psuhoffman

Where you been friend?

Euro was kind of the model the most "in the middle" so it makes sense it would change the least as we get convergence among the others...

With the euro to go (and obviously that could change things quite a bit) this run has been the first time I saw legit improvement across the guidance and not just grasping at noise level changes. Until now I felt each run was a very slow bleed in the wrong direction but 12z was an actual improvement across everything so far imo.

It has trended warmer...and some of the warmer guidance like the GGEM has trended colder...they are meeting in the middle...for us right on the line where exactly that middle is means a lot

@caviman2201 thanks for the UK map...any way you could post the one through the end of the storm...I think north of 70 gets more snow after 18z based on the thermal and precip maps. Thanks

Thanks...any way you would show through the rest of the storm for those of us further north...I think we get a little more snow after 18z north of 70 But that looks like a slight improvement from 6z, in line with most of the other 12z guidance

Interesting but the US high res models aren't showing colder/snowier solutions than the GGEM/UK/Euro so...not sure what the point is from a functional POV

After seeing the entire 12z suite I think the issue with the NAM is simply it's weak sauce south of the PA line with the WAA precip. Had the nam looked like EVERYTHING ELSE wrt that it would have been colder.

I don't have access to the Kuchera maps...the UK 10-1 maps are always inflated because they include ice as snow, which in setups like this...makes them look better than they are.

There isn't really a defined, closed circulation low there, it's a trough axis with elongated low pressure along it...slight changes of where exactly the "lowest" pressure point is along the trough axis at any given moment can change where that map decides to place the "L" which makes the change look more significant that it was.

The UK ptype maps had a glitch...shows snow in places that are clearly above freezing at 850 at 15z Sunday. It still has a good thump legit for the area, 6-8" from what I can tell DC north to PA line... but the maps have to be thrown out because its not calculating precip type correctly

I think what it will come down to is the intensity of the WAA precip Sunday morning to midday. The NAM issue IMO is it's a bit lackluster in that regard over VA and MD south of 70. There is a disconnect between the h7 and h85 FGEN and the lift is displaced from the DGZ and the precip just isn't cranking like we need. The mid level temps jump way north during this period where the precip is less than thumpy and it never recovers...you see once the warm layer hits where the heavier precip is ongoing along the PA line it stalls for a while...we need that to happen further south...which it would IMO if there was heavy precip going on to fight the warming. What I would like to see is what the thermals will look like if the NAM comes around to look like what all other guidance does in terms of the precip profile during the 9z-15z time period.

It's the sleet, if you add up the just snow and the just sleet panels...it looks close to that depth map

Yea as I said to DD, the good news from this run was while it didn't actually help us as is...the trends took it close to being a big deal...it's one of those things where it needs to reach a critical tipping point and this got most of the way there...but not enough to significantly change the results...one more shift exactly like this and it would! We were much much closer to a significant snow event here than on the previous run, it just didn't quite get there. SO we still end up sleeting for the same amount of time...but if you look at the thermal profile...its way closer to snow during the day SUnday than it was on the last run

If I am putting my glass half full glasses on, both the 12k and 3k NAM are now very close to a HUGE event for our area...it would only take like a 30 mile adjustment southeast of the snow/sleet line during the 6 hour critical period Sunday midday for our area to go from 6-7" to 15" of snow! It's really close...the warm layer is not very big in our area...so as is it's not a great run, it's within a reasonable adjustment from being much much better.

FV3 was based on the GFS physics I think, and often is pretty close to the GFS so there is that.

I really thought we had a cushion (the thermal boundary is starting out so far south this time compared to those two events you just cited) that DC had at the minimum like 6" of snow before a flip. But the NAM is bothering me...it just blasts the h75 warm later up faster than the precip is advancing once the trough starts to approach and the SW flow hits us...such that it's implying despite how far south the boundary is ahead of this...DC might barely have any snow before the sleet...the "thump" might just be mostly sleet. You buy that?

It's worse for VA up to about DC...it's better for us...but what's frustrating is despite some pretty decent synoptic improvements...I liked the track of the low and orientation of the thermal boundary better...the coastal development...there was a lot I liked about the run...it got significantly worse in the one freaking thing that actually matters the most...it simply warmed the mid layers a little which blasted the changeover to sleet up a few hours faster during the most critical time period. If the thermals from the 6z had held with the other improvements from 12z it would have been a significantly better run.

12k is weird and annoying, in that it trended better in almost every way I wanted...better trough amplification/orientation, better coastal, colder initially...but it trended worse in the one way that matters most, it blasted the mid level warm later up about 3 hours faster...depsite all the other improvements...it basically just said...yes its better synpptically in every way...but lets just make it warmer to F with you.

9z to 15z is really it. DC has to max qpf in that window. NAM last 2 runs had a dryslot limiting qpf during that critical period.

It is but the bigger issue last couple runs was it had a funky dryslot at the most critical time periods when we needed the thump

I’ve decided to just pretend the GEFS knows WTF it’s doing

Rgem was a little of both. It did trend a little SE with the whole thermal boundary but then it also death banded us.

Guidance is trending towards a colder start and a better band out ahead early Sunday. That’s limits the “bust” potential. But we’re also losing the big upside as pretty much everything except the gfs (and we know it can’t see mid level warmth) changes us over now so the 15”+ type solutions are totally gone now. Things have narrowed in on a 6-12” snow to sleet event for most of the area.

Considering NWS has me in 18-24” “could get a foot” seems reasonable. I’d go 8-12 for my area no idea what NWS is smoking.