SnowGoose69

1 hour ago, jm1220 said:

It’ll be a race between the heavier snow rates and the warm nose aloft. If the heavier rates work out, many of us even the city and coast can see 2-3”. If it’s shredded up, the warm air will have an easier time advancing and sleet/rain will mix in earlier. In the shredded up case I doubt many near the coast/city get over an inch. We need strong lift and rates to hold back the warm mid level push. Maybe it can be held off until the precip is almost done. 

All comes down to can it begin snowing by like 08-09z.  If it can get in that early I think 2-3 is very possible even in NYC but if its closer to 10-11z probably more like 1 inch.  Could be a 2 hour period of pellets and still not sure what type of changeover really happens to rain outside of LI or south Queens and Brooklyn and Staten Island

The 18Z NAM now is in range with snow by Sat evening

34 minutes ago, GaWx said:

I don’t know how to describe this other than calling this pure insanity: is this real? Of course the NW trend could mean much lower, especially close to the coast, would verify. So, for now I’m not buying this much will actually fall:

Chances are the boundary won’t sit there that long or there won’t be as much activity riding along it as the Euro shows.  

I think there could be some surprises with this one, especially NE NJ/L HV area...usually in these events there is a region that is near the base of the high axis that really overperforms and sometimes does better than areas that end up staying mostly snow like say BOS/ORH in this case who have deeper cold air in place.  It typically is a combination of them sitting near the changeover line for a sustained period/not being as dry so virga is not as much of an issue and also frontogenesis.    Does not happen in all SWFEs but it seems to be often enough I always watch that area near the wedge axis at the base or back side of the high for it.

Just now, mitchnick said:

Really should use the bias corrected (bc) version. Still gets onto 8 but very weak.

Probably explains why to be honest the GEFS/EPS pattern just don't look a whole lot like phase 8 beyond D10, the wave is too weak, although the 12Z GFS Op run post 240 does look more phase 8ish on the pattern

This will end up as one storm, more like the 06Z AI shows.  You might see some type of real wimpy weak front running wave as the AI also shows over NC/VA the day before, but this long drawn out slow multi wave idea I don't think happens

31 minutes ago, NittanyWx said:

The only thing giving me pause about this storm (and it's a big pause) is the 850 low.  Screaming southerlies mean warm nose aloft is almost a guarantee to cause some mixing issues for pretty much all of the CWA.  I like the front end thump potential and you can hold off some of that warm nose with decent lift.

I think in the end it ends up similar to tomorrow AM's storm.  There are some aspects of the storm tomorrow I like better than I do this one, wave as a whole is weaker so mid-level WAA might not be as strong so it could surprise and stay snow longer.  This one has the look of one that might be best to the north right now.

I also think it ends up being one storm, not sure I believe the idea of a whole bunch of different waves riding the boundary based on how things have gone this winter.

Even the GFS shows signs of snow breaking out over NJ/PA earlier at night as the HRRR/NAM show.  Will have to watch this one closely for starting as early as 06-07z.

Closest setup I can find to this event, 2/21/05.  3-5 fell most places.  High was in a slightly better spot, albeit still not great.  The SFC low re-developed though and we got a NE flow after being south.  This time I think we'd get more sleet.  Shows you how a pretty close setup acts differently with small changes.

https://www.meteo.psu.edu/ewall/NARR/2005/us0221.php

6 minutes ago, winterwx21 said:

HRRR hasn't been great this winter. Let's hope this is an event that it's right about, but obviously we should be skeptical. This is long range for the HRRR too. 

Yeah I'd definitely not use its thermals but the idea its generating so much overrunning precip relative to the Euro is good

The 18Z HRRR sure doubling down on its idea, no notable move towards the Euro.  We'll see if the NAM begins to move towards it next few cycles

2 minutes ago, LibertyBell said:

pattern reload after that?

 

The Op runs definitely have more SE ridging than the ensemble average which tells me there probably are alot of ensemble members D12-16 that are not nearly as troffy or suppressed in the east as the GEFS/EPS average is

48 minutes ago, Allsnow said:

The euro continues to be very warm with very little frozen to start with this system. 

Its not tremendously different on thermals, it simply has no QPF til like 13Z

1 minute ago, weatherwiz said:

It's pretty impressive seeing how cold MOS/NBM is for tomorrow night...even down in place like EWR/JFK. 

SE flow is just weak, it does not really crank til the system is already producing precip, and near shore water temps are now fairly cold.  I am not sure even down here if anyone except Long Island and the south shore of NYC ever goes above 32.

I agree with Walt on that 12th-14th storm, there is definitely a risk of suppression though I think suppression is the wrong word.  As I said yesterday, its more "failed phasing" or disjointed setup than it really would be suppresison

Wide range of risk on this one, anything from about the same as the 2/6 event to significantly snowier is possible.  

2 minutes ago, EastonSN+ said:

FWIW the CMC is colder and mostly sleet now as opposed to rain. Almost never gets to rain fully, mostly sleet to dry slot. 

Its very possible places from N Queens on W-NW never go to rain on this event, while there is ESE flow, its light, the event is very fast moving and short duration and there may be too much wet bulbing initially to push temps over 32 til the precip is almost over.  LGA is roughly 32/21 at the start, if they fall to 28 I really doubt an 8-10kts wind from 090-110 blowing across a large area of sleet/snow on the ground is going to get them over freezing before the event exits.   I still think there is mostly sleet though after maybe 2 hours of snow at the start.

23 minutes ago, Spanks45 said:

Hopeing that 6z Euro was just a blip....everything else seems to be a nice thump down here, even the Long range hrrr and rap were plenty cold to start...

06/18z Euro runs the last few years have tended to do some strange stuff.  Should not be happening with today's model ingests but I've seen it more than enough times to know its a tendency at this point

The Euro seems out to lunch on this one, I am still wary of totally discounting it, maybe the 06z run was a blip but its evolution overall is just different than any other model right now.

6 minutes ago, weatherwiz said:

These setups tend to be quicker versus slower for precip. arrival so I am almost inclined to side with the NAM timing wise. 

The NAM is almost always the slowest model when it comes to start times, the fact its consistently been the earliest for the last 2 days tells me it might be right

Just now, MJO812 said:

Suppression isn't going to be an issue this time around . We don't have intense blocking modeled. 

I'm not worried too much about suppression as I am maybe storms not being able to amp up quite as much if the SER is flatter than that Op run shows 

The GFS still could be overdoing the presence of the SER so I am not sold post 2/13-2/14 that storm tracks are going to be that far north.

The AI which has probably performed best on start time in many of these precip events has 07-08z for NYC.  Probably means the UKMET/GFS/Euro might be too slow right now and NAM slightly too fast.  It also has a slight wedging signature showing up.  I think NE NJ/N parts of NYC have to be wary of this event staying frozen for most of it.  We'll see what the NAM shows as it gets closer.  As of today it shows most places turning SE on winds

2 minutes ago, wdrag said:

Yes,  I keep the door open for changes within the broad pix. And yes, I look at snow/ice probably more from a hazard view than actual perfect numbers - I ball park numbers. Too much stuff can wrong on numbers (just like the CP change this morning at 631).  

I'm guessing 1//2 to 3" heaviest case for NYC CP Wed night.  

Am offline til a short time on this eve, then back full bore tomorrow morning. 

Definitely need some sort of mesoscale help on this one to get more than a quick shot of snow, high positioning just not great though some higher res models show it could try to wedge itself in for a bit.  Its why I am nervous about LGA/EWR on north holding onto ZR or PL longer before going to all rain but the event that follows this one looks more promising though I still think its the 10th and beyond when any all snow event is likely.