Extreme Cold, Snow & Sleet: SECS 1/24 - 1/26

[MJO812]

9 degrees here

Expecting 6-12 here

[Prue11]

19 minutes ago, sussexcountyobs said:

And of course on the coldest day of the year, pre snowstorm, my heat upstairs isn't working. I think it's the circulator pump?

Check the pump if it’s cold while the heat is running it’s toast 

[SACRUS]

 

Positive possibilities

Front end overrunning over performs (>0.6) of the total 1.0 - 1.4 QPF at 12:1 or 15:1 ratios and the mix / sleet is light precip.  That first 6 - 8 hours is key to the front end WAA snows.

 

Snowfall from 0.65" Liquid (LE)

Snow Ratio	Snowfall
12:1	7.8 inches
15:1	9.8 inches

 

[snowman19]

7 minutes ago, EastonSN+ said:

You were right on this one. Starting to think closer to 6 before the flip but will range 6 to 10 in case the initial thump is impressive. Is that what your thoughts are?

The initial front end thump is definitely going to be impressive. That’s locked in, I think the only remaining question is, when does the changeover to sleet with the warm nose then dry slot happen? As a sweeping generality, I’d say 6-10 in the NYC metro area (including the immediate north and west suburbs) before the changeover/dry slot

[Brian5671]

On the edge of the sleet line here but I think it gets here eventually.   10-12 before that however at least taking a blend of the models

[sussexcountyobs]

11 minutes ago, Prue11 said:

Check the pump if it’s cold while the heat is running it’s toast 

Pump is hot. My boiler guy should be here within a half hour.

[WeatherGeek2025]

31 minutes ago, sussexcountyobs said:

And of course on the coldest day of the year, pre snowstorm, my heat upstairs isn't working. I think it's the circulator pump?

Grab a small wrench and tap it numerous times. Like actually hit it

[weathermedic]

Good write up (as usual) with the morning AFD out of Upton:

A major winter storm will impact the region Sunday into at least
early Monday. A Winter Storm Warning Remains in effect for the
entire area.

Arctic air has settled over the area courtesy of a sprawling
1048 mb high pressure over the northern plains. This high
pressure will settle over New England tonight as a winter storm
materializes over the southeastern US.

Low pressure will develop over the south and be forced to track
around the deep cold air damming signature east of the
Appalachians tonight, with secondary low development taking
place along the Middle Atlantic coast on Sunday. This low
pressure will then deepen as it tracks towards the Long Island
coast late Sunday into Sunday night before shifting offshore on
Monday.

The main uncertainty with the system continues to revolve around
the timing of potential mixing with sleet for the
southern/coastal portion of the region Sunday evening. The model
guidance is in overall agreement on the key pieces with the
winter storm, but differ slightly on the northward extent and
timing of a warm nose around 750 mb. Generally took a blend of
partial thicknesses from the GFS, ECMWF, NAM, and RGEM Sunday
evening. Most of the guidance has settled on any potential
wintry mix occurring around or just after 00z Monday. The NAM
is the most aggressive and quickest with the warm nose (sometime
mid to late afternoon) and wanted to at least blend its
thicknesses in case the warm nose comes in a bit faster than
currently expected, which has happened in past events.

Snow will quickly develop from south to north across the area
Sunday morning as the region lies underneath an intense polar
jet streak lifting into southeast Canada. The snow will fall
into arctic air with surface temperatures only in the low to
mid teens. This is a bit unusual for the area as most snow
events over the Tri-State occur with temperatures in the 20s or
low 30s. The snow will quickly accumulate as the intensity
picks up through the morning. Mid level thermal forcing will
increase over the area, especially heading into the afternoon.
The 850-700 mb frontogenesis is impressive and the overall deep
layer of vertical velocities over the area strongly support
heavy snow over the region in the afternoon. Only a slight
increase in temperatures is expected in the afternoon, except
the southern half of the area where temperatures rise into the
mid 20s.

As the warming in the middle levels continues, the chance for a
mix with sleet near the coast increase sometime late in the
afternoon or evening. It needs to be emphasized that the
overall impacts will not change and significant snow will occur
before any wintry mix. There is a possibility the heavy
snowfall rates will be able to hold back the warm nose just
enough or create an isothermal layer on the 0C isotherm to
prolong heavy snow for even just an hour two. The 00z HREF
indicated several hours of over a 60 percent chance of greater
than 1 inch per hour rates, and even has a few hours over 80
percent. The probability for greater than 2 inches per hour on
the HREF in the afternoon/early evening ranges from 20 to 40
percent.

The guidance also offers impressive QPF values between 18z
Sunday and 00z Monday with potential of at least a half inch
liquid, giving more confidence there will be heavy snowfall
over the area.

A few lightning strikes cannot be ruled out in the heaviest
bands with the impressive dynamics aloft and deep moisture being
lifted over the low level arctic air.

The strong mid level frontogenesis lifts northeast between
00-06z Monday and this should serve to gradually reduce precip
rates. There may also be drying aloft, which will start to
reduce snowfall rates where it remains all snow. The southern
half of the area should see a wintry mix of sleet, potentially
mixed with snow if the warm nose is not as deep. There is also a
chance for some light freezing rain and a light glaze of ice as
the drying aloft occurs, cutting off snow growth along with the
thinning of the depth of the low level cold air. This may also
be dependent on how close the low pressure ends up to Long
Island. The consensus of the modeling keeps the low just south
and east of Long Island, but if it were to end up closer to the
shore, some parts of eastern Long Island could briefly rise
above freezing with light plain rain briefly possible.

The system starts pulling away from the area late Sunday night
into Monday morning. Some bands of light snow may return as the
trailing upper trough approaches and the thermal profiles become
colder heading into Monday. Probabilities for precip decrease
significantly Monday afternoon and there is potential anything
that falls may just be flurries.

Snowfall totals are largely consistent with the previous
forecast ranging from around 10 inches near the coast and around
16 inches well inland. The potential of sleet is included in
these totals for areas that may see a mix or a full changeover.

SLRs are tricky with this event as the arctic air mass supports
a higher ratio (around or just above 15:1), especially early in
the event. The increasing moisture aloft and warmer air in the
middle levels will likely lower ratios to 12-14:1 and will drop
further with any mixing in the evening towards the coast.

As noted above, snowfall rates of 1-2 inches per hour are
expected in the afternoon and early evening. Winds will pick up
in the afternoon and evening, especially near the coast and
could create near white-out conditions/near blizzard conditions
with winds gusting 30 to 40 mph at times. A mix or change to
sleet will reduce this potential as visibilities would not be as
low.

[Snowlover11]

6z Euro cant post the image, stupid file is too big.

But its either right or going to burn.

[Stormlover74]

4 minutes ago, Snowlover11 said:

6z Euro cant post the image, stupid file is too big.

But its either right or going to burn.

It didn't look that different from the other models

[EasternLI]

8 minutes ago, weathermedic said:

Good write up (as usual) with the morning AFD out of Upton:

A major winter storm will impact the region Sunday into at least
early Monday. A Winter Storm Warning Remains in effect for the
entire area.

Arctic air has settled over the area courtesy of a sprawling
1048 mb high pressure over the northern plains. This high
pressure will settle over New England tonight as a winter storm
materializes over the southeastern US.

Low pressure will develop over the south and be forced to track
around the deep cold air damming signature east of the
Appalachians tonight, with secondary low development taking
place along the Middle Atlantic coast on Sunday. This low
pressure will then deepen as it tracks towards the Long Island
coast late Sunday into Sunday night before shifting offshore on
Monday.

The main uncertainty with the system continues to revolve around
the timing of potential mixing with sleet for the
southern/coastal portion of the region Sunday evening. The model
guidance is in overall agreement on the key pieces with the
winter storm, but differ slightly on the northward extent and
timing of a warm nose around 750 mb. Generally took a blend of
partial thicknesses from the GFS, ECMWF, NAM, and RGEM Sunday
evening. Most of the guidance has settled on any potential
wintry mix occurring around or just after 00z Monday. The NAM
is the most aggressive and quickest with the warm nose (sometime
mid to late afternoon) and wanted to at least blend its
thicknesses in case the warm nose comes in a bit faster than
currently expected, which has happened in past events.

Snow will quickly develop from south to north across the area
Sunday morning as the region lies underneath an intense polar
jet streak lifting into southeast Canada. The snow will fall
into arctic air with surface temperatures only in the low to
mid teens. This is a bit unusual for the area as most snow
events over the Tri-State occur with temperatures in the 20s or
low 30s. The snow will quickly accumulate as the intensity
picks up through the morning. Mid level thermal forcing will
increase over the area, especially heading into the afternoon.
The 850-700 mb frontogenesis is impressive and the overall deep
layer of vertical velocities over the area strongly support
heavy snow over the region in the afternoon. Only a slight
increase in temperatures is expected in the afternoon, except
the southern half of the area where temperatures rise into the
mid 20s.

As the warming in the middle levels continues, the chance for a
mix with sleet near the coast increase sometime late in the
afternoon or evening. It needs to be emphasized that the
overall impacts will not change and significant snow will occur
before any wintry mix. There is a possibility the heavy
snowfall rates will be able to hold back the warm nose just
enough or create an isothermal layer on the 0C isotherm to
prolong heavy snow for even just an hour two. The 00z HREF
indicated several hours of over a 60 percent chance of greater
than 1 inch per hour rates, and even has a few hours over 80
percent. The probability for greater than 2 inches per hour on
the HREF in the afternoon/early evening ranges from 20 to 40
percent.

The guidance also offers impressive QPF values between 18z
Sunday and 00z Monday with potential of at least a half inch
liquid, giving more confidence there will be heavy snowfall
over the area.

A few lightning strikes cannot be ruled out in the heaviest
bands with the impressive dynamics aloft and deep moisture being
lifted over the low level arctic air.

The strong mid level frontogenesis lifts northeast between
00-06z Monday and this should serve to gradually reduce precip
rates. There may also be drying aloft, which will start to
reduce snowfall rates where it remains all snow. The southern
half of the area should see a wintry mix of sleet, potentially
mixed with snow if the warm nose is not as deep. There is also a
chance for some light freezing rain and a light glaze of ice as
the drying aloft occurs, cutting off snow growth along with the
thinning of the depth of the low level cold air. This may also
be dependent on how close the low pressure ends up to Long
Island. The consensus of the modeling keeps the low just south
and east of Long Island, but if it were to end up closer to the
shore, some parts of eastern Long Island could briefly rise
above freezing with light plain rain briefly possible.

The system starts pulling away from the area late Sunday night
into Monday morning. Some bands of light snow may return as the
trailing upper trough approaches and the thermal profiles become
colder heading into Monday. Probabilities for precip decrease
significantly Monday afternoon and there is potential anything
that falls may just be flurries.

Snowfall totals are largely consistent with the previous
forecast ranging from around 10 inches near the coast and around
16 inches well inland. The potential of sleet is included in
these totals for areas that may see a mix or a full changeover.

SLRs are tricky with this event as the arctic air mass supports
a higher ratio (around or just above 15:1), especially early in
the event. The increasing moisture aloft and warmer air in the
middle levels will likely lower ratios to 12-14:1 and will drop
further with any mixing in the evening towards the coast.

As noted above, snowfall rates of 1-2 inches per hour are
expected in the afternoon and early evening. Winds will pick up
in the afternoon and evening, especially near the coast and
could create near white-out conditions/near blizzard conditions
with winds gusting 30 to 40 mph at times. A mix or change to
sleet will reduce this potential as visibilities would not be as
low.

This part, right here  :

A few lightning strikes cannot be ruled out in the heaviest
bands with the impressive dynamics aloft and deep moisture being
lifted over the low level arctic air.

[Prue11]

15 minutes ago, sussexcountyobs said:

Pump is hot. My boiler guy should be here within a half hour.

Good luck let is know how it goes maybe an air pocket 

[WeatherGeek2025]

7 minutes ago, Snowlover11 said:

6z Euro cant post the image, stupid file is too big.

But its either right or going to burn.

is it better for the city?

[SACRUS]

 

atest 12z (1/24) HRR has snow between 3AM and 6AM Sunday

 

 

 

 

 

 

[SACRUS]

Still all snow by 11AM

[oceanctyguy]

42 minutes ago, BoulderWX said:

Mt Holly finally coming around. Slashed totals big time which is the right call - just took a while. 

Even with the lower totals still think 8-12 all the way down through Ocean County where I am is excessive. Will find out soon enough.

[Prue11]

2 minutes ago, SACRUS said:

Still all snow by 11AM

I would hope it’s still snow by 11am, if it wasn’t we’d be screwed 

[SACRUS]

 

 

Still holding onto snow by 2PM

[SACRUS]

 

Mixing by 3PM just south of the city with 0.6 fallen as snow at 12:1 ratio 7.5 inches

[SACRUS]

By 4pm mixing / sleet just about into the City 

 

[SACRUS]

 

HRR has snow line fighting back at 6PM

 

[Stormlover74]

1 minute ago, SACRUS said:

By 4pm mixing / sleet just about into the City 

 

Next frame it pushes back south again. But its the long range hrrr so who knows

[Wannabehippie]

1 minute ago, SACRUS said:

By 4pm mixing / sleet just about into the City 

 

Logically this doesn't make sense, interior NJ has sleet, but NYC and LI is all snow? 

[SACRUS]

Just now, Wannabehippie said:

Logically this doesn't make sense, interior NJ has sleet, but NYC and LI is all snow? 

HRRR Fwiw does this - just another piece of guidance to explore. Out of the more useful range.

[donsutherland1]

Despite what seemed like a lengthy funeral oration for a storm that had yet to arrive following the 1/24 6z NAM and GFS runs, things still seem reasonably on course for a significant snowfall across the New York City region.

1) The models have been shifting about. One shouldn't focus only on the best or worst models.

2) The UKMET has slowly started paring back its precipitation hole. Some have affectionately nicknamed it "Crazy Uncle" for its occasional eccentricities. The 1/24 0z ECMWF improved over the 1/23 12z run.

3) 700 mb frontogenic forcing looks to be explosive for three and maybe four hours at a time when snow growth will be ideal. Four hours of 1"-2" per hour snowfall rates would yield 4"-8"; 0.60" QPF at 12:1-13:1 ratios would yield 7.2"-7.8". Take the low figures and that's probably the floor.

Overall, New York City and nearby areas remain in line for 6"-12" of snow and sleet. Areas to the south and east of New York City could see 4"-8" amounts (even farther south beyond the New York City area, places like Atlantic City should see 3"-6"). General 12"-18" amounts are likely well north and west of New York City, most likely in parts of northeastern Pennsylvania (Pike County, Lackawanna County), Orange County, Dutchess County, and Sussex County.  

[Stormlover74]

3 minutes ago, Wannabehippie said:

Logically this doesn't make sense, interior NJ has sleet, but NYC and LI is all snow? 

Typically the sleet line will move up from the southwest rather than south or southeast 

[jm1220]

5 minutes ago, Wannabehippie said:

Logically this doesn't make sense, interior NJ has sleet, but NYC and LI is all snow? 

Closer to the high pressure/cold source region. I'm confident 80% of us mix at some point. The I-84 crew will probably avoid it-I hope anyway.

[nycsnow]

Just now, jm1220 said:

Closer to the high pressure/cold source region. I'm confident 80% of us mix at some point. The I-84 crew will probably avoid it-I hope anyway.

Hrrrrr just shows though how hanging on even for an extra couple hours is huge. Fun times ahead can be a lot of positive surprises and obv negative ones as well

[jm1220]

1 minute ago, nycsnow said:

Hrrrrr just shows though how hanging on even for an extra couple hours is huge. Fun times ahead can be a lot of positive surprises and obv negative ones as well

The heavy rates will be key. If those shred up or let up the warm air will advance fast. We saw this in last Feb's SWFE and back in Dec. 

[SACRUS]

 

1/24 12 NAM next up