MAG5035 Posted January 3, 2021 Author Share Posted January 3, 2021 Still not totally sure what to make of today's system. Looks like two different waves of precipitation. Surface temps have cooled off nicely overnight and most areas near or below freezing. However, temps per mesoanalysis at the 925mb (southern third of the state) and 850mb level (most of the state) still above freezing. This means the initial wave of precip arriving later this morning likely to be a mix, which is the main basis of the advisory for the Sus Valley (for the possibility of a T of ice). The second and probably main wave of precip arrives in the afternoon associated with the upper level low itself. Under this is where we have the cooling at 925 and 850 to support an all snow column. Track of the weak mid level low features seem a tad NW to me, thus I kind of support CTP having the best snows from UNV on to the NE instead of LSV locations like MDT. This could cover more of the central counties depending on how precip develops though. Near term guidance has generally been putting the best QPF from the upper level low from the central counties to NE PA. Dare I say Williamsport appears to be the new snowtown these days haha. 2 Link to comment Share on other sites More sharing options...
Mshaffer526 Posted January 3, 2021 Share Posted January 3, 2021 Glancing out at my porch in Gap, looks like a little bit of accretion. Some kind of mix now, looks like a bit of everything Link to comment Share on other sites More sharing options...
Mshaffer526 Posted January 3, 2021 Share Posted January 3, 2021 Precip has changed from a sleet/ZR/snow mix to what seems to be all snow as it wraps up. Ground has whitened up nicely, especially on mulch. Unexpected little surprise. Appreciate the little things! 1 Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 5 hours ago, MAG5035 said: Still not totally sure what to make of today's system. Looks like two different waves of precipitation. Surface temps have cooled off nicely overnight and most areas near or below freezing. However, temps per mesoanalysis at the 925mb (southern third of the state) and 850mb level (most of the state) still above freezing. This means the initial wave of precip arriving later this morning likely to be a mix, which is the main basis of the advisory for the Sus Valley (for the possibility of a T of ice). The second and probably main wave of precip arrives in the afternoon associated with the upper level low itself. Under this is where we have the cooling at 925 and 850 to support an all snow column. Track of the weak mid level low features seem a tad NW to me, thus I kind of support CTP having the best snows from UNV on to the NE instead of LSV locations like MDT. This could cover more of the central counties depending on how precip develops though. Near term guidance has generally been putting the best QPF from the upper level low from the central counties to NE PA. Dare I say Williamsport appears to be the new snowtown these days haha. Here is the latest HRRR for this afternoon. It will be interesting to see how it plays out. Parts of Lancaster & eastern LSV had a dusting of snow this morning, so who knows what type of precip we will get this afternoon with the second wave? It is a very borderline minor event, but hopefully some more of us can put a little snow on the board later on. Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 @MAG5035 the HRRR agrees with you that Williamsport is the new CTP jackpotville! Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 @MAG5035 Reading over the Philly thread, places near Chester county and even closer to Philly got up to an inch of snow this morning. Do you think the column will be cool enough for more snow later with the second wave if precip rates are good even in the LSV? Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 Also, did anyone else see the multiple chances from the 0z GFS that I posted last night?!?! This place should be getting busy tracking this week with this advertised blocking pattern! It is just a matter of time before it delivers the snow goods to us! Link to comment Share on other sites More sharing options...
Itstrainingtime Posted January 3, 2021 Share Posted January 3, 2021 1 hour ago, Mshaffer526 said: Precip has changed from a sleet/ZR/snow mix to what seems to be all snow as it wraps up. Ground has whitened up nicely, especially on mulch. Unexpected little surprise. Appreciate the little things! Had a nice period of sleet here, but no snow. Good for you! 1 Link to comment Share on other sites More sharing options...
showmethesnow Posted January 3, 2021 Share Posted January 3, 2021 I spent a couple of hours yesterday morning writing up a post on the potential centered around the Jan 8th time frame. Unfortunately just before I went to post it I lost everything. Needless to say my puppies ran for cover and my wife scolded me for my ranting and foul language with yet another lecture on how I needed to save my work continuously. So, just another typical day for me. But I am here to try again. Fingers crossed. And yep, I will be saving my work continuously. I am going to use some maps I had drawn up yesterday. The general setup that intrigued me almost a week ago, a 50/50 getting locked in under a block for an extended period of time, has not changed whatsoever. This general setup argued that this was a period of interest for storminess in the east. But as we have neared in time and some finer details have emerged I have become much more interested. Below we have the general setup with a -NAO and 50/50 combo. What this does is back the flow upstream through the CONUS creating amplification with both ridging and troughing where it sets up a favorable track for energy moving eastward through the CONUS. Below we see this, as energy that entered the PAC northwest a couple days previously has moved eastward and taken a big drop southward with the amplifying trough into the Mississippi basin. Given the blocking in front of this system, this is actually positioned well for its move into the east. Now a further detail has emerged in the last few days that has has only increased my interest in this period. But before I go into that I want to mention something else. Some of our bigger storms are associated with the breakdown of a -NAO (senility is kicking in so the term escapes me at this time). What happens is that all the pressure created upstream from the -NAO/ 50/50 block is released as the flow in front of an incoming system quickly relaxes when the blocking breaks down. And like pulling a cork on a champagne bottle we see an explosive response, in this case a rapidly intensifying storm that will typically pull northward. A big part of this explosive response is actually associated with what we see occur with the 50/50 during this breakdown. The 50/50 plays a huge part in creating the backing of the flow. Take that feature out, as we see when it gets released during a breakdown of the blocking, and the pattern can relax quite rapidly. That said, back to the reason I brought this up. What the models have been keying on these last few days is that we will see a breakdown of this 50/50 through weakening and it withdrawing poleward. This is occurring generally in a favorable time period to impact our potential storm in the east. But with this evolution of the 50/50 we will see a slower relaxing of the flow. So instead of just releasing all the pressure at once as in the above example, the pressure will be released in a slower manner. What this should result in, is a system that will intensify somewhat rapidly and pull northward to a degree during this intensification before it meets resistance from the blocking that still exists. Now where the storm track in the east occurs will probably be dependent on when we actually see the breakdown of the 50/50 occur. Earlier and we probably see the storm track shifted north as the suppression to its east relaxes somewhat. This not only puts into play those areas to the north of the low as it tracks eastward but also potentially coastal areas even farther north somewhat as it intensifies and makes a move northward for a time. If we see the breakdown later in the process we will see this track shifted southward as the suppression in front continues. In this case the intensification and move northward will occur later in the process, more then likely OTS (out to sea). We have seen both scenarios above play out (and solutions in between) on the various operational runs the last few days. The northern extent being through the mid-Atlantic (roughly MD). with some impacts on the coastal regions farther north. As well as the southern sliders that are impacting in the southern mid-Atlantic all the way into N Carolina, with no play on the coastal regions to the north as the intensification and northward pull are occurring OTS. Though there are quite a few things I have been keeping an eye on there are a couple of things I have been keying on and that is what we are seeing with the influence of the 50/50 on the flow as well as any possible ridging between that 50/50 and our developing storm. Below we have an example of a southern slider. Now the influence from the 50/50 low will be determined by placement, how quickly it is withdrawing and track as well as the strength and how quickly it is weakening. That is a lot to factor in. So though it is somewhat crude I find the easiest way to determine the influence it is exerting is to look at the strength of the low pressure anomalies showing up to the south of the 50/50 as well as their placement. The stronger those anomalies, the stronger the suppression we will typically see in the east. Also the placement of those anomalies (east/west) in relation to the incoming trough will generally give you a feel of what to expect as far as any possible ridging that develops between these two features. First off, we note there is very little ridging showing up between the 50/50 and the incoming trough, which we do want to see. This would quite often imply that the trough and the 50/50's influence are too close/far to each other to allow/create height builds. But in this case I think the distance between the two features is fine so I don't think that is the reason for the lack of ridging. I think we have to look elsewhere. That elsewhere is in part, where we are actually seeing the physical representation of the 50/50 at this time which is suppressing the flow overtop. And in part, the stronger suppression in front of the system. One last thing, let's look at the 3 red lines I have drawn as I will use them as comparison in the follow up map. These lines give you a general idea of flow in the east and off the coast and thus the general track of any system. What we see here is not one we want to see as it is a suppressed and progressive look. This following map is a more northern solution of this system and actually not far from a winning one. I want you to compare this to what we see above. If we note the anomalies located to the south of the 50/50 they are coming in weaker. These weaker anomalies imply less suppression in front of the incoming system. We also are still seeing good separation between the incoming trough and the 50/50's influence though they have adjusted to the east a touch. I would also like to point out that the physical representation of the 50/50 has shifted east as well and along with it the suppression it was creating overtop. So let's look at what we have when we relax the suppression overtop and to the east and have good separation between the 50/50 and the incoming trough. If you look at the 3 red lines, that are comparable to the above map, we are in fact seeing ridging developing. We are also seeing an adjustment north as the suppression in front is relaxing. These lines also suggest that we would see a tucking in of a surface low to the coast as it amplifies and makes a northward jog for a time before it gets shunted out to sea. This is a much better look then the one above and not far from being a winning one for portions of the mid-Atlantic and up the coast somewhat. So what are my general thoughts on this system? I believe we do see a storm in the East. I also like the models having pretty much set up goal posts at this time from NC and OTS, up to MD and portions of the shores to the north. Both these options and ones between are still very much on the table given the setup. That said, I myself favor the northern solutions at this time. In fact, I would not be surprised if we actually see a solution that comes in slightly north of the northern goal post. I know some will fret the temps. But if we see the northern solutions play out I think many would find the temps would break favorably for various reasons, especially those west of the Fall line (95 corridor). I do want to throw one word of caution in here as well. There is one possible fly in the ointment. The GFS has suggested this possibility at times and the overnight Euro just threw it up as well. What I want you to focus on is the energy that is dropping down in the NS overtop the energy running to the south. What is happening is that the models are seeing a split in the energy when it enters the PAC NW. A piece is dropping southward and a piece is running through Canada. How the models handle that northern piece is crucial. If the models start keying on dropping that feature south of the Canada border then it is more then likely game over as there are very few good solutions that could come from that. What we would more then likely see is unfavorable suppression and/or a kicker that boots our developing system out. Either way we see a system that is too far south and is very progressive allowing no time for amplification. 2 Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 @Itstrainingtime @pasnownut What are your thoughts on the upcoming storm chances later this week & next week? Link to comment Share on other sites More sharing options...
showmethesnow Posted January 3, 2021 Share Posted January 3, 2021 Just now, Blizzard of 93 said: @Itstrainingtime & @showmethesnow What are your thoughts on the upcoming storm chances later this week & next week? Just posted my thoughts on the Friday potential above. As far as the follow up there is potential there as well but what we see Friday will probably play a big part in that. Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 4 minutes ago, showmethesnow said: Just posted my thoughts on the Friday potential above. As far as the follow up there is potential there as well but what we see Friday will probably play a big part in that. Great, thanks! The next few weeks should be our best pattern potential that we have had in years! It’s just a matter of when & how many storms deliver! I am fired up! Link to comment Share on other sites More sharing options...
showmethesnow Posted January 3, 2021 Share Posted January 3, 2021 15 minutes ago, Blizzard of 93 said: Great, thanks! The next few weeks should be our best pattern potential that we have had in years! It’s just a matter of when & how many storms deliver! I am fired up! Though there are those that would argue this and call it sacrilege, I find a down and dirty way of getting idea if the pattern being represented out in time is favorable is to see what the snowfall maps have to show us. What I am seeing on the ensembles is quite encouraging as we are seeing a notable uptick in projected snowfall as well as an every increasing number of heavy hitters. I expect to see this given the very favorable pattern, and the fact we are seeing this on the models as well only bolsters my thoughts. Now this is not to say that the models are correct in their projections on the pattern in the extended. Just that they are seeing the potential if such a pattern in fact materializes. Link to comment Share on other sites More sharing options...
Itstrainingtime Posted January 3, 2021 Share Posted January 3, 2021 46 minutes ago, Blizzard of 93 said: @Itstrainingtime @pasnownut What are your thoughts on the upcoming storm chances later this week & next week? I'm casually interested. Right now I'm concerned about both temps and the track. If we can get some northern stream energy to phase in south of our latitude, it's game on. I'm just not convinced that happens, and without it we'll be dealing with either a suppressed system, a warm one, or both. Link to comment Share on other sites More sharing options...
Itstrainingtime Posted January 3, 2021 Share Posted January 3, 2021 @showmethesnow great post this morning. Well thought and laid out in a way that is easy to understand. I guess we differ on thought regarding the northern stream impulse- you are correct in saying that it could kill this for us, which is why I said it would need to dig under and phase in. Otherwise, it's game over. 1 Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 9 minutes ago, Itstrainingtime said: @showmethesnow great post this morning. Well thought and laid out in a way that is easy to understand. I guess we differ on thought regarding the northern stream impulse- you are correct in saying that it could kill this for us, which is why I said it would need to dig under and phase in. Otherwise, it's game over. Either way, this is an early chance in the new blocking pattern. If we at first don’t succeed with this one, there should be more chances in the not too distant future. This pattern seems to be locked in for a few weeks at least. Link to comment Share on other sites More sharing options...
kerplunk Posted January 3, 2021 Share Posted January 3, 2021 This would be welcomed: Area Forecast Discussion National Weather Service State College PA 1045 AM EST Sun Jan 3 2021 .NEAR TERM /THROUGH TONIGHT/... Latest NBM and WPC guidance support most likely snow amounts ranging from 1-2 inches across much of central and northern Pa, with 2-4 over the higher terrain just north of I-80. However, there is a decent amount of spread among HREF members, with some hinting at the possibility of briefly heavy snow rates between 20Z-24Z in the corridor from around KUNV to KIPT. Although not likely, this scenario could result in a couple more inches than anticipated in this area. Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 The latest HRRR still a snow chance in the LSV later today from Harrisburg area to the west & north. The coastal is developing well off to the southeast and exiting to the east. It the rates are decent, this might have the chance to verify. Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 The 12z Canadian & ICON are on board with CTP & Harrisburg snow today. Not the best models, but I’ll take it! Link to comment Share on other sites More sharing options...
MAG5035 Posted January 3, 2021 Author Share Posted January 3, 2021 Mostly sleet falling currently after a bit of a damp start to this. Had a glaze of ice on the car first thing this morning. Now to see if this gets to snow quick enough so it can do something accumulation wise. Link to comment Share on other sites More sharing options...
MAG5035 Posted January 3, 2021 Author Share Posted January 3, 2021 Transitioning over to snow now. Link to comment Share on other sites More sharing options...
paweather Posted January 3, 2021 Share Posted January 3, 2021 Sleeting here. Link to comment Share on other sites More sharing options...
canderson Posted January 3, 2021 Share Posted January 3, 2021 Been pouring sleet for about 30 minutes. Link to comment Share on other sites More sharing options...
2001kx Posted January 3, 2021 Share Posted January 3, 2021 Heavy snow here Link to comment Share on other sites More sharing options...
MAG5035 Posted January 3, 2021 Author Share Posted January 3, 2021 1 minute ago, 2001kx said: Heavy snow here Same here, it didn't take long to start accumulating (on the roads too). Link to comment Share on other sites More sharing options...
kerplunk Posted January 3, 2021 Share Posted January 3, 2021 Huge half/dollar sized flakes here. Link to comment Share on other sites More sharing options...
Cashtown_Coop Posted January 3, 2021 Share Posted January 3, 2021 Sleet 32 Link to comment Share on other sites More sharing options...
Blizzard of 93 Posted January 3, 2021 Share Posted January 3, 2021 Snow & sleet here in Marysville have a car top covering. Interested to see what the heavy band of precip will bring in the next few hours! Link to comment Share on other sites More sharing options...
paweather Posted January 3, 2021 Share Posted January 3, 2021 Heavier bands to our west hope with even better rates we turn to all snow. Link to comment Share on other sites More sharing options...
Itstrainingtime Posted January 3, 2021 Share Posted January 3, 2021 Rain. 35 and dark, dank, dreary, drippy, and damp. Link to comment Share on other sites More sharing options...
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