weatherwiz

99.999999% of the time I am extremely conservative with snowfall forecasts but sometimes you gotta chuck high and far

Very confident in these ranges but obviously may have to do some shifting once we get a precisely clear consensus. I do think we'll see a max jackpot strip of 24-30'' but not sure if that includes Connecticut. I am fairly confident though we see heavy banding get much of Connecticut. Thinking snowfall rates 3-5'' under the band with ratios upwards of 18:1 to 20:1 (though I'll admit I'm not sure how to factor wind into lowering these).. Two big things of note: 1) QPF is going to be high 2) Lift will be through the roof 3) Way better than 10:1 ratios.

Eye candy time

Agreed. We still have a bit before those complicated process are fully resolved. The spread has lowered some but is still high enough to result in a wide swing of possibilities on a local level.

Completely agreed with the bolded. You're though talking about the evolution and track. I am just referring to the initial low pressure development. If the initial low development say is further east...with the changes in the trough that will result in an even more east swing. If the initial low development is farther east...with the changes in the trough you still get the east swing but that east swing isn't nearly as far east. you still have a more west track.

IMO it would impact how the low evolves/tracks...not necessarily initial development.

I don't know though if that's impacting where the sfc low first pops off the southeast coast. there is energy well ahead of that southern s/w in which the NAM is closer to the coast and the GFS is farther east Unless I'm totally wrong on this, low pressure development initially usually occurs very close to or right along the baroclinic zone (which is virtually just off the SE Coast...on all models). Even when looking at mid-upper levels that would favor initial development just off the coast...not as far east as GFS has

Like the GFS pops the sfc low much farther east than the NAM/Euro which (even though there are the slight differences with the shortwaves) could also explain a more east push and then a subsequent later capture.

Given where the baroclinic zone is on the GFS (unless the other factors are just playing a bigger role overall) I find it tough to believe the eastward track.

does the Euro/NAM combo rule still apply

Obviously going to have to factor wind into this somehow (which I will admit I don't have much knowledge on) but 12z NAM bufkit is spitting out some pretty impressive ratios. I wonder have to think under the CCB ratios probably approach 18:1 with snowfall rates 3-4'' per hour...maybe upwards of 5''.

same! just have to fill in some blanks after the full 12z suite (which for me is NAM, GFS, Euro...I don't care about any of these other models which I know is bad on my part). I already have an idea for snow map but given the magnitude I don't want to put it to paper yet until all 12z but I am certainly thinking 18-24'' for at least CT River East. Can't really do much with banding/subsidence until probably Friday.

Certainly should have enough confidence to do an initial snowfall map after the euro today! Already prepping the blog. This is nothing more exciting

Precisely. We all know models have a tendency to overdo QPF but like you said these are exceptional circumstances. I mean when you have 80+ knots of warm/moist inflow into such a cold airmass...it doesn't take rocket appliances to know what that will do or means.

QPF will absolutely NOT be underdone with this. I mean this inflow is ridiculous

For those asking

Definitely using more for eye candy but also just trying to illustrate and hammer in a few (negative) things to keep in mind and watch for as we get closer and it's time to talk potential snowfall totals. But I totally agree with everything you said. Forecasting exactly any banding where set up and traverse is not going to be easy and that's going to be dictated by several different factors. I actually also believe the main band will end up farther west. I think I touched upon this in a post earlier this morning or afternoon but I can see a scenario where the main bands becomes established well northwest of where models are indicating now...and this is a result of the mid-level centers developing and initially being elongated. However, as the storm rapidly organizes and the centers tighten, you'll see the main band quickly collapse southeast closer to the centers. Then from here it's a matter of does the band sit and does it have the potential to pivot? I also think we will see a secondary band form...which tends to be the case in these stronger systems. This is something which may initially favor some subsidence between the two bands but getting into what you were saying, the strong easterly inflow may help fill this in a bit or maybe the two bands converge. But I can absolutely see the main band being much farther west than what's advertised now

I am mostly playing around. I know it's early to really dig into these details but I love looking for the weenie aspect. I just looked at the PYM bufkit and yeah...that is absolutely wild

In these sense of where this occurs but it's likely pretty right with this idea.

That is an absolute crushing in SE MA. With a giant screw job in the CTRV

Very odd from the 18z GEFS, however, I think you can kinda see why the mean was farther east. Just comparing 12z GFS/18z GFS (no comparison to other models) looks like there are some deviations in the evolution of the southern s/w between about 0z-12z Saturday. There are some differences with the north stream too. While perhaps an outlier this still tells us that despite getting closer, any subtle changes with any of these features is going to yield wide swing in potential outputs. The goal posts are still wide-ish

It's definitely stronger and a bit more west with the ridge axis compared to the 12z run and 18z NAM...here we go

Almost forgot 18z GFS is running. Anthony forgot to remind us...what a slacker

Just give me a 980's or 970's low as it's passing southeast. Getting anything deeper (especially too intense deepening) and bad things happen. Precip starts to get more banded so while some cash in you need to be lucky and occlusion can happen to rapidly so you choke off the moist inflow and the CCB just shuts off and everything goes to poop. Save the 950's for tropical

Beautiful. I have a shaky hand.