showmethesnow

By hour 126 NE Suppression is pulling out a little quicker with stronger/quicker heights builds in the east. Should be coming north. Let's see how far though.

This isn't a hateful look whatsoever. This is the 06Z GEFS days 7-15 and besides some minor differences this is a pretty accurate depiction of what the GEFS has been throwing up for awhile now. Now compare the 00Z euro for that same period of time. Very similar to the GEFS except for how it is handling the PAC in particular in the NW and Alaska (black circle) and the corresponding response with the ridging in the central US. It is not as aggressive with the PAC ridging and we see lower heights over spreading Alaska from the PV to its north. This difference is why we are seeing such discrepancies with the temp maps below. Now I want to point out one thing I have an issue with. Notice we are seeing a pretty stout west based -NAO as well as corresponding lower pressures through the 50/50 region as lows pass through. What doesn't jive is the lack of backing we are seeing with the flow. I can understand to a point how an overwhelming PAC flow can mitigate the response we should be seeing from the blocking but this is probably over kill. In my mind we should be seeing more troughing in the east then currently depicted as well as better ridging in the NW. Those plus height anomalies should be stretching farther east (red circle). And if you haven't caught on by now, if you do show the better backing of the flow we end up with a very similar look as the GEFS. Now if you look at the GEFS temps anomalies you can see the better cold in the northern tier as well as seasonal to slightly below draped down the east coast. Pretty much a signiture of the better backing we are seeing with the GEFS. EPS on the other hand is showing very little backing and you can see what the response is as we see the CONUS flooded with warm anomalies. Now to show you the potential that the GEFS has to offer, here is the snow map for days 8-15 (just after the possible coastal we have been tracking). Keeping in mind that this map (Guess it is supposed to be a mean map) is most times grossly underdone in the extended when it comes to individual member output this is fairly impressive. Also note the southward extension of these snows. This is hardly the look of a shutout pattern. EPS actually has some interest during this period of time as well as there are enough members (1/4 to a 1/3) in play to suggest the possibilities. So the question is, which is right/more right? Know many/most on here are putting their money on the EPS. I'm not at this time. Knowing the very similar looks (as to the current GEFS depiction) that have been thrown at us up around Alaska/NW this last month/month and a half I fully expect that it will gravitate back once again though it may be rushing it a touch. Also I am not a big fan of the lack of backing we are seeing with the EPS as explained above. Also seeing some support within the EPS members helps as well. So my money is riding on the GEFS. Of course after losing the house last winter in Vegas maybe I should just quite betting.

I hate when people pee in my snow.

Stepping out the door right this second to go Christmas shopping so I will have to get back to you later.

Nice look at 500's with that system. Confluence held on long enough, maybe even a touch too long. But keep in mind the system we have coming through Monday had a somewhat similar look at this range as well.

Get that confluence in the NE to hold a little longer and it would be interesting very quickly.

I agree. I am actually liking what we are starting to see through this period (EPS advertised PAC flood) as it nears in time. But it is a fine line between the solutions given by the EPS and the GEFS for our sensible weather in the extended. And as you said a compromise is more then likely but I just happen to weight the GEFS more then I do the EPS which if true would probably put us in a pretty good place.

I don't know if I would call one day worth of warmth a torch. And that is more so for down in your local (NC) vs up in our region where the northern sections may not even get out of the 30's. Even the southern and eastern portions of the region see only a brief half day warm up at best. And this brief warm up isn't even associated with the EPS advertised PAC flood it is just a natural response of a trough moving into our region.

IF.....the GEFS is somewhat right with its evolution/timing of the PAC ridging this potentially sets us up a very sweet look for us. Now it takes more then just a sweet look to score, as there are many other factors involved. But give me this look in real time and not in model fantasy land and I would be salivating. (***Just a followup to my previous post. Look at what we are seeing in the west. PV extension west of Alaska, -EPO/+ NPNA, SW weakness/low. It should look familiar to you as we have seen it quite often so far this year. One of the reasons I favor the GEFS over the EPS at this time***) EPS is just a short step away from having a very similar look to what we see with the GEFS above. We see that ridging extending up into Alaska and we end up with that same sweet look.

I know the two maps below are ominous looking as we see a full latitude trough entering the western US. But take note with what we are seeing within the red circle as the EPS and the GEFS move forward in time. Note that we are seeing the trough hold strong from the pv down to just off the SW coast (even through the red circle) as evidenced by the height lines and stronger pressure anomalies. Also notice were the ridging has set up in the Pacific. Now let's see what the GEFS has to offer. That ridging that we see far off the coast on the EPS is much farther east on the GEFS and driving through the red circle. What this is doing is breaking down the full latitude trough and its connection to the pv to the north. So what we are seeing is essentially the beginnings of a split flow setting up as we have a building northern based PNA/-EPO over cutting the SW weakness/low. Once this sets up it effectively begins to shut off the PAC flow into the central and eastern US as we now have a mechanism for delivering cold into those regions. You can see the differences with temps between these two solutions through the torch period. EPS has almost CONUS wide warm anomalies whereas the GEFS is much more muted with even seasonal to slightly below in the east. Now the question is, which is right? Considering the key feature, the PAC ridging, starts diverging around roughly day 7 we probably won't have too long to wait. Though the GEFS may be rushing it somewhat at this time I myself favor the GEFS solution as it plays into the general look the pattern has favored into the NW and Alaska so far this season. The EPS makes a weak attempt to achieve this look and yet never gets there as it once again plants lower heights into that region at the end of the run. I just don't buy its evolution. When all is said and told I believe the impacts we will see in the East from the PAC flood will be minimal at best with maybe a day or two of a mild warmup. We may not even see that depending on whether the N Atlantic (blocking, 50/50s) can cooperate and keep some form of troughing in the east and along with that seasonal temps.

The only thing stopping this from being a big storm is the deep drop by the pv. Pull that pv northward 250-300 miles northward and we are potentially talking a KU.

GFS is almost a major weenie run. Day 13 it is setting up for another major storm once again as we see all the energy in the SW ejecting eastward. Only thing that stops it is we see a major pv drop down into the midwest and NE putting major suppression into play. As it is, it brings severe cold into the east/midwest. The whole CONUS (except for the upper Plains) is clocking in with below, to much below temps by the end of the run.

06Z GFS is still liking our storm for next weekend. Smoking the mountains to our west with up to 3 ft and giving 1 ft+ down into the cities (DC/Balt).

Was looking at the EPS thinking that it wasn't really grasping the idea of how a CONUS wide PAC torch should be run. Despite the modest warm anomalies we are seeing I saw some potential opportunities in the mix.

The differences on the overnight runs gave a good example of how much the PV and its interaction (or lack of) with the mid-latitude trough will influence our region with the day 5 storm. The GEFS below shows that the PV is interacting quite a bit with the trough and this can be seen if you follow the negative departures and how strong they are connecting the pv to the trough. This is sinking the isobars in the upper portion of the trough so naturally the ridging to the east in it's upper portions are getting bumped up as well. But we aren't seeing that with the EPS. Though we are seeing a little influence to the trough from the PV we are seeing more of its energy diverted eastward. This is effectively knocking down heights in NY up into Canada giving us a flatter flow through that region. This will tend to provide resistance for our storm to move northward. Looking at the surface of the GEFS you can see how this influences the storm. With a more N/S alignment to the front of the trough the low is given more room to strengthen and pull northward. But we aren't seeing that with the EPS. With the blocking setting up in NY/S Canada we are seeing resistance to the lows northward movement. So we are seeing the storm initially move into the general area of E Kentucky/Tenn after that is where the questions come in. Chances are good we would see a transference to the coast somewhere at this time as the low meets too much resistance with the blocking up top. How far the initial western low gets northward as well as where we see the coastal take over will play a big part on what we can expect through our region. Needless to say the northern portions of the region would be favored for the initial WAA loft snows whereas the eastern portions for any possible coastal development. Of course we would more then likely also encounter the dry slot between the two lows that we often see occur as the low transfers. Another wild card here is that we are now seeing the trough just to the west of this low which could also throw a surprise in there. Still a lot of questions to be answered, many of which won't be resolved for a couple more days, but at least the EPS has us in the game.

Considering the effect that chasing Day 10-16 unicorns has on Ji, following Day 25-35 ones is going to launch him into a padded cell.

Okay, I just had to.

After seeing the GFS maybe we should get a new sponsor for the GFS? eta: Hmmmm... after seeing Day 10 maybe we should keep it as a sponsor for a little longer.

@psuhoffmanLiked the shift south on the 06z EPS as well. Except for occasional glances though I haven't really been following the off runs of the Euro. Any idea how well it is verifying? Any degradation over the 00z, 12z runs?

Still seeing the day 10 storm popping up. Different look at 500s then the 06Z run and more in line with the 00Z. Would prefer this look over the 06Z as I think it offers better odds on scoring more then just a conversational snow.

Still far too much interaction between the PV and the mid-latitude trough for our needs. But as those who followed the GFS/GEFS on the storm that just passed through this was the time frame (mid-range) that the GFS/GEFS was overplaying the drop of the PV towards the US/Canadian border. If we see that same bias play out here we probably end up with a pretty good look as we see a further north solution with the PV thus less interaction..

And you know I am just fooling with you.

I don't think that was the only thing that was high. Some have got to quit sniffing that glue.

May not seem like it, especially if you look at the surface and snowfall maps, but the Euro made a positive move at 500s on what I believe is key on next Mon/Tues possible storm. What we saw on the EPS could be nothing more then noise, but at least that noise is in a positive direction as well. Below we have the lead up to our storm when it is just to our southwest. Now assuming that the Euro is somewhat accurate with the pseudo 50/50 at this time (has been steady for the last day of runs at least) then the question is, 'what do we need to see?'. I think it all boils down to with how much, if any, interaction we see between the Mid-Latitude trough and the PV. Currently as depicted the more interaction between these features the sharper and farther west we will see our storm cut. And short of seeing the models shift those two features eastward several hundred miles the current projected farther westward placement (far from ideal for our current needs) argues for a cutter. That brings us to what we saw as far as run over run changes from yesterdays 12Z run and the overnight run. This all pretty much ties in with my comment of why yesterdays 00Z run had such a good solution. And that has to deal with needing to see higher heights then currently projected separating the PV and the mid-latitude trough. In simple terms the higher the heights between these two features the less interaction we will see between the two. Now you can get the feel for this by comparing below to what we saw from yesterdays 12z (2 maps below). If you note we were seeing the stronger height anomalies joining the PV to the trough on the 12z. And yet when we look at the latest run we are seeing a disconnect between these greater neg anomalies (red circle) this is telling us there is less interaction going on. To give you a clearer idea of the heights changes we are seeing look 3 maps below where we have the run over run changes. As can be seen we are seeing higher heights showing up between these two features. Current run 500s Now some may ask, 'If we are seeing the changes we need then why did we see a degradation with the surface with the low cutting further west?'. That has to deal with energy we are seeing rotating through just underneath the higher height builds we have seen (circled shortwave above). It is timing well to drop into the backside of the trough deepening the upper latitude portions of the trough. The response is to see a goosing of the ridging in the east in the upper latitude portion of it as well(can be seen on the run over run changes map below). These two in combination are creating a steeper N/S axis on the front side of the trough. This does two things. It pulls the boundary quicker to our north as well as gives more room for the southern low to intensify quicker with a sharper northward movement. Now to worry about this energy at this time is pointless (almost 6 days out). Models don't handle these packets of energy well at leads and it is just as likely we see this feature running ahead of the trough knocking down the ridging/heights in the east helping to keep the southern low from cutting. That is if this energy even exists. One final comment about the top map. Notice where we see the 50/50 located and how it gets there (black arrow). Not the greatest path, timing and location for what is considered a transient low. It helps the cause upstream through our region somewhat but it could do more. We see that swing farther to the south and east (red arrow) it improves the placement as well as the timing between it and the incoming central US trough. Yesterday's 12 z run Run over run changes One final comment. For those that have already given up on Mon/Tues, I probably wouldn't. That time period is still very much in play. Barring a major reshuffle on the setup the look being presented is a very winnable one with just some minor changes.