SnowGoose69

My memory is the RAP tends to have a west bias at this range

The HREF is again going too high...mean is like 2-4 near the metro but its been consistently bad this year after it was very good last winter

Yeah...I posted in the NYC forum how on 2/8/13 we were snowing heavy here with a surface low over Cape Cod at 06z. you can get a mass expansion of the snow shield in the window when there is a close off and full phase

The GFS was not exactly good either, it was sending this to Bermuda...it was more correct for the wrong reason

The good news is its due for an upgrade soon...the bad news as a poster said here last night is the NAM is set to be discontinued perhaps....its fallen behind schedule since the plan was for the HRRR to run to 84 I believe, but as we've seen the HRRR often has a major BL cool bias beyond 18-24 and sometimes even a midlevel one too

Yeah he's not wrong with his ideas. I saw that on twitter...I do not buy the huge snow shield the HRRR/3K have back into our area tomorrow at all. I understand what they're keying in on to have that but to me the system is simply closed off a tad too far east for that to happen...its not crazy though that maybe the N Fork of cntrl to E Suffolk and maybe places like HVN could get in on a decent period of snow in the afternoon tomorrow. The DPs are cold enough this time that no question on a N flow places could get to 32-33 and accumulate

I think where you are the HRRR/3k ideas tomorrow are not that crazy but the snows it shows back as far as SW CT to me are probably bogus as the whole evolution of the storm IMO is too sloppy to produce that degree of snow coverage

I'd take the CMC idea from 48-54...it would probably be mostly snow in the city despite what it shows if that unfolded. the 700mb temps of -11 to -12C are colder than the magic number often used to determine if in a scenario you're trying to cool the airmass in a CCB scenario you want to see -10C or colder at 700 to be confident you're going to get down to 33-34 or less at the surface...this is a rule some older mets have used

This is such a wildly convoluted set up I probably wouldn’t trust anything at the moment. Chances are you can throw out the NAM GFS and probably just mix the euro and the Canadian but as we saw on the 6z RGEM it barely even has any snow in Boston. the problem is the RGM is a fairly lousy model past 48 too with a set up such as this. It can do well with simple systems beyond 48 but when it comes to convoluted phases and coastal systems with phasing and captures it can be pretty terrible past 48.

I'd be fairly scared if I was them about going big at all with snow right now near the coast but I'd probably at least cover with 1-2 inches possibly for now

The UKIE made like 3 attempts to go full GFS in the 18 hours prior to it fully consolidating. You can see not just the GFS is struggling with the evolution of this

It was sort of 00Z NAM/GFSish at 12Z...it tried to do it again but did it less and consolidated better which is what made the difference

We've seen double barreled setups before with these E coast storms but not in setups such as this

As we saw on 2/8/13 you can get pretty big snows with the surface low way east if you have completed the entire capture and phase...NYC was snowing heavily at 06Z that night with the SFC low way east. I would not exactly expect that we are going to get that scenario though http://www.meteo.psu.edu/ewall/NARR/2013/us0209.php

The problem we have is even the Euro is way too warm at 925 for most of the event as was posted in the SNE forum (you can see maps there on recent pages) you'd basically not snow here til roughly 78 hours or so. No question the more SRN stream this trends the more likely we see big snows here. You might see models move hard one way or the other at 12 or 00Z today now that everything is onshore

This setup is probably too convoluted for the NAM to get it right at this range.

The Euro could definitely be wrong trying to be too SRN stream involved for sure...its done that before when the CMC/GFS are trying to say the NRN stream will be more of an issue

Its just way more southern stream involved but the general tendency is GFS better with NRN stream/EC better with southern...not sure which is right but no question Euro is sort of on its own right now

Actually most storms its occurred before that lol. There has been ticks that have gone bad inside Day 5 but in general this winter models have sort of locked onto a general idea at Day 6 or 7 then held it from there. We've lost like 5 storms to cutters at 130-150 that never came back but ultimately maybe shifted 75-100 miles which impacted places like Buffalo or Detroit but one of us cared

If its raining in NYC with that thickness and low position then I am officially declaring myself God

We dry slotted more or less...we were cold enough

Yeah I have no concerns about the air mass with this unless it basically just tracks so far east it misses but if this thing goes up over SNE its likely going to snow everywhere

This one won't really have an issue at all if it tracks where the Euro/ICON for example have it going...we have a decent cold source to pull down. I think this system is gonna bomb, its just a question if it just goes way too far west but I do not expect lack of dynamics to be a likely issue with this one

snowman has semi joked about this all winter but reality is this rule can sometimes still work...we've yet to see a case yet where the GFS was trying to go to the fish and the other guidance was all a decent hit overall at Day 4-5...this really is the first case where as a whole the GFS is where you want it at this range or at least most runs has been

This is a rare case where NYC can do better than SNE if the storm takes the right track...it would be fitting in this winter to see something odd like that happen