psuhoffman

Full tuck at 1am

Baby step

Slightly more ridging in front and a slightly more amplified h5 at 33 hours. Heights to the NE maybe a slight smidge less suppressive

@Bob Chill welcome back!!!!! Missed you

18z gefs really ramped up the deform Monday!

If it slides ENE from there you will.

Ok it’s been fun but it’s time for the euro to tuck this biatch right up against the Delmarva and end the suspense.

it moistened up some though...the 3K sometimes does whacky stuff outside 36 hours.

NAM took a significant move towards the other camp this run. Gets DC better with the deformation zone and is still snowing at 84.

I think we can add the JMA to the majority tuck camp. Its super hard to tell from 24 hour timestamps and super low resolution, and the key time period is kind of missed in between hour 72 and 96 hours...but it looks identical to the GFS/CMC at 72 and from the precip and making reasonable inferences I estimate the JMA adds about .35 qpf from the CCB after about .4 qpf from the WAA wave. That is pretty good btw for the JMA which is low resolution. Even if it was only .35 that would imply a 4-6" snowfall across the area (on top of the 3-6" from the WAA part) given typical high ratios in the deform axis. But that qpf is likely conservative. And that is the most analysis I have ever done or ever care to do again of the JMA. But that was for @Ji. Take care man!

Ensemble members will struggle to show HUGE totals because they are lower resolution and the snow maps are 10-1. It's very likely an 8" ensemble member is really a 12" snowstorm...maybe even more honestly. That said...the crazy huge totals of a few day's ago are probably off the table because the flow to the northeast has trended more suppressive which has caused the trough to remain more positively tilted then it was when we were seeing those 30" type solutions. It's not impossible to get back to that...but we have some work to do. I think setting the bar at a solid MECS is more realistic.

Be careful using the mean on the EPS because there are two still 2 distinct camps wrt where they capture the secondary. The good news is the improvement on the mean is because about 11 members jumped ship from the eastern escape camp to the tucked in camp. The majority camp went from a slight 55/45 lean towards OTS at 6z to a 60/40 lean towards a quicker capture and tuck. The OTS option is still there and there is a not insignificant camp that support the OP but it was a clear move towards the other guidance.

we have a conundrum... the GFS/UK/GGEM/RGEM/ICON/NAVGEM all agree on phasing and tucking the low off the VA capes which places our area under the deformation axis. The Euro/NAM jump the upper low further northeast and have the capture happen further north and OTS which misses us with most of the effects from the coastal. Obviously the preponderance of evidence suggests the south solution but we have the EE rule saying no. Tough one. The euro moved in the right direction 12z so I am going to favor the closer to the coast solution ATT.

@MillvilleWx good catch. I think the h7 and h5 issues are linked. The runs that do not open up the h5 and amplify it from the OH valley across VA to the coast jump the h7 in and phase "clean". The runs that stall the h5 then jump to off the coast do not because the storm is not "phasing" yet. The phase gets delayed (which for our area is a killer) as the H5 makes the jump. We want the h5 to stay closed off and start to phase as it crosses VA not jump to off the coast...and we probably get the h7 feature you pointed out to respond. They are symbiotic imo.

It has been a compromise but the GFS didn't even see the coastal at all for our area until recently. At this point yea they are converging and run to run the euro might cave to a detail on the GFS at this point...but lets not forget from 5 days the GFS was totally clueless as usual.

This was so close in so many ways to something much bigger... We don't even need it ALL to come together we just needed either some combination of slightly more backing off of the feature in New England or faster with the feature diggin in behind, and probably only slightly, and that H5 doesn't open up and instead amplifies across to our south which links up with the mid level moisture feed off the coastal and activates the deform axis over our area.

yes but the euro trended a little better this run. It was the first time it nudged the "other way" in 36 hours. The trend is USUALLY (not always) to relax features up there a little at the last minute. Not a ton but usually once you get inside 48 hours you see some relaxation of the flow to the northeast as the next wave approaches. This isn't any great insight just stating typical model bias over the years...of course every situation is unique. I was happy to see the euro start to back down with that crushing feature even if just a little. If you loop the H5 trend at 72 hours from the last 3 runs its a little closer to a better phase for us imo.

@stormtracker...illustration... look how the h5 jumps over us...we need it to stay closed and phase over VA not jump too off the coast like that. But it was VERY close...the track is perfect just need it a little more amplified and the trough less positive so it doesn't open up. But look at the trend the last 3 runs...one more adjustment like that and it will.

looking at h5 this run was actually closer to a tucked solution...but it just missed. The confluence backed off some and it almost but the H5 opened up at the last minute instead of phasing in with the coastal which cut off the moisture transport from the coastal into our area and failed to really activate the deformation zone. Instead the focus became the fgen region to the north of the developing coastal. But its a delicate thing...its not like there was no deform zone...it just wasnt the beast it could be if we get a better transfer/phase which we will if that feature in New ENgland can BACK OFF just a bit more. This is one of those runs where the clown map says it was worse but it was closer to something BIG. Unfortunately it did show the "fail" relatively (it still would be a decent snowfall) option for DC with the split where the best lift from the WAA stays south of DC and the lift associated with the FGEN ahead of the h5 and from the developing coastal stays north. That is often the "DC split" miller b thing. But get the h5 to not open up and phase in and suddenly that weak band is dumping on DC Monday.

come on capture and tuck....do it...you know you want too...just do it

I thought I controlled myself pretty well considering what they run did to me...I made like 3 posts after the euro then went to bed. lol. I still like where we stand, especially 95, I just don't like the introduction of that feature in New ENgland adding uncertainty. Uncertainty sometimes doesn't work out the way we want and damnit I want this snow curse broken NOW.

would you agree that if we do get a more tucked capture stall like the GGEM/UK we also likely get the typical NW deform band that guidance almost always misses with amplifying mid atlantic coastal systems. Seems to me, and please correct me if I am wrong, that guidance from range tends to focus the deform band along the best fgen associated with the moisture transport from the coastal where it intersects the CCB and the instability from the upper low. And there will be a band there...but what it often misses is the increased forcing along the NW fringe of the CCB where the moisture transport hits the "brick wall" of confluence to the north. That resistance typically seems to add lift and while its not to the degree as further south you also tend to get really high ratios there. IMO those 2 factors contribute to that deathband we often see that guidance totally misses on the northern fringes of the CCB.

Not as bad as on the RGEM/GGEM. My area kind of is in a screw zone of subsidence between bands but that is not something I am going to worry about at this range...and we all know that if the southern PA/northern MD area gets into the actual CCB good banding will set up here due to oragraphic influences. Mappy's area gets absolutely crushed with one of those bands but the UK has some weird dry pockets mixed in that screw over some areas (me) lol. Even if that were true it wont nail that from this range.

IF (huge mega if) we do get the further southwest capture/stall option guidance will underdo the snowfall in that deform bad. That is a 90% given. They also will miss the NW deathband...we all know that. But that only works out if we actually get the close to the coast capture stall option...if the storm swings out too wide due to a positive tilt precipitated by the flow too suppressive in front...the area will be robbed of the moisture transport we need off the coastal as the upper low swings through and it will just be instability disorganized areas of snow.

UK is a picture perfect capture/stall location for our area. Hopefully the euro follows.