psuhoffman

True but so far the trend across all guidance Nams/icon/rgem has been a faster further south coastal capture at 12z. That’s just good.

We’ve been good. Just this once. Come on. Then I won’t ask the snow gods for a god damn thing for at least 2 years. I swear.

Omfg rgem!!!!!

I don’t think the confluence is the problem. That has to be moving out as the storm arrives or it can’t amplify on the coast and we get a weaker sinking wave and no coastal at all. The problem is the angle of that last vort of the pinwheel to our north comes down in a bad spot and as the trough to our west feels the influence it stretches out positively tilted. That wasn’t on guidance 5 days ago when we were getting 30” bomb solutions here. Confluence has reversed and backed off the last few runs but is still slightly MORE then those epic runs. What changed us the trough being positive on approach which then makes the transfer and capture process take a little longer. Longer pushes that process further up the coast since the low will be gaining latitude UNTIL its captured then it stalls and pinwheels. But we need that sooner v later. We simply need a quicker phase unfortunately if we’re being honest the model bias is typically the wrong way with this and if anything the phase tends to happen slower. Not always though. And the trough is trending better (less positive) the last few runs of the euro and the NAM made a significant jump south at 12z. So DC is still in the ccb game. But the interaction between the wave in the Midwest and that last NS SW to rotate around the Atlantic vortex is what hurt us imo.

You ninjad me again

Every storm is unique. Analogs give you goalposts but yesterday for instance the top 4 analogs included 2 storms that dropped less then 3” on the DC metro and 2 storms that dropped over 20” so you gonna forecast 2-25”?

@high risk and @ers-wxman1 can chime in with how much it does/doesn’t mean but the EPS does not support the dryslot on the op. Increased qpf significantly again especially over N VA. Very slight cut back from WAA but significantly increased the CCB from 18z and we thought that was a great run. Totals dropped SLIGHTLY along the southern zones due to the loss of some with the WAA and deform won’t help south of EZF but increased everywhere else.

EPS look really good for you. N VA Jack.

Good luck extrapolating where a deform of a coastal that hasn’t formed yet sets up in 72 hours from current observations. Let me know how that works for you.

Except the track looks pretty similar the last 2 runs. 0z was deeper and has a more broad h7 circulation vs a tighter closed h7 low 18z. Maybe that made a difference but the track didn’t seem north to me.

Yea but the ggem op was very wet so they simply supported that.

So it’s still a 6-12” snowstorm across our area so it’s not like it’s a full fail. But yes that’s underperforming that look right there. Even more so if you look at the whole progression, primary jumps from the KY OH border to eastern NC then tucks up east of OC. Perfection. But it’s possible the op simply overdid the dryslot on that run. Maybe it was a hiccup. Precip isn’t the most accurate at this range. If we actually get that surface and h5 progression I’ll bet it’s a better result.

Not necessarily. A better qpf mean could indicate the op dryslot was a bit overdone.

Dude has been trolling non stop for days. How can he take any post seriously when he is a whole clown.

To be fair the 0z euro looked great in every way except the QPF. If you just looked at the h5 and mslp you would think N VA northeast got 12”+ easy. Instead we sat under a dryslot forever.

Yea that is killing places DC south. Even with some marginal gains from part 2 it’s a net loss. Unfortunately the primary is shearing out and weakening so the WAA is dying as it gets to us. Suppression ugh lol

Yea exactly, thanks for saying it in way less words. Lol

After more examination the 0z was an improvement at every level. More amplified and better h5 pass. H7 looked slightly better. Better track. That dry slot was just a killer but that could be wrong. It certainly wasn’t a NAM type fail with the CCB.

We got the full tuck. Better track. Further SW. but it didn’t really work out to a better result. The WAA really got suppressed. That hurt DC south. Most places lost 1-3” there. Then we got stuck in the dry slot too long. And despite a better deform band it didn’t extend as far south into VA despite a further southwest stall of the surface low. That part shocked me. I looked at the slp first and expected a better result then what I saw when I looked at the qpf.

One last point with ccb trends. This is the Cmc ensemble. Totals in central VA went down ENE because the WAA trended weaker. But the CCB trended a lot better. This is just the ccb part from 12z to 0z overall

So with only the euro left...the NAM is late with the CCB and a miss but has the best WAA lol. But among the other guidance DC gets clipped good by the ccb on the gfs (yea too much rain due to gfs awful thermals) rgem, ggem and icon. And the UK is south and a VA to DC special. VAs results were hurt most tonight by a trend to suppress the WAA wave more. Unfortunately once you get SW of DC a higher % of their snow was always going to be the WAA. So that drying up will hurt the further south more and north less. The euro is big Imo. So long as it doesn’t agree with the NAM I don’t think we’ve seen a huge shift in the CCB. We have seen the WAA weaken and that’s a problem for the southern 1/2 of the region that need that to be the majority of their snow.

Luckily the areas most likely to fail with WAA are most likely to win with the ccb so it mitigates that somewhat.

That’s hilarious and so true!

It sounds counter intuitive but it’s a complicated setup. The suppressive flow is relaxing. As it does eventually the coastal storm will amplify, phase and get captured. Once that it will stall and tuck and where that happens to the NW is where the heavy snow will develop. Illustrated below by the ggem. the capture/tuck was perfect there for DC northeast. The heavy snow is banding in the deformation axis where there is the convergence of winds and sheer at different levels. Look at how the winds ahead of the h5 h85 and surface levels all converge on that zone. Additionally you have moisture transport into that zone from the east. So you add moisture, instability and lift from convergence and that death band is what you get! But one issue on some guidance is the h5 opens up as it presses up against the shear from that suppression and because of that the transfer process is delayed and so the low doesn’t phase and capture until further northeast up the coast? I give you the NAM same scenario but the low is further northeast at the same time AND it never really got its act together and synced at at all levels like the rgem/ggem did. The result is the ensuing snow bands set up north. But yes suppression had a part in that. It’s delicate though. The suppression is easing. If it eased too soon the primary could hang on too long. If it suppressed initially we lose some of the WAA wave then the coastal front could be further southeast and the secondary will develop further ots. It’s a tricky balance. Miller Bs are a pain in the a$$ compared to muller As to pin down. If this was a juiced up gulf low we probably would have a better idea how it’s going to go by now. But guidance has a notoriously difficult time with transfers and phases. I’ll never forget how EVERY model was giving be a 6-10” snow from the CCB in early March 2018 only about 12 hours out and then the whole thing shifted northeast and I didn’t get a flake from the coastal. On the other hand a similar storm in Feb 1996 was supposed to hit NJ and crushed DC with no warning. I never count on a ccb from a miller b secondary until it’s snowing from it.