12/15 - 12/16 Coastal/Winter Storm & Observations

[wishcast_hater]

From my local NWS office:

 

As for precipitation type, this is where confidence decreases.
We are confident that higher elevation areas will see mostly
snow from this system, with impressive snowfall totals in many
cases of 12-18" or more. However, snowfall accumulations are
much less certain for valley areas despite models having
generally converged on a low track from eastern NJ over Long
Island and then over RI. At this time, thinking that even valley
locations see snow to start. Snow quickly transitions to rain
along the I-84 corridor. Further north, the transition is
expected to take longer, with the Capital District potentially
seeing snow through 7-11z before the changeover begins. However,
there are several complicating factors, and a temperature
difference of just a degree or two could make the difference
between several hours of snow and several hours of rain.

Some of these complicating factors include: the fact that
radiational cooling may lead to temperatures below those
expected by model guidance to start the day Thursday.
Furthermore, with a cold high to the northeast, we will likely
see some cold air damming, which is often underestimated by
models. Also, strong forcing for ascent will likely lead to an
overlap of strong omega with the DGZ, and we may see dynamic
cooling where this heavier banding of precip sets up; also, if
snowfall rates are high enough we could see accumulating snow
where temperatures are 33-34F. On the flip side, a warmer
outcome is possible if a) clouds move in quicker than expected
tonight, b) if precip is lighter in the Hudson Valley due to
downsloping, and c) because the surface high is further
northeast than is ideal. After taking all of these factors into
account, the decision was made to increase snowfall totals
slightly in our latest forecast for valley areas, especially
from the Capital District northwards.

 

Overall, this will be a long duration event that will begin
Thursday evening and last into the beginning of the long term
period. When all is said and done, light to moderate snowfall
accumulations are expected for valley areas, with heavy to
possibly significant snowfall accumulations in the higher
elevations. We will continue to monitor latest trends and
update the forecast as new data becomes available

 

 

 

My buddy lives near Monticello, he is expecting 16" of snow....lucky bastard

[snywx]

12z NAM came in a bit snowier for the I-84 corridor. My initial thinking is a general 4-8” primarily W of the Hudson. The potential exist for 8+ in western Orange County >1000’

[IrishRob17]

Just now, snywx said:

12z NAM came in a bit snowier for the I-84 corridor. My initial thinking is a general 4-8” primarily W of the Hudson. The potential exist for 8+ in western Orange County >1000’

Yeah, a touch colder so I'm getting a little more intrigued now, lets hope this starts a trend.

[snywx]

44 minutes ago, wishcast_hater said:

From my local NWS office:

 

As for precipitation type, this is where confidence decreases.
We are confident that higher elevation areas will see mostly
snow from this system, with impressive snowfall totals in many
cases of 12-18" or more. However, snowfall accumulations are
much less certain for valley areas despite models having
generally converged on a low track from eastern NJ over Long
Island and then over RI. At this time, thinking that even valley
locations see snow to start. Snow quickly transitions to rain
along the I-84 corridor. Further north, the transition is
expected to take longer, with the Capital District potentially
seeing snow through 7-11z before the changeover begins. However,
there are several complicating factors, and a temperature
difference of just a degree or two could make the difference
between several hours of snow and several hours of rain.

Some of these complicating factors include: the fact that
radiational cooling may lead to temperatures below those
expected by model guidance to start the day Thursday.
Furthermore, with a cold high to the northeast, we will likely
see some cold air damming, which is often underestimated by
models. Also, strong forcing for ascent will likely lead to an
overlap of strong omega with the DGZ, and we may see dynamic
cooling where this heavier banding of precip sets up; also, if
snowfall rates are high enough we could see accumulating snow
where temperatures are 33-34F. On the flip side, a warmer
outcome is possible if a) clouds move in quicker than expected
tonight, b) if precip is lighter in the Hudson Valley due to
downsloping, and c) because the surface high is further
northeast than is ideal. After taking all of these factors into
account, the decision was made to increase snowfall totals
slightly in our latest forecast for valley areas, especially
from the Capital District northwards.

 

Overall, this will be a long duration event that will begin
Thursday evening and last into the beginning of the long term
period. When all is said and done, light to moderate snowfall
accumulations are expected for valley areas, with heavy to
possibly significant snowfall accumulations in the higher
elevations. We will continue to monitor latest trends and
update the forecast as new data becomes available

 

 

 

My buddy lives near Monticello, he is expecting 16" of snow....lucky bastard

Sullivan county should cash in with this event. 75% of that county is over 1200’. @crossbowftw3should do well too

[snywx]

1 minute ago, IrishRob17 said:

Yeah, a touch colder so I'm getting a little more intrigued now, lets hope this starts a trend.

It’s tough to pull the trigger on a big event lol. We are soo close to the big snows but that R/S is awfully close. Most guidance has 6+ for us too

[crossbowftw3]

2 minutes ago, snywx said:

Sullivan county should cash in with this event. 75% of that county is over 1200’. @crossbowftw3should do well too

I’m swinging a bit lower end for MBY because I’m lower than most (maybe 750-900) but I should still pull at least 4-6 without much of a sweat before any junk mixes in if it gets here 

[snywx]

8 minutes ago, crossbowftw3 said:

I’m swinging a bit lower end for MBY because I’m lower than most (maybe 750-900) but I should still pull at least 4-6 without much of a sweat before any junk mixes in if it gets here 

I like the Rock Hill area for this one. 12+ there

[crossbowftw3]

2 minutes ago, snywx said:

I like the Rock Hill area for this one. 12+ there

Couldn’t say I’d be shocked at that outcome since my ultimate results of any storm always differ wildly in these mixed bag situations as opposed to Rock Hill/MSV/what have you given the 300-400+ elevation changes in the matter of roughly 30 miles between where I am and those locations 

[snywx]

10 minutes ago, crossbowftw3 said:

Couldn’t say I’d be shocked at that outcome since my ultimate results of any storm always differ wildly in these mixed bag situations as opposed to Rock Hill/MSV/what have you given the 300-400+ elevation changes in the matter of roughly 30 miles between where I am and those locations 

Rock hill, Yankee lake, MSV all sit above 1500’ what a weenie location lol

[crossbowftw3]

3 minutes ago, snywx said:

Rock hill, Yankee lake, MSV all sit above 1500’ what a weenie location lol

Should be quite easy for those three to remain all snow all the way through and get the double digits around here, but I’ll feel kinda high and dry if I do stay around 4-6” and those three do all make 12+

[HeadInTheClouds]

It's going to be very difficult to accumulate east of Hudson in the valley. I'm surprised Poughkeepsie is even that much. 

 

[wishcast_hater]

4 minutes ago, HeadInTheClouds said:

It's going to be very difficult to accumulate east of Hudson in the valley. I'm surprised Poughkeepsie is even that much. 

 

Hopefully the coastal low will form more south and east for us. NWS said that the GFS model has a bias of forming the storms farther south and east than the other models out there. That was in there discussion last night.

[North and West]

Let’s be happy for our friends who haven’t gotten a big storm recently who live up north in this forum.

I hope it materializes and that you guys enjoy it!


.

[HeadInTheClouds]

18 minutes ago, wishcast_hater said:

Hopefully the coastal low will form more south and east for us. NWS said that the GFS model has a bias of forming the storms farther south and east than the other models out there. That was in there discussion last night.

GFS is on it's own little island of misfit toys. It is still colder and hasn't backed down on totals at 12z but I'm not buying it. I think we see no more than an inch or 2. 

[HeadInTheClouds]

[snywx]

12z GFS continues to double down. I would cut those totals In half. I highly doubt anyone in the 84 corridor is seeing 12-20” lol

[IrishRob17]

5 minutes ago, snywx said:

12z GFS continues to double down. I would cut those totals In half. I highly doubt anyone in the 84 corridor is seeing 12-20” lol

And I would cut that in half.

[RU848789]

Hard to ignore the significantly colder 12Z NAM and GFS solutions relative to earlier runs.  Let's see if other models hop on board.  Not going to "save" the 95 corridor, but would have big implications for the Lehigh Valley, Poconos, NWNJ, and the Hudson Valley.  

 

 

 

[wishcast_hater]

20 minutes ago, RU848789 said:

Hard to ignore the significantly colder 12Z NAM and GFS solutions relative to earlier runs.  Let's see if other models hop on board.  Not going to "save" the 95 corridor, but would have big implications for the Lehigh Valley, Poconos, NWNJ, and the Hudson Valley.  

 

 

 

That would be great for me. At this point I would take anything other than rain. 

[gpsnavigator]

Sparta, NJ (Sussex County).   Elevation 800'   Looks like I'm close, real close.  Could go either way with a 25 mile wobble in either direction.

[jm1220]

21 minutes ago, RU848789 said:

Hard to ignore the significantly colder 12Z NAM and GFS solutions relative to earlier runs.  Let's see if other models hop on board.  Not going to "save" the 95 corridor, but would have big implications for the Lehigh Valley, Poconos, NWNJ, and the Hudson Valley.  

 

 

 

I would bet big that sleet will mix in sooner than the GFS has especially I-84 and south and that ratios will be lower than 10-1 so I would use the Kuchera map if anything. Models last night were showing a warm push at 750mb or so which makes sense since winds are southerly at that level. NAM is almost always closer to correct than the GFS at finding the warm layer. But there’ll definitely be areas with some elevation (over 1000’) that get crushed with this. The NAM getting colder is a good sign. 

[cleetussnow]

R/S line is about 15 miles north of me on the NAM and about 4 miles south of me on the GFS.  I am not optimistic as a modelled battleground is usually south of the actual battleground.  I am just north of HPN so right around there is my AO.    

[hudsonvalley21]

1 hour ago, snywx said:

12z GFS continues to double down. I would cut those totals In half. I highly doubt anyone in the 84 corridor is seeing 12-20” lol

Being on the east side of the county and at 125’ in elevation, I’m looking at 1-2” before the change over to rn. Anything over that is a bonus. Just my take.  

[HeadInTheClouds]

12z Euro at 10:1. Kuchera map is not available on free Pivotal Weather so cut these amounts in half for our area. 

 

[jm1220]

Wow at the N Catskills. They’ll probably get smoked on that easterly flow upslope. I definitely believe there could be 20” amounts there. Unfortunately much of the Hudson Valley probably goes to rain/sleet quickly and gets shadowed to some extent. 

[Brian5671]

29 minutes ago, jm1220 said:

Wow at the N Catskills. They’ll probably get smoked on that easterly flow upslope. I definitely believe there could be 20” amounts there. Unfortunately much of the Hudson Valley probably goes to rain/sleet quickly and gets shadowed to some extent. 

Most ski areas will do well-they need the early season snow for sure...

[HeadInTheClouds]

46 minutes ago, jm1220 said:

Wow at the N Catskills. They’ll probably get smoked on that easterly flow upslope. I definitely believe there could be 20” amounts there. Unfortunately much of the Hudson Valley probably goes to rain/sleet quickly and gets shadowed to some extent. 

Yeah, NWS Albany was talking about downsloping and shadowing in the valleys. I'll be happy with 2 inches before changeover. 

[HeadInTheClouds]

Winter Storm Watch up in Orange county, obviously higher amounts expected in NW section and higher elevations. 

[crossbowftw3]

Warning here now for 6-9” and maybe some ice, 18z HRRR while out of range depicts pretty well how I’d expect the elevation game to unfold. 

 

See the blue hole in Sullivan? That’s about where I am. Always having wildly different outcomes on winter storms than the other 80% above 1200’ compared to my 700-900’. I want to get to those elevations minimum for the goodies, otherwise I’m looking at 32-34 degree 4-6” slop 

[snywx]

51 minutes ago, HeadInTheClouds said:

Winter Storm Watch up in Orange county, obviously higher amounts expected in NW section and higher elevations. 

Yeah they finally pulled the trigger. Meanwhile the 18z GFS continues to double down on a big time event for the 84 corridor