showmethesnow

Haven't really looked at the Mesos yet. Been busy looking into the Dec 2nd period as well as what we are seeing in the extended in upper latitudes. Seeing some indications that all this panic may be for nothing.

I am so embarrassed about that weenie crack. Had some heavier rates move in a couple of minutes ago and your comment made me go out and look. Quite a few Nickle+ sized flakes bombing us right now. Probably lose them when the rates drop again but this gives me hope we actually get some decent mood flakes as this system pulls out.

No glory here. At least I haven't seen anything and I have been up since 3:30. Took a casual glance at things and would not be shocked if we do have a brief period of snow (besides what you CLAIM* to have seen ) *I know how us roll.

Looking over the 00Z runs for the system centered around the 2nd we see a degradation in all (GFS, GEFS, EPS) except the Euro. Our chances begin and end (at least as the setup is currently projected) on having strong blocking forming over top of this system in southern Canada. What we have seen though is a weakening of the higher heights in that region as energy dropping down from the arctic regions is having an impact. Below we have the 18Z that was oh so close to legit snow for the DC/Balt corridor. Notice the energy in northern Canada as well as the higher heights underneath it extending from central Canada to the western coast. This is a solid wall that will eventually force the central US storm which is trying to gain latitude to transfer to the southeast Now compare that same energy on the 00Z. We are seeing this pressing farther south and lagging somewhat from the previous run. This is probably about the worst spot we would want to see this feature as it is just slightly east of the closed low's longitude to its south. A storms natural inclination is to move NEward (barring other forcing mechanisms) as it tries to gain latitude. So we really don't need a solid wall (blocking) coast to coast, we just need to see it above and slightly to the east of a system to counter this NE inclination. And if you look below the shortwave is breaking down this blocking exactly where we do not want to see. Naturally we see a more northern solution with our storm farther down the road. The GEFS and the EPS have also degraded as well. Though with their smoothing it is not as obvious and clear cut as the above example the tendencies I am seeing indicate it is more then likely this same shortwave is the culprit with most of their members as well. The lone exception is that the Euro actually improved as it is seeing less interaction from its prior run with this shortwave in regards to the blocking. Now we are dealing with energy that there is no way the models are going to have a decent handle on at 6+ days. Energy that with just slight adjustments to the east/west/north can mean a big difference to the final outcome (If in fact the models have a decent handle on the blocking). So chances are good we will see swings run to run from a full blown cutter to a transferring low off the VA tidewater or anything in between. For the record, though I can see the possibilities here I put our chances at seeing anything somewhat noteworthy at low odds especially outside the mountains and possibly some of the favored areas. I will consider it a win if we just see some mood flakes in the air at some point. It is only early December after all and there is a good reason we don't typically see much until around Christmas or afterwards. I am just looking at this as a training exercise for all the CONUS transversing bowling balls that we will be tracking this winter. In fact I think I might even pull out my Kocin books and study the many KUs spawned by these bowling balls. Need to know how our KUs this winter compare to prior ones after all.

LOL. Just looked at the 18Z GFS. That baby is oh so close to a legit snow if not even a mauling for the DC/Balt corridor. 6 hour quicker capture of the surface low. A little less separation between the 50/50 and the storm resulting in a little farther south transference of the surface low as the boundary doesn't get dragged up north as quick. Primary gaining less latitude before transferring. Even the model being wrong by 1 or 2 degrees at 850. Any one of these things mean 6+ if not a foot or more. Okay, I am done 'ing. Back to our regular scheduled program... The sky is falling. AO is going positive for the rest of the winter. Big blue balls of death are going to inhabit the pole. SW is going to get dumped into time and time again.

Dec 2nd. The difference between Maybe and Forgetaboutit. Here's the Euro 12z at 180 hrs. Notice the weak heights over top in southern Canada. These are mostly due to energy rotating down towards that region. Not really a good blocking look. Also we are seeing some decent ridging between the 50/50 and the closed low in the central US. This look will not get it done. The storm will cut and cut and cut before we see a transference to its east. If it even decides to do that. Forgetaboutit... Now here's the maybe. Notice we are seeing much stronger heights in southern Canada thus stronger blocking. The energy that was helping to break down these heights on the Euro is skirting to the east instead of dropping southward. The ridging in the East is much weaker and a good portion of that can be attributed to the storm being quicker creating less separation between it and the 50/50. This is allowing for a quicker breakdown of the eastern heights. In this setup the low will cut only so far before it hits a wall and decides to cut to its south and east towards the boundary. The boundary in this setup is much farther south because of the quicker breakdown of the eastern ridging does not allow that to escape to the north as in the other case. MAYBE? This actually isn't such a horrible look, especially the farther north and west you get. That said we are still fighting climo temps to a point so we all know how that goes. Besides 8 days. Plenty of times for us to lose this. eta: We are also seeing the same differences between the GEFS and the EPS. So put your money on the model you trust the most.

Hadn't look at it in a couple of days but last I checked it was promising. Going to hang out in the COD for a little while before exiting into 7, gain amplitude and looking as if it wanted cycle back through the cold phases once again. Of course like the CFS, I have found quite often looking at the COD is just a matter of picking the run you like and hugging it because the run to run consistence could be somewhat shotty.

To tell you the truth I am just happy as crap that we aren't seeing a reload of a massive dump into the west., at least yet. We can work with what we are seeing in the upper latitudes at this time in the extended and it can transition quickly there to favorable setup for us. Not even sure I buy into what it is trying to sell us at this time to boot. But a dump dump in the West screws everything up for an somewhat extended period where we are once again struggling to get a favorable wavelength through the CONUS. God help us if we were to lose the EPO as well as then there is a good chance we see the US and Canada flooded with PAC air where we are spending several weeks trying to right that. I don't even think it is a median. Been following it for awhile now and that doesn't even seem to fit.

Oh go ahead. We already know this board is bipolar.

The Dec 1/2 time frame is starting to get my interest somewhat. At least as much interest as a storm roughly 8 days out can. GFS isn't quite there yet but it is starting to get close and is following the GEFS' lead at this time. It is finally catching onto the idea of blocking over top in Canada that will stop the cutter in its tracks with secondary development to the SE. If this is actually how this plays out it will be highly dependent on where the boundary sets up through our region prior to this redevelopment. Needless to say the farther north and west you are the better your chances.

And this is the look that could potentially put DEC 1-2nd into play for us.

Thanks. Meant to mention that if we saw this look shifted westward where we were riding the front side of the trough it would possibly be a different story.

Several things here that are showing suppression and for the most part a cold dry look. Notice how tightly packed the height lines are in the east and they extend well down into the south? Sure sign of suppression. Not only that but we are sitting at the base of the trough with a strong NW flow moving in (again the tightly packed height lines). Also we are seeing these height lines running parallel to each other from the central US to well off the coast with no sign of convergence. Convergence is what you want to see for precip and storms. If you look out west you will see where the height lines are converging. If you also look at the anomalies they clue you in as well. We are deep in them as they are broad and extended far to our north as well as the deep south. Also see the deepest anomalies through our region and to our NE which is a good sign we are deep into the cold air mass. This is pretty much the look we see after a storm has moved through and we are now seeing the cold, dry air moving in/moved in.

You are going to be one of those GUYS, huh? Rubbing it in. And I hope you know I am just kidding.

Yeah. Not really sure what is up with that. Different algorithm? Would say they are using the median instead of the mean but that doesn't look to jive either.

P15. Saw it too. Not quite sure I am ready to be shoveling 2-3 feet of snow quite yet. Just kidding.

GEFS is really starting to pick up on the DEC 1 possibilities the last few runs. Saw the 18z yesterday evening and thought there might be possibilities and the following runs have been improving on it. ETA: Actually the GEFS is more so centered on the 2nd then the 1'st.

Not so much. It's the time period a couple of days before this that is of some interest. This is pretty much a suppressive look where we are locked in the cold. Can score some NS energy dropping down (clippers) but that would probably pretty much be it.

Just started glancing over this site and just read something and went DUH!!! I had totally forgotten that the GFS and the GEFS are not really the same models. GFS is the new FV3 dynamical core whereas the GEFS won't be upgraded until sometime in 2020. Pretty much gives us a disconnect especially when we get to the longer leads on the forecasts.

YOU THE MAN!!! Thanks. That's the one. Could have sworn I had bookmarked it before. Definitely bookmarked it this time though. Only problem now is, you have probably just added another 15-20 minutes to my morning model routine.

Pretty much what I use the 50 mb for as well though I do like to get an idea of where the warmth is originating as well. If I had my choice though I would rather like to see the 100 mb and especially the 200 mb (where the tropopause is located), think these regions would give you a much clearer idea on the coupling between the strat and trop. Thought @frdhad provided a link to a site for that that I bookmarked but after looking I am guessing not.

Hadn't really been paying too much attention to what we were see upstairs as far as the strat pv the last week or two. Decided to take a glance this morning because it looks as if the 500 mb pv is crossing onto our side of the globe. Pulled these up initially and thought this is pretty good. Applying good pressure to the 10 mb pv at day 3. Then I came across this at day 16. Now I don't know how this rates historically as far as warming but the fact that it is off the scale gives me the impression that this is fairly impressive warmth. Add in the fact that this is centered squarely over the pole with both the warmth and the positive height anomalies and you just know the 10 mb pv is taking a major beating. Not surprisingly if we look at the 10 mb zonal winds (shows strength of pv) through this period of time we are seeing a steep dip with the latest GEFS run within the members. In fact we see several that are actually showing a reversal (black circle). And this is not an aberration as we have seen this on the last day of runs though not quite as extreme. As far as whether the Euro agrees it is hard to say as I have limited access to maps for the strat and they only are available with the op up to 240 hr before we see this occur. I will say though that the precursor to this event is showing up by hour 240. One last comment, this warming is occurring initially at the extreme upper levels of the atmosphere and not warmth propagating upper wards from the lower levels. And if I recall correctly this has far more impact on the pv then the other evolution.

I really won't be sweating the details of anything beyond 10 days at this point myself. Day 10 or so is where we see the 500 mb PV probably begins its migration over the pole onto our side of the globe (looking more and more likely) and where it eventually lands will have a huge impact as far as our weather here in the east. And the details on that are still to be decided especially when I see what is occurring in the strat. As far as I am concerned it is a flip of the coin as to whether we see a reload with a massive dump into the west or we see the arctic express set up for a time or anything in between for that matter. Me being a I favor the cold and possibly snowy scenario. At least until I don't.

If the models (in particular the GEFS which I have looked at closely the last 2 days) is correct with its depiction of the EPO on steroids (strength and extending beyond the pole) through the period and beyond it makes a strong argument that we do see the NAO disappear sometime in the extended. Quite often we will see the pv or a portion forced onto our side of the globe typically getting slotted near or even into the NAO domain and in fact this is what we see with the GEFS. That said, I am not totally sold on seeing that occur (losing the NAO). The models have been under playing or even showing it as non-existent quite often this this short season so far and it would not surprise me whatsoever if this is the case here. Assuming for the moment that the GEFS is somewhat right in regards to the EPO and subsequent pv migration our way, putting a -NAO into the equation adds some interesting possibilities. With a -NAO in place we would probably see the pv forced much farther south into mid or even southern Canada. This EPO and deep dropping pv combo would mean we would see a severe cold outbreak into the central and/or eastern US depending on exactly where it drops. Also I wouldn't even rule out the possibility that the pv itself or an extension of it gets planted into the 50/50 region. Needless to say good things can happen if that were the case. But all of this is pure speculation at this point as I see no indications as of yet that we will in fact have a -NAO at that time.

Interesting the changes we see just after 3 days of runs within the medium range and the repercussions they have further down the line. Below we have a GEFS run from just 3 days ago (day 8). Note that we are seeing the PAC heights occurring off the Aleutians with a +EPO over Alaska. -NAO is present as well as the troughing/weakness in the SW which looks to be mainstay as we have seen over the last few years. We also have ridging running up the East coast in response to this SW troughing. ***Note: with the one feature I am keying on (the PAC heights), prior runs were also showing these heights in the north central Pacific so this one run is not an aberration.*** And this is the temp profile running through the CONUS in response to the above. Nothing earth shattering. Cold anomalies embedded within the SW trough, warm with the ridging in the East. Also see warm anomalies with the increased heights south of the Aleutians as well as cold associated with the +EPO. Now look at the differences we see at 500's on the models just 3 days later (day 5). The PAC heights are now located running up into Alaska as we see the initial development of a -EPO. In response we are seeing the beginnings of a major dump into the SW. We are also not seeing any response with ridging in the east as of yet as we are still early in the process. A stronger version of the -NAO is present and will come into play later. And below we have the response in temps. Notice instead of pedestrian cold in the west from prior we are now seeing a fairly significant cold shot moving down. With the developing EPO we are seeing warmth flow into Alaska as well as a typical signature of a neg NAO with warmth situated over Greenland. Now lets move 2 days (day 7) later from the current run above. A negative EPO has been established and with that flow around the EPO dumping directly into the southwest we are seeing a strong, deep south pushing trough/closed low being established. In response we are seeing very strong ridging popping up in the east. This look alone would have me shutting off my computer for at least the next week as I lie whimpering in my bed. But we have a savior and that is coming from the N Atlantic with a NAO/50/50 combo as it is pushing back against the ridging in the east and will be a key player in forcing the NS southward later on. Now what we will see occur further in the evolution of the pattern depends on both these features existing and being established for a period of time. No 50/50 and that ridging probably pops all the way into the NAO domain which is the last thing we want to see. No -NAO and we don't see the 50/50 get trapped underneath for a period of time. In other words, without a long duration NAO/50/50 combo what we see occurring in the west would quickly degenerate into a horrible look for our chances for the foreseeable future as the western cold would get shunted northward into Canada long before we could even sniff it. Below we have the temps for the above time frame. We have some fairly significant cold into the SW and we see warmth surging northward in the east. Now if you note the cold anomalies in the central/western portion of Canada these are indicative of the push back to the east coast ridging we are seeing from the nao/50/50. Now at day 11 we are seeing this. The NAO and 50/50 have done their magic. They have shifted the NS and accompanying upper latitude trough eastward and southward into the Midwest. This setup is now allowing the western cold to migrate eastward instead of withdrawing northward in the central US which would be the typical response we would see on the initial cold dump being so far westward and south. Of course we are once again seeing the SW weakness (get used to it, I think that feature will be a common one once again). But note at this time we are now losing both the -NAO as well as the 50/50. Now this may or may not be a problem. Now the NS/upper latitude troughing may get established and stay in place in the east. Then again maybe not. Over the last few years there has been an inclination for that feature to migrate back westward when there was no forcing in place to keep it in the east. Thus we would see a reload of a dump into the west (wash/rinse/repeat). But there may be indications that something else may come into play keeping that feature in the east regardless. If you note the pv lobing out into north/central Canada. Think that is a precursor of the 500mb pv migrating unto our side of the globe. This could possibly be the forcing mechanism we are looking for. Below we have the temps for day 11 above. Note that we are seeing a migration of the some fairly significant cold eastward into our region instead of northward into Canada. And we can thank the NAO/50/50. Now though the cold is fairly significant at this time I would not be surprised if we see even deeper departures as this period of time nears. Now finally we have day 16. Note that we still have the -EPO with a +PNA thrown in. Of course the SW weakness is there. But notice that we do in fact see the pv rotating onto our side of the globe with a fairly deep southward push. In response we are also seeing the upper-latitude trough/NS stay planted in the east. And we can see temps at this point are CONUS wide. Again, I think we would probably see stronger departures if the GEFS is somewhat accurate with the 500's. Just a quick comment on what we see occur with the pv. The pv at this time is currently sitting on the other side of the globe. What initiates it's migration across the pole is probably mostly due to the strong and long duration EPO that we see develop at day 5. At day 16 we still see it and it extends it beyond the pole. This is providing the forcing on the pv to move. I know I went over many of these things on my previous post but I think it is kind of important we keep an eye on the next week or two as I think what we see in regards to the models and what actually verifies will be a good indication of what to expect this winter excepting a major pattern change. We will more then likely see the same tendencies and bias within the models over the course of the winter and should also get a good idea how these different features will interact when it comes to real life weather and not model land. One last thing. Much of what I have posted above is in regards to what the GEFS is showing us and not so much predictions on my part especially later in the run. At this time I am very confident we do see a major cold snap drive deep into the SW. I am almost as confident we see that push eastward eventually reaching our region with at least a fairly significant initial cold shot instead of retreating northward into Canada. Questions arise quite quickly afterwards though as we lose both the NAO and 50/50 and their forcings on the NS (If in fact we lose them). Assuming the -EPO is a feature we will see for the duration (we lose the epo in the longer ranges and all bets are off) the major question then becomes where does the NS dip southward? It stays in the east whether from forcings or on its own then we are most likely looking at a long cold spell well beyond the end of the extended (well below temps first half of winter). If that migrates back westward then there is a good chance we are looking at a major warm up after a brief cold interlude as the EPO once again dumps deep into the SW before something forces the NS easterly again. So basically, anything beyond day 11 I am looking at with quite a bit of skepticism. Could be a matter of one run to another where we go from heavy winter gear to pulling out the shorts. ****Ignore this pic below. It won't let me get rid of it.********