psuhoffman

I knew I had seen the look at the end of the EPS before... EPS March 4 2015 Feb 2 1996 Right before 2 warning level events...there are other examples but those 2 stuck out in my memory from a similar pattern. Both were similar, progressive waves along the boundary. That look can work.

It's probably unlikely...12z on the whole trended the wrong way. But since the critical feature now is a northern stream one that does make me a little more hesitant to close the door since even King Euro struggles with the exact details on those. The STJ on its own isn't going to get it done though... not enough is ejecting and there is way too much going on on top of it...so the key is does the NS dig enough to phase and pull it up. The euro gets the NS shortwave out ahead and so it squashes it. It's all about timing and how much the NS digs...and I would definitely trust the euro along with ensembles over the GEM/GFS ops with that...but its a tricky enough thing that I am not totally 100 percent putting it to bed. But I am only keeping one eye on it...very much interested in the period after.

Gefs walked back from the ledge day 16 too. Clear step towards the eps idea of where the pattern goes in mid February. Again not perfect but a pattern we can snow with a little luck. At least cold would be in the conus.

People who want clarity with things past 5 days will be disappointed but the big picture is the pattern looks less hostile in early Feb and we’re starting to get some random op runs and scattering of ensemble members with hits. That doesn’t suddenly mean I’m gonna forget the seasonal trend or lose my skepticism but it’s hard not to think we at least have more of a chance the next 2 weeks that we have at anytime this winter. Again low bar and all.

Their advancement is outpacing ours. Wish that only applied to NWP.

You can tell all the heavy snow SW of DC is in elevated regions. Then there is that band that starts near DC northeast. Just from that I can deduce that the system phases and the deform starts to crank from there northeast. Gfs and gem shared one commonality. They were both slightly late on the phase to really bomb our area. But that’s not that uncommon. Unfortunately in many other setups we can get a 4-8” storm in its formative stages while Philly northeast gets 10”+. But with the temp issues this time the cutoff between lot of snow and nothing could be less forgiving. That is just one of many obstacles but 12z has been kind so far.

I love it when we have to be confused about “which storm” a post is about. That’s at least a sign things are improving

Depends what you mean. The most probable outcome is no snow. Way more still has to go right than wrong. And if we do get snow the most likely outcome is minor accumulation due to either temp issues cutting down accumulation or some issue like an unclean phase scenario cutting down QPF. But if you’re asking if it’s hypotheticall possible to get a big snow...yea it’s possible. Rare. But there have been rare examples of similar thermally challenges setups where everything went perfect and Baltimore got like 8” of snow. Kind of like when an average weekend golfer lines up for some 175 yard approach shot. What are the odds that shot goes exactly how he envisions it and ends up right next to the hole? I wouldn’t put money on it but every once in a while...

Too early to know how it ends but the gem took a major step in the right direction at h5. Way less of a NS squash fest and more STJ involved.

FRINGED!!! its happening

The phase was slightly late. The ccb deform doesn’t really get cranking because of that. It’s being pinched on its NW side by the unclean phase going on between the NS and SS systems. It was close to big though.

This gfs run was even closer to the unicorn scenario @showmethesnow Highlighted this morning. Oh so close. You can see here the NS phases in slightly late. You can see the initial STJ wave out ahead there with the main NS dining into VA. If that had been a slightly cleaner capture we get that 980 low tucked in more are it’s the unicorn big snow scenario. Temps would have been “ok” on this run we needed a slightly better phase and tucked solution to turn it into a big one. That scenario is still low probability. So much has to go right. But the gfs op almost pulled it off so that probably means the idea isn’t totally dead.

I apply my philosophy for Eagles games to long range model runs. You’re never as good as you think after a win and never as bad as you think after a loss. Unless you’re a Redskins fan. Then you are as bad as you think.

Yea...no real reason for it...it’s nearly an identical run to 6z in the progression of all the various waves. Impressively so for the complexity of this setup. But it simply adjusted the thermal profile a few degrees colder. At that range that isn’t rare.

Gfs seems more amplified than the icon early on. Slower too. Of course we might need slower now. Without the NS phase it’s likely to be too weak to work with all the shortwaves knocking down heights on top of it. A fast moving weak stj wave ends up like the icon. Of course the slow phase bring temp issues. So would you prefer the rock or the hard place?

Fog fail

The simple idea might be a lost cause now. You only have to go out 72 hours to see all the various shortwaves clearly. They are real. And all over the place. And that probably means without a phase nothing can amplify enough. Too much splitting and competition of the energy. Even if it made it here a weak strung out wave won’t work. So were left rooting for a phased bomb now as the only option. Good luck with that both getting it and figuring out all those shortwaves at range.

Excellent point. In a better year when we aren’t always looking at day 10 ghosts by the time one threat either fizzles or is over the next one we turn our attention too is only 5 days out. We don’t even notice the day 7+ shenanigans. Plus 10-20 years ago we didn’t tend to look that far out. 20 years ago nothing even went that far. When I started analyzing guidance in the late 90s at PSU the MRF/AVN (what became the GFS) ran to 10 days at 0z and 5 at 12z. The euro was only once a day to 7 days. The eta and ngm ran to 48. Nogaps to 6. And that was it. And when we would have our daily model analysis meetings at the weather station day 5 stuff was considered the same way most think of day 15 now. We barely paid it any attention beyond general pattern trends. So the euro probably seemed less jumpy when it ran once a day and only to 7 but most didn’t even pay attention past 4/5 days.

Gefs makes no sense with its mjo forecast. The geps goes crazy into phase 5/6. Cfs and eps are meaderong in the COD. The gefs goes strong into phase 2/3 which are cold phases in the east February. So the guidance with the worst mjo looks best. The one with a good mjo looks like dog crap. Go figure.

The eps and geps both have a very workable pattern at the end. Neutral AO. EPO ridge. Gefs is a train wreck. Reloads the same +AO. Pac ridge north of Hawaii pattern. Normally I would say with the CFS, EPS, GEPS all showing a similar progression toss the GEFS. And science would say that’s the way to go. But would anyone be surprised if in this one case the gefs schools all the other guidance?

That’s a definite degradation

Furthermore “the euro is rock steady” isn’t a thing anymore. I don’t know if it’s because it runs 4 times a day now vs once back in the day. Or if it’s higher resolution made it more accurate but also more prone to tangents. But it definitely jumps around with specifics run to run the last several years. But usually it’s goalposts are closer to the reality and it tends to catch on first. But it’s not 100% and you can’t just rip and read it’s long range output as a gospel forecast.

Ignore the low off Norfolk and look at the whole picture. Everything else is pretty much the same. That low is tenuous based on exactly how the stj wave ejects. If it leaves too much behind and doesn’t phase it ends up suppressed. If the wave ejects healthy enough it phases and we end to with stronger storm. It’s a minor detail that leads to one major difference but on a pattern level the euro isn’t flopping around in the larger sense.

They wash out the MS and SS vorts there and so it’s all northern stream. The gem tries to kick up a NS dominant system the euro simply suppressed the SS wave.

It’s the surface temps. 38-40 might not be a torch but it’s not gonna work for snow. Verbatim that’s the look of rain mixing with slush bombs during heavy precip. Not saying it’s correct but those surface temps don’t support snow.