistent ridging/higher heights in western/central Europe which can often translate to a -NAO.

[CAPE]

2 minutes ago, showmethesnow said:

The ever elusive -NAO. Persistence would say no. I myself feel that we will see a -NAO this winter especially in the second half of the winter. I liked some of the things I saw leading into the winter but I especially like seeing the persistent ridging/higher heights in western/central Europe which can often translate to a -NAO.

Yes there is that, but also if we get a legit -AO developing over the coming weeks, along with continued decreasing solar/geomagnetic activity, a -NAO should be favored as we progress towards mid winter and beyond. The QBO might be a thorn in the side of this idea as it seems to be headed into positive territory.

[nj2va]

38 minutes ago, Maestrobjwa said:

You think a -NAO is still on the table?

For when?  We should see -NAO this winter, my guess especially towards February.  

[Maestrobjwa]

29 minutes ago, C.A.P.E. said:

Yes there is that, but also if we get a legit -AO developing over the coming weeks, along with continued decreasing solar/geomagnetic activity, a -NAO should be favored as we progress towards mid winter and beyond. The QBO might be a thorn in the side of this idea as it seems to be headed into positive territory.

Positive territory for the short term orthe long term?

[CAPE]

17 minutes ago, Maestrobjwa said:

Positive territory for the short term orthe long term?

From what I know it is a fairly regular periodic cycle- so once the wind changes direction it tends stay there for a while, growing in magnitude then decreasing again.. It roughly resembles a sine wave, although it tends to shift more abruptly and is not necessarily symmetrical(positive and negative alternations).

[Maestrobjwa]

11 minutes ago, C.A.P.E. said:

From what I know it is a fairly regular periodic cycle- so once the wind changes direction it tends stay there for a while, growing in magnitude then decreasing again.. It roughly resembles a sine wave, although it tends to shift more abruptly and is not necessarily symmetrical(positive and negative alternations).

So we shouldn't count on it to help us this winter?