GreyHat Posted January 19 Share Posted January 19 Currently NWS forecast for this storm for Magnolia Delaware Saturday A chance of snow. Partly sunny, with a high near 23. Chance of precipitation is 30%. Saturday Night A chance of snow. Mostly cloudy, with a low around 9. Chance of precipitation is 30%. Sunday A chance of snow. Partly sunny, with a high near 21. Chance of precipitation is 40%. Link to comment Share on other sites More sharing options...
Ji Posted January 19 Share Posted January 19 Stolen from the southern forum. Just out to 144, of courseUuuugh Link to comment Share on other sites More sharing options...
mitchnick Posted January 19 Share Posted January 19 3 minutes ago, Maestrobjwa said: Stolen from the southern forum. Just out to 144, of course I know, that's why I posted. It shifted south. 2 Link to comment Share on other sites More sharing options...
Ephesians2 Posted January 19 Share Posted January 19 37 minutes ago, GreyHat said: Would a stronger L like 991 push noth? Disclaimer: I'm not the expert at upper level analysis by any means [Edited to remove a sentence that demonstrated that fact] But this doesn't look quite like the "HECS" look that supports a low that strong though its a very good pattern This is -EPO, -NAO, with a neutral looking PNA with the ridge offshore. The -EPO delivers arctic air while the -NAO stops the storm from cutting NW. This looks like it would support, at the upper potential, an overrunning event like Jan 2010 or... Dec 2018 (you all would love that if it had been 100 miles north) with widespread double digits totals, but not the 18-24"+ totals that would be "historic". Link to comment Share on other sites More sharing options...
GreyHat Posted January 19 Share Posted January 19 2 minutes ago, Ephesians2 said: Disclaimer: I'm not the expert at upper level analysis by any means But this doesn't look quite like the "HECS" look that supports a low that strong though its a very good pattern This is -EPO, -NAO, with a neutral looking PNA with the ridge offshore. The -EPO delivers arctic air while the -NAO stops the storm from cutting NW. But for a truly historic storm it would seem like we'd need the ridge a few hundred miles east which would push the trough southeast over the TN valley and phase with the subtropical energy and create a stronger storm. This looks like it would support, at the upper potential, an overrunning event like Jan 2010 or... Dec 2018 (you all would love that if it had been 100 miles north) with widespread double digits totals, but not the 18-24"+ totals that would be "historic". Thanks, here to observe and learn, the days of doorman, PSU and others from the different forms was always a great reading. Link to comment Share on other sites More sharing options...
Maestrobjwa Posted January 19 Share Posted January 19 4 minutes ago, mitchnick said: I know, that's why I posted. It shifted south. Oh my bad I was looking at the gifs in the wrong order, lol Darn it Link to comment Share on other sites More sharing options...
bncho Posted January 19 Share Posted January 19 1 minute ago, GreyHat said: Thanks, here to observe and learn, the days of doorman, PSU and others from the different forms was always a great reading. Well IMO he's partially right, the -NAO obviously helps but it's mainly because a 1050 high squashes everything Link to comment Share on other sites More sharing options...
NorthArlington101 Posted January 19 Share Posted January 19 one step closer to purple than we usually get 9 1 Link to comment Share on other sites More sharing options...
aldie 22 Posted January 19 Share Posted January 19 12 minutes ago, Maestrobjwa said: Stolen from the southern forum. Just out to 144, of course Hey at least we have AL's models on our side Link to comment Share on other sites More sharing options...
Maestrobjwa Posted January 19 Share Posted January 19 3 minutes ago, aldie 22 said: Hey at least we have AL's models on our side Yeah I'm having a hard time believing those, tbh. Until we see less suppression from the regulars it'll be hard to buy it 2 Link to comment Share on other sites More sharing options...
Terpeast Posted January 19 Share Posted January 19 Just woke up. I’ll summarize… models basically held. We’re on the northern part of the precip shield, which could help our ratios and h700 fgen forcing. Cold high is starting to weaken (was probably overdone). And I’ll address this: 9 minutes ago, Ephesians2 said: Disclaimer: I'm not the expert at upper level analysis by any means But this doesn't look quite like the "HECS" look that supports a low that strong though its a very good pattern This is -EPO, -NAO, with a neutral looking PNA with the ridge offshore. The -EPO delivers arctic air while the -NAO stops the storm from cutting NW. But for a truly historic storm it would seem like we'd need the ridge a few hundred miles east which would push the trough southeast over the TN valley and phase with the subtropical energy and create a stronger storm. This looks like it would support, at the upper potential, an overrunning event like Jan 2010 or... Dec 2018 (you all would love that if it had been 100 miles north) with widespread double digits totals, but not the 18-24"+ totals that would be "historic". in this specific case, move that pna ridge a few hundred miles east, and we’ll suppress this thing all the way to the gulf. The EPO is so strong that we need a little SE ridging to give us a good overrunning event. It’s not the same thing as a bomb cyclone HECS, but overrunning with lots of cold can produce a lot of snow if strong enough. 13 2 Link to comment Share on other sites More sharing options...
SnowenOutThere Posted January 19 Share Posted January 19 KEY MESSAGE 2...The potential for a possibly significant winter storm has increased for this weekend, but uncertainty remains. The upper air pattern resembles what appears to be a very favorable pattern for a winter storm somewhere in the eastern U.S. heading into this weekend. Before that, a potent cold front pushes through the region late Thursday into Friday, followed by a reinforcing Arctic front late Friday into Saturday. This will lead to increasingly cold conditions each day from Thursday through the entire weekend. Well below average temperatures are forecast, especially by Sunday. In addition, some upslope snow showers are possible with each front. By the end of the week and especially heading into the weekend, the upper-level pattern becomes quite active in both the northern and southern branches of the jet stream. Model guidance is still very much all over the place in regards to exactly what comes of this, but there is growing consensus for an area of low pressure developing across the south-central/southeastern CONUS. Depending on when and where that area of low pressure develops, as well as where it goes after it does develop, there could be significant wintry precipitation across our area sometime next weekend. Uncertainty remains with this system, as there is some potential that strong Arctic high pressure could suppress the system south. However, that high (~1040 mb Arctic high) is also a source of very cold air; this likely remains in place due to a favorable -AO/-NAO blocking pattern. Meanwhile, there are an increasing amount of ensemble members that bring significant wintry precipitation to the region due to an amplified southern stream influence - something we have seen very little of so far this winter (typical of La Nina). The low may not escape as easily out to sea given the -NAO block. The nearby steady source of very cold air and the amplified southern stream occurring in tandem are what raise some red flags for significant wintry precipitation potential this weekend. The latest ensemble guidance is certainly on the upward trend in that regard, but that doesn`t mean it can`t swing back in the other direction. It will be key to monitor this threat closely in the coming days as the different parts of the system become better sampled by surface and upper air obs. Current model spread indicates an axis of significant snow/ice could be as far north as Upstate New York, or as far south as the Carolinas. Bolded some key parts of the afd 1 Link to comment Share on other sites More sharing options...
aldie 22 Posted January 19 Share Posted January 19 14 minutes ago, Ji said: Uuuugh You're going to have a long week....If i were you i would be very vague in your FB posts and really vague for your paying customers lol 3 1 Link to comment Share on other sites More sharing options...
SnowenOutThere Posted January 19 Share Posted January 19 1 minute ago, Terpeast said: Just woke up. I’ll summarize… models basically held. We’re on the northern part of the precip shield, which could help our ratios and h700 fgen forcing. Cold high is starting to weaken (was probably overdone). And I’ll address this: in this specific case, move that pna ridge a few hundred miles east, and we’ll suppress this thing all the way to the gulf. The EPO is so strong that we need a little SE ridging to give us a good overrunning event. It’s not the same thing as a bomb cyclone HECS, but overrunning with lots of cold can produce a lot of snow if strong enough. My thinking is similar to yours. Personally I think we’re in a pretty good spot as of now considering that the AI GFS/Ukmet are almost too far north. Main thing I want to see out of today is the Euro and Euro ai to hold and have the CMC and GFS come closer to that solution. I think the way we get that is have the pv to our northeast be a bit less intense or (better yet though less likely) have a stronger low. That said, I wouldn’t want models to all suddenly jump way north today but just show increasing confidence a total miss to the south is unlikely. 2 1 Link to comment Share on other sites More sharing options...
mitchnick Posted January 19 Share Posted January 19 5 minutes ago, aldie 22 said: You're going to have a long week....If i were you i would be very vague in your FB posts and really vague for your paying customers lol He better, or he'll have to give his wife and kids back their money. 4 Link to comment Share on other sites More sharing options...
bncho Posted January 19 Share Posted January 19 FWIW, the Euro AI was almost dead on at D5. It took the Euro longer to get there for yesterday's event. Tonight's runs will be 5 days out. If the Euro AI continues to show similar solutions I see very little reason why not to believe it. 7 Link to comment Share on other sites More sharing options...
WxUSAF Posted January 19 Share Posted January 19 4 minutes ago, bncho said: FWIW, the Euro AI was almost dead on at D5. It took the Euro longer to get there for yesterday's event. Tonight's runs will be 5 days out. If the Euro AI continues to show similar solutions I see very little reason why not to believe it. The one caveat, which is hard to evaluate, is whether the high pressure (and associated upper level configuration) will be so anomalous, that the AI will, by its nature, not predict it. The AI models are trained on some amount of reanalysis, and so they can't/won't predict extreme or record-breaking events well. Will this setup be record-breaking? Hard to say. But that's something to keep in mind when evaluating the AI models vs the physics-based models. 8 9 Link to comment Share on other sites More sharing options...
aldie 22 Posted January 19 Share Posted January 19 3 minutes ago, WxUSAF said: The one caveat, which is hard to evaluate, is whether the high pressure (and associated upper level configuration) will be so anomalous, that the AI will, by its nature, not predict it. The AI models are trained on some amount of reanalysis, and so they can't/won't predict extreme or record-breaking events well. Will this setup be record-breaking? Hard to say. But that's something to keep in mind when evaluating the AI models vs the physics-based models. I desperately want to hang my hat on the fact that extreme record-breaking events are just that. We will know soon enough i suppose Link to comment Share on other sites More sharing options...
Eskimo Joe Posted January 19 Share Posted January 19 Phase 8 Neg AO Neg NAO Positive PNA 12 1 Link to comment Share on other sites More sharing options...
Conway7305 Posted January 19 Share Posted January 19 Can anyone post the Euro AI Ensembles? Link to comment Share on other sites More sharing options...
Maestrobjwa Posted January 19 Share Posted January 19 5 minutes ago, Eskimo Joe said: Phase 8 Neg AO Neg NAO Positive PNA You'd think! A fail would just be bad luck i.e. a random anomalous high at the wrong time. But hopefully not! Link to comment Share on other sites More sharing options...
Eskimo Joe Posted January 19 Share Posted January 19 Thursday looks like the only "warm" day and that's upper 30s/low 40s. The rest of the week looks primed to keep the ground cold. High in the 30s, lows in the mid 20s. Link to comment Share on other sites More sharing options...
bncho Posted January 19 Share Posted January 19 There are two possible outcomes for this event: 1. A major ice storm affects southern CAD zones, and DC and points north get a major snowstorm. (Euro AI, UKMET, GFS AI, Euro) 2. A major snowstorm affects southern CAD zones, and DC and points north receive little to nothing. (GFS, CMC) What do we know of each model? The Euro AI is often locked onto an event inside D5 and is often deadly inside that range, but can be locked onto an incorrect solution, only to fold 48 hours before the event (credit to @high risk). It also often has a QPF bias. The Euro often tends to overamp low pressure systems, but it also tends to hold back energy in the Baja. It also often has a QPF bias. The GFS tends to show more suppressive, progressive solutions, and often tends to verify NW. The CMC has a major cold bias, and tends to overdo Arctic HPs. It also, generally, has a suppressive bias, but it is less prominent than the GFS. The UKMET tends to struggle on thermals, often being too warm. It also tends to overamp systems. Since the GFS AI is new, I don't know much about it. Although more operational models (that I'm aware of; I have no idea what Google's model outputs) support the northern solution, ensembles have been trending colder and snowier towards the southern solution over the last 24-36 hours. This is why I am skeptical to declare victory for the northern solution just yet. It would be easy to go with the Euro AI, just because that has been the best performing operational this winter inside D5. However, a major caveat to this is that the upcoming HP may be so anomalous that it hasn't received enough training data to output the correct solution, just due to its inexperience (credit to @WxUSAF). This should be a good test for the AI Euro. Now, it's too early to declare anything, but I am leaning towards the northern solution. 1050 HPs are extremely rare and often overdone in setups like these (credit @Terpeast), and I don't think it'll be able to suppress it enough. However, if a ultra-strong HP does pan out, the Euro AI may have a greater probability of being wrong. Stay tuned... 4 Link to comment Share on other sites More sharing options...
mitchnick Posted January 19 Share Posted January 19 6 minutes ago, Conway7305 said: Can anyone post the Euro AI Ensembles? I don't have snowfall maps, but here is the total qpf for the event. 3 Link to comment Share on other sites More sharing options...
mitchnick Posted January 19 Share Posted January 19 Just now, mitchnick said: I don't have snowfall maps, but here is the total qpf for the event. Closeup 2 2 Link to comment Share on other sites More sharing options...
bncho Posted January 19 Share Posted January 19 8 minutes ago, Conway7305 said: Can anyone post the Euro AI Ensembles? I'm too young to be looking at porn... 1 1 8 Link to comment Share on other sites More sharing options...
CAPE Posted January 19 Share Posted January 19 The 0z and 6z Euro Ens essentially look the same wrt precip/snowfall at 6z on Sunday, outside of run to run noise. There is no 'trend'. I am going to trust the Euro more overall for this potential event given how crappy the GFS has performed recently. I will lump the AI models in with the GFS/GEFS based on their performance with our recent (mostly Non) event. 4 1 Link to comment Share on other sites More sharing options...
Terpeast Posted January 19 Share Posted January 19 1 minute ago, CAPE said: The 0z and 6z Euro Ens essentially look the same wrt precip/snowfall at 6z on Sunday, outside of run to run noise. There is no 'trend' I am going to trust the Euro move overall for this potential event given how crappy the GFS has performed recently. I will lump the AI models in with the GFS/GEFS based on their performance with our recent (mostly Non) event. The MSL pressure field actually shifted north in the TVA on 6z vs 0z eps. Mostly noise, but the shift was noticeable. 3 Link to comment Share on other sites More sharing options...
NorthArlington101 Posted January 19 Share Posted January 19 FWIW - the new Canadian (I think it replaces the old in the spring) is light snow -> sleet -> little bit of FRZA. So it’s amped and totally different than the about-to-be-replaced version Link to comment Share on other sites More sharing options...
EastCoast NPZ Posted January 19 Share Posted January 19 I am going to look at the last 10 years of results and congratulate the fine people of VA Beach on another snow storm. Weenie me. 2 1 1 Link to comment Share on other sites More sharing options...
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