Snow Potential Dec 26-27

[Krs4Lfe]

15 minutes ago, RU848789 said:

The NWS offices in Philly and NYC kind of punted, lol, keeping all of the watches up and not reducing snowfall forecasts much in the updated map vs. yesterday afternoon's map, other than trimming back a bit near 276/195 and in EPA and on LI, although their discussion talks about reduced snowfall due to more sleet in the W/SW counties that have watches and due to more rain possible for the SNJ counties that have watches. Hard to blame them as there's still almost 36 hours before the event starts and this way they don't have to change twice.

 

Yeah looks like a big sleeter south of NYC. A few more nudges north (not even including the storm will probably be under modeled as to the northern extent of the sleet because this is a SWFE yet) and sleet will probably be quite prevalent in NYC. I’d cut the totals from CNJ on south in half. 

[winterwarlock]

Mt holly is going to bust badly if they dont start following the modelling

[Roger Smith]

06z GFS not going for the north trend and looks reasonably similar to previous GFS runs. 

[MJO812]

34 minutes ago, Roger Smith said:

06z GFS not going for the north trend and looks reasonably similar to previous GFS runs. 

Gfs looks great.  HRRR also.

[MJO812]

Icon

[SnoSki14]

6 minutes ago, MJO812 said:

Gfs looks great.  HRRR also.

RGEM not being amped is a big sign too. I really think it's just going to be a wall of snow that quickly drops several inches and then when rates lessen it turns to sleet/zr

[snowman19]

The 6z hi res RGEM and the 6z 3K and 12K NAM runs are showing a strong mid-level warm nose all the way up into Rockland, Orange, Sussex, Passaic and Bergen, Westchester. The Ptype goes to a sleet fest. This should be taken seriously due to the fact this is a WAA event

 

[MJO812]

Euro looks better than the 0z run

[snowman19]

1 hour ago, Krs4Lfe said:

Yeah looks like a big sleeter south of NYC. A few more nudges north (not even including the storm will probably be under modeled as to the northern extent of the sleet because this is a SWFE yet) and sleet will probably be quite prevalent in NYC. I’d cut the totals from CNJ on south in half. 

Warm noses are always underestimated at this range. The fact that the mesos (hi res RGEM/NAM) are showing a strong mid-level warm nose all the way north of NYC is a red flag. They turn it into a sleet fest. Ignore at your own risk. Globals (GFS, ICON, CMC, UKMET, EURO) are not going to pick on it as good as the mesos. Today is the day to take them seriously. Larry Cosgrove said many years ago ‘do not ignore the meso models showing mid-level warm noses in a WAA event they are usually right’

[Snowlover11]

Besides the shitshow NAM, looks like so far the northern bumps have eased for now. Hopefully that continues into 12z. 

[snowman19]

6 minutes ago, Snowlover11 said:

Besides the shitshow NAM, looks like so far the northern bumps have eased for now. Hopefully that continues into 12z. 

The only thing the NAM is good for is accurately showing warm noses. It surprisingly excels in WAA events. Other than that, it’s completely useless 

[wthrmn654]

2 hours ago, RU848789 said:

The NWS offices in Philly and NYC kind of punted, lol, keeping all of the watches up and not reducing snowfall forecasts much in the updated map vs. yesterday afternoon's map, other than trimming back a bit near 276/195 and in EPA and on LI, although their discussion talks about reduced snowfall due to more sleet in the W/SW counties that have watches and due to more rain possible for the SNJ counties that have watches. Hard to blame them as there's still almost 36 hours before the event starts and this way they don't have to change twice.

 

Long Island totals are over 6 inches now yet still no watch lol

[donsutherland1]

From the WPC:

[Roger Smith]

Widespread 60+ dewpoints in developing storm's warm sector, as long as it turns southeast far enough west to avoid flooding low to mid levels in NYC region with 40-45 deg air, I could see this becoming a heavy snow situation for wherever surface temps are closest to 28 F. And that currently looks like ne PA to n/c NJ to NYC and LI. 

It is a WAA event except that it is going to be rotated around by 45 deg compared to many of them, which I believe will tighten up gradients and lead to a wall of snow outcome. There will be a lot of thunder and lightning across PA into s NJ and n DE during this storm's development phase Friday afternoon-evening. 

Key point to evolution is that a weak wave tracks e.s.e. across region tonight, reinforcing surface cold and that colder air will flood into the east coast region before the low really reaches full potential, so that will create a fairly resistant cold layer below about 850 mbs. Taint factor may be overestimated for NYC metro by some, but time will tell. 

[North and West]

Widespread 60+ dewpoints in developing storm's warm sector, as long as it turns southeast far enough west to avoid flooding low to mid levels in NYC region with 40-45 deg air, I could see this becoming a heavy snow situation for wherever surface temps are closest to 28 F. And that currently looks like ne PA to n/c NJ to NYC and LI. 
It is a WAA event except that it is going to be rotated around by 45 deg compared to many of them, which I believe will tighten up gradients and lead to a wall of snow outcome. There will be a lot of thunder and lightning across PA into s NJ and n DE during this storm's development phase Friday afternoon-evening. 
Key point to evolution is that a weak wave tracks e.s.e. across region tonight, reinforcing surface cold and that colder air will flood into the east coast region before the low really reaches full potential, so that will create a fairly resistant cold layer below about 850 mbs. Taint factor may be overestimated for NYC metro by some, but time will tell. 

.

[TJW014]

16 minutes ago, Roger Smith said:

Widespread 60+ dewpoints in developing storm's warm sector, as long as it turns southeast far enough west to avoid flooding low to mid levels in NYC region with 40-45 deg air, I could see this becoming a heavy snow situation for wherever surface temps are closest to 28 F. And that currently looks like ne PA to n/c NJ to NYC and LI. 

It is a WAA event except that it is going to be rotated around by 45 deg compared to many of them, which I believe will tighten up gradients and lead to a wall of snow outcome. There will be a lot of thunder and lightning across PA into s NJ and n DE during this storm's development phase Friday afternoon-evening. 

Key point to evolution is that a weak wave tracks e.s.e. across region tonight, reinforcing surface cold and that colder air will flood into the east coast region before the low really reaches full potential, so that will create a fairly resistant cold layer below about 850 mbs. Taint factor may be overestimated for NYC metro by some, but time will tell. 

Somebody had too much brandy in their eggnog last night

[EastonSN+]

2 hours ago, RU848789 said:

The NWS offices in Philly and NYC kind of punted, lol, keeping all of the watches up and not reducing snowfall forecasts much in the updated map vs. yesterday afternoon's map, other than trimming back a bit near 276/195 and in EPA and on LI, although their discussion talks about reduced snowfall due to more sleet in the W/SW counties that have watches and due to more rain possible for the SNJ counties that have watches. Hard to blame them as there's still almost 36 hours before the event starts and this way they don't have to change twice.

 

[SnoSki14]

Well the good news if we get screwed is that it all gets washed away in a couple days anyway. 

At least we're getting snow opportunities this year

[the_other_guy]

2 hours ago, winterwarlock said:

Mt holly is going to bust badly if they dont start following the modelling

They cant be like the razors edge of emotions in this forum dude. They are a govt agency that people depend on for stability of information.

At some point they have to convey to millions of people that a major winter storm will be threatening the region tomorrow that will make travel difficult and potentially life threatening and they dont need the noise of 1-2 inch differences between each model run to undermine that obligation.

[EasternLI]

2 minutes ago, SnoSki14 said:

At least we're getting snow opportunities this year

Quite far from being done with that too IMHO.

[SomeguyfromTakomaPark]

6Z euro is a great run for nyc metro

[Snowlover11]

1 minute ago, EasternLI said:

Quite far from being done with that too IMHO.

I would hope so it’s December  not April.

[NEG NAO]

[sussexcountyobs]

3 hours ago, winterwarlock said:

Mt holly is going to bust badly if they dont start following the modelling

Imagine the chaotic forecast the NWS would have if they just used Modelology, and not Meteorology. Changing their forecast every couple hrs, when a new model run comes out. It would be ridiculous, and no one would pay them any mind.

[EastonSN+]

Merry Christmas all

[BoulderWX]

13 minutes ago, NEG NAO said:

That’s a huge 6-10” area - quite bullish, im

surprised given his forecasting style. 
 

merry Christmas, all! 

[forkyfork]

the nam is usually the best at sniffing out these warm noses. merry christmas!

[ag3]

7 minutes ago, forkyfork said:

the nam is usually the best at sniffing out these warm noses. merry christmas!

But it also has whacky runs before it adjusts. Today’s runs will be telling.

[North and West]

They cant be like the razors edge of emotions in this forum dude. They are a govt agency that people depend on for stability of information.
At some point they have to convey to millions of people that a major winter storm will be threatening the region tomorrow that will make travel difficult and potentially life threatening and they dont need the noise of 1-2 inch differences between each model run to undermine that obligation.

They’re not concerned with the unhinged emotions of adults acting like adolescents. They’re looking at it from the scope of life and property protection for normal people, not unhinged lunatics.


.

[RU848789]

1 hour ago, EastonSN+ said:

Significant trimming back of snowfall for areas south of 78 in PA and W NJ and near/south of 276/195 is what I was expecting to see at 4 am - not sure why it took them a couple more hours to do so.  I do like the single map showing NWS-Philly and NWS-NYC together (although it does miss the northern edge of the NYC office counties), better, though, so here it is.