Snow Potential Dec 26-27

[sussexcountyobs]

Clear. 15.8F

[TriPol]

23 in the Bronx. About 12 hours 'til showtime.

[Snowlover11]

6z NAM

&

Latest HRRR

[nightknights]

Sure would like to see a 25-50 mile  slide south

[eduggs]

The 6z HRRR and esp NAM should concern snow lovers from NYC south and west. The surface and mid-level low centers continue to tick further northeast. That's getting heavy snow into SVT now, and even BOS on the NAM. That's a yellow caution flag at minimum.

On the other hand, the 6z RGEM held steady or even ticked a hair south and wetter locally.

[SnoSki14]

5 minutes ago, eduggs said:

The 6z HRRR and esp NAM should concern snow lovers from NYC south and west. The surface and mid-level low centers continue to tick further northeast. That's getting heavy snow into SVT now, and even BOS on the NAM. That's a yellow caution flag at minimum.

On the other hand, the 6z RGEM held steady or even ticked a hair south and wetter locally.

GFS also held its ground 

[WeatherGeek2025]

Just now, SnoSki14 said:

GFS also held its ground 

it went south a little

[EasternLI]

[eduggs]

ICON looks slightly better than 0z. GFS and RRFS look very similar to their previous runs. All solid for most of the area! Gotta watch the radar, obs, and HRRR today to see if the northeast shift is real or not.

[SnoSki14]

9 minutes ago, eduggs said:

The 6z HRRR and esp NAM should concern snow lovers from NYC south and west. The surface and mid-level low centers continue to tick further northeast. That's getting heavy snow into SVT now, and even BOS on the NAM. That's a yellow caution flag at minimum.

On the other hand, the 6z RGEM held steady or even ticked a hair south and wetter locally.

Just given the cold dense dry air in place I would give a lot more credence to the GFS/RGEM than the northern models. 

[jm1220]

6 minutes ago, eduggs said:

The 6z HRRR and esp NAM should concern snow lovers from NYC south and west. The surface and mid-level low centers continue to tick further northeast. That's getting heavy snow into SVT now, and even BOS on the NAM. That's a yellow caution flag at minimum.

On the other hand, the 6z RGEM held steady or even ticked a hair south and wetter locally.

If near warning snow is making it to Boston, a chunk of what my backyard gets even will likely be sleet. I know other models are colder but we’ve seen them verify too cold in these type events. It’s clipper like but behaving like a SWFE with overrunning into cold air. Like that or not, take what you will but historically SWFE is not good for NYC. It’s not your typical SWFE for sure but these overrunning deals so often pull the rug out by trending north at the end. We’re at the point where we just have to see what happens. Hopefully we get good precip that doesn’t shoot over way NE and we’re not waiting for hours in the city as it warms in the mid levels. 

[eduggs]

The 8z HRRR directs the best snow into the Catskills and ENY through the end of its run. There is still locally a few-hour burst of mod-heavy snow and probably a little more to come beyond its 18 hour range, but the northeast shift continues. That's pushing a bit of a dryslot into SNY and PA.

I don't like seeing the HRRR seemingly shift towards the NAM. Can't wait to see that trend reverse. Most other guidance looks solid however.

[eduggs]

The 9z RAP also shifted heavy snow into C/ENY and SVT (like the HRRR/NAM) and brought mixing into the southern tier of NY. A surface low in WNY is not ideal. We still do great locally, but I don't like seeing more snow in ALB than BGM.

[eduggs]

UK held or slight improvement.

The trend towards shifting the lows northeast and delaying their decay/shunt south is leading to a more north-south oriented snow accumulation distribution as it pushes moisture into the damned cold air. There will likely be a snowfall max now in ENY with excellent ratios. But if we can hold off mixing, our QPF might get a boost leading to a 2nd max further south near NYC or the HV but with lower (still decent) ratios.

[steve392]

What time we looking at first flakes around nyc? 

[Snowlover11]

1 minute ago, steve392 said:

What time we looking at first flakes around nyc? 

3-6pm

[TriPol]

6 am. 10 hours ETA. Let's do this. I'm pumped.

[Volcanic Winter]

Such an odd track diving southeast, enjoy the snow guys! At 21F now, stinks with solid cold in place I won’t be able to get more out of this - but yeah, odd track and it’s expanded north. Nice storm though!

[MJO812]

1 hour ago, SnoSki14 said:

Just given the cold dense dry air in place I would give a lot more credence to the GFS/RGEM than the northern models. 

Agree

Nam is still an outlier

[bluewave]

15 minutes ago, MJO812 said:

Agree

Nam is still an outlier

This storm will be the test for whether they can finally discontinue the NAM. The NAM was the only model which could see the warm nose at 850 mb to 750 mb. None of the other models were very good at this.

The NAM has sleet mixing in around EWR-NYC-LGA-JFK. But keeps it all snow from Suffolk NW back into SW CT and interior SE NY.

So out of respect for the NAM, I will go 3-5” around EWR-NYC-LGA-JFK and 5-8” Northern Nassau to Suffolk.

[MJO812]

11 minutes ago, bluewave said:

This storm will be the test for whether they can finally discontinue the NAM. The NAM was the only model which could see the warm nose at 850 mb to 750 mb. None of the other models were very good at this.

The NAM has sleet mixing in around EWR-NYC-LGA-JFK. But keeps it all snow from Suffolk NW back into SW CT and interior SE NY.

So out of respect for the NAM, I will go 3-5” around EWR-NYC-LGA-JFK and 5-8” Northern Nassau to Suffolk.

I like your amounts although I would just go 4-8 inches. 

[SomeguyfromTakomaPark]

Newest HRRR looks nice to me, heaviest banding right through nyc metro.

[weatherpruf]

don't. know what's gonna happen but i do know sleet is a persistent little mother, and often rears its head well before we want. that said, there is disagreement even among the pros how much of this will happen and when. so let's just let this one ride and hope we can get some good season's greetings photos for next year's card....got a daughter commuting to somerset in her 2009 impala, her first time working with snow on the way; hope she can leave work early before 287 is a mess; retired now, and worry about loved ones.....be safe all, and let's hope for some wintry wonderland photo ops. we get enough winters without them....

[donsutherland1]

The overnight guidance has reaffirmed the idea of a 4"-8" snowfall in and around the New York City area. Much of the snow could fall during a 3-hour stretch during the evening when snowfall rates approach or reach 1" per hour. Parts of the Hudson Valley and western Connecticut could see even more intense hourly snowfall rates.

During the height of the storm, snow-to-liquid ratios could be 11:1-12:1 in the region. Ratios will fall as the mid-level warms and will likely be around 8:1 late in the storm. The storm could still end with some sleet in and around New York City. The risk of sleet increases the farther south and west one goes. 

The consistency of the quality guidance in focusing the heaviest snows on an area that covers New York City, the Hudson Valley, and western Connecticut provides confidence that this region will experience a significant snowfall. In terms of the EPS and GEFS, 90.2% of ensemble members show 4" or more snow for New York City. Just 1 member has 2". The range between lowest and highest amounts is 2"-8" on the ensembles. 

A much larger share of precipitation will fall as freezing rain and/or sleet farther south. Philadelphia will likely pick up a coating  to 2" of mainly sleet. The lower part of that range is probably more likely than the upper end. In contrast, Boston will see the heaviest snows pass to its south. A 1"-3" snowfall is likely there.

If Boston and Philadelphia see less than 2" of snow while New York City picks up 6" or more, that would be a very infrequent outcome. Since 1890, 175 storms have brought 6" or more snow to New York City, but just five saw both Boston and Philadelphia pick up less than 2" of snow. The most recent such storm occurred during February 26-27, 1991 when Boston saw 0.7", New York City picked up 8.9", and Philadelphia received 0.1".

All said, New York City and its nearby suburbs remain in line for a 4"-8" snowfall. The snow should start overspreading the region during the mid- or late afternoon and work across Long Island during the early evening.

 

[TriPol]

25 minutes ago, weatherpruf said:

don't. know what's gonna happen but i do know sleet is a persistent little mother, and often rears its head well before we want. that said, there is disagreement even among the pros how much of this will happen and when. so let's just let this one ride and hope we can get some good season's greetings photos for next year's card....got a daughter commuting to somerset in her 2009 impala, her first time working with snow on the way; hope she can leave work early before 287 is a mess; retired now, and worry about loved ones.....be safe all, and let's hope for some wintry wonderland photo ops. we get enough winters without them....

I'll never forget the Valentines Day Storm of 2007. I had so much hope for that. So much f'ing sleet.

[ForestHillWx]

15/4 out my way in this part of western Morris County.

Nearly every model has the sharp cut-off with the good totals to my immediate southwest, so my expectations are in line.

I would note, to my untrained eye, the CAD isobars seem primed to put up a good fight with whatever warmth is coming; keep the faith for those north/east of me.  

[ILoveWinter]

Queue the “the airmass is cold” posts, I’ll start: damn it’s cold outside even in Manhattan! 20/6