January 6-7, 2024 | NE / Mid-Atlantic Winter Storm

[RTC3-LAST CHANCE]

2 minutes ago, Rickrd said:

YO!

Texted you that this never ending 7 day weekend pattern has produced lots of blow up  , slow movers. Does it get caught in the block in time?? Let her hit her toes on land first.

[Penn State]

GEFS Members 

[Penn State]

UK Totals.. Which look more robust. Maybe a sign of the Euro later? 

[so_whats_happening]

47 minutes ago, Penn State said:

All in all.. not bad.. Did you notice how it hung around though?

It is the second piece of energy that has been getting held back. Kinda just extends the precip around the area wouldn't it be something if the first wave kinda just comes through and allows a the secondary system to be something.

[Rickrd]

0z Euro a tick slower this run. 

[Rickrd]

0z euro hr 96. Incoming

[Rickrd]

Hr 105

[Rickrd]

He 111

[mikeysed]

Ursula where are the children. A bomb is incoming

[Rickrd]

0z Euro a nice hit for many!

[TheComet]

1 hour ago, Rickrd said:

0z Euro a nice hit for many!

So Euro on the northern and GFS on the southern side of envelope. Where have I seen this play before?

[MaineJay]

ECMWF trend. It is pretty remarkable to see how the models missed the shortwave in the 4 corners area, seemed to be a blind spot for all the centers.  We've also introduced a number of smaller, northern stream components, some of which *could* play a role.

  We do often see a storm turn into multiple waves, not necessarily in this fashion, but there are some scenarios when trailing energy can prolong a lighter event, a la ULL pulling through, or some inverted troffiness.

While this won't have seismic shifts, they'll still be rearranging the deck chairs a bit as we close in on the iceberg, err I mean snow storm. Kidding! Gotta have a sense of humor round here, and don't take anything too serious or personal.

Our system is just now impinging on the left coast 

This, is where that mischievous 4 corners energy current resides.

It's been a tough winter, a couple/few in a row for many. Just having something to track has been a pleasure.

  Seeing so many recognizable handles, new members, just the activity level had been enjoyable.  When we all started out trying to maintain the community, what, almost 3 years ago now? And like 3 years before that when accuforums locked the doors on us, there was so much uncertainty.  Still is. But it feels like we are building a great group.

  A huge appreciation to the staff and supporters for all the work and your presence.  We run on the generosity of our members, whether that be financial or in the contributions made to the discussion.  Temporary break to express my gratitude.

Now back to your regularly scheduled program.

[metsfan78]

24 minutes ago, MaineJay said:

ECMWF trend. It is pretty remarkable to see how the models missed the shortwave in the 4 corners area, seemed to be a blind spot for all the centers.  We've also introduced a number of smaller, northern stream components, some of which *could* play a role.

  We do often see a storm turn into multiple waves, not necessarily in this fashion, but there are some scenarios when trailing energy can prolong a lighter event, a la ULL pulling through, or some inverted troffiness.

While this won't have seismic shifts, they'll still be rearranging the deck chairs a bit as we close in on the iceberg, err I mean snow storm. Kidding! Gotta have a sense of humor round here, and don't take anything too serious or personal.

Our system is just now impinging on the left coast 

This, is where that mischievous 4 corners energy current resides.

It's been a tough winter, a couple/few in a row for many. Just having something to track has been a pleasure.

  Seeing so many handles, new members, just the activity level had been enjoyable.  When we all started out trying to maintain the community, what, almost 3 years ago now? And like 3 years before that when accuforums locked the doors on us, there was so much uncertainty.  Still is. But it feels like we are building a great group.

  A huge appreciation to the staff and supporters for all the work and your presence.  We run on the generosity of our members, whether that be financial or in the contributions made to the discussion.  Temporary break to express my gratitude.

Now back to your regularly scheduled program.

Thank you to all who work behind the scenes. I have learned so much from all of you over the years dating back to the accu forums. you wealth of knowledge and the time it takes to keep this site running is greatly appreciated

[MaineJay]

GYX

Quote

Dry conditions will continue into Saturday, but clouds will increase
through the day as moisture increases out ahead of a shortwave
trough moving across the OH/TN Valleys and toward the Mid-Atlantic.
As this occurs, models continue to show low pressure developing off
the Mid-Atlantic coast and moving to the E or ENE across the western
Atlantic into Sunday night, which could bring a round of snow to the
area Saturday night and into the day Sunday. There still remains a
lot of uncertainty with this system as it will be battling high
pressure and drier air to the north. The GFS has shown poor run to
run consistency with QPF/snow amounts and how far north
precipitation is able to reach with the latest 00Z run really
backing off on amounts from what the 12Z was showing yesterday. The
ECMWF on the other hand has been more consistent with a deeper low
and slightly farther north than the GFS, which would bring more
QPF/snow. This is still into day 4-5 of the forecast so it`s still
too early for amounts, but the better chance for snow and
accumulating snow continues to be across southern NH with increasing
uncertainty the farther north one goes.

 

[MaineJay]

BOX

Quote

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...

Highlights

* Dry Thu Night through much of Sat. Will be a bit breezy Thu Night
  into Fri AM.

* Unsettled late Sat through Sun. Still a considerable amount of
  uncertainty with how things evolve. So, specific details are still
  hazy at this point.

* Drier Mon into Tue. Active pattern continues as we head into mid
  next week with more impactful weather possible.

Thursday Night through Saturday...

A trough will lift from New England Thu night to just offshore of
Nova Scotia by Fri AM. Behind the trough a ridge builds from the
Mississippi River Valley into the Great Lakes Region by early Fri.
The ridge builds into the eastern Great Lakes/Mid Atlantic by late
Fri and into New England on Sat. High pressure nudges in from the OH
Valley Thu night and Mid Atlantic on Fri. The high shifts offshore
on Sat.

Generally anticipating dry and quiet weather through this period.
Did make some adjustments to wind speeds/gusts Thu night into early
Fri. The pressure gradient remains tight due to the departing system
and incoming high. Should not be too difficult to mix down the 25-40
kt 925 hPa NNW to NW low level jet with colder air advecting in.
Adjusted our wind speeds/gusts to match this. Given the stronger
winds didn`t nudge temps down too much Thu night into early Fri, but
should have fairly widespread lows in the teens across the
region. Will be a bit milder Fri night into Sat as mid/high
clouds are increasing despite the lighter winds. Lows in the
upper teens to mid 20s. Near seasonable temperatures expected
Fri and Sat.

Saturday Night through Sunday Night...

Still the main focus and possible next shot for impactful weather
across southern New England. As was the case from earlier today and
last night there is a considerable amount of uncertainty this far
out. A trough or series of troughs lift in from the Mississippi
River Valley or Southern Plains later on Sat and Sun. A Miller-A
type low of some variety lifts toward southern New England.

Once again have leaned toward the NBM guidance given the significant
spread in the exact track and intensity of the system. At this point
there is little run to run and model to model consistency,
especially with respect to the intensity/track of the system. As
mentioned previously the energy associated with this system is still
located offshore of the Pacific Northwest under a split flow regime.
Guidance tends to have lower predictability in these scenarios, so
suspect we will continue to see these swings from run to run until
this feature moves onshore on Thu.

Diving a bit deeper into the details from the ensemble systems. The
latest GEFS guidance depicts a fair amount of spread, but has
trended further to the southeast from the previous run. All but 2
members are SE of the benchmark. The GEFS probabilities of QPF AOA
0.5 inches are now low to moderate (<10-40 percent), whereas the
previous run was solidly in the moderate range (30-60 percent).
Given this the plowable snowfall probs have also lowered. The EPS
guidance has trended weaker and further southeast from the prev run,
but still with considerable spread. The EPS still solidly with
moderate to high probs (40-70+ percent) of AOA 0.5 inches of QPF.
Given the shift to the southeast probs have lowered slightly, but
the EPS is more consistent than the GEFS. The snowfall probabilities
have also lowered a bit. The GEPS is more tightly clustered to the
Cape/Islands with deeper lows and high probs (70-90+ percent) of 0.5
inches or greater and higher probs of plowable snowfall. Definitely
something we will need to continue to monitor, especially given
PWATs are roughly in the 75th the 90s percentile for this time of
year (between 0.5-0.75 inches) per SPC Sounding Climo for CHH. On
top of the precip could also have potentially strong to gusty winds
with winds roughly 2-3 STD above model climo per the NAEFS/EPS.

Have continued to stick with the NBM with solid likely to definite
PoPs at this point. Did not hone in on too much of the specifics for
ptypes and exact snowfall amounts given the system track is key for
hammering down these details and specific SLRs/impacts. Stay tuned
for future updates as confidence should grow as the week progresses.

 

[PA road DAWG]

Hanging on still 

[Wtkidz]

Snow to rain  or mix to rain.  Of course depends on track and thermal. Latest words from LWX (Sterling)

 

Quote

LONG TERM /SATURDAY THROUGH TUESDAY/...
A strong southern stream mid/upper-level trough over the Mid-South
Friday night quickly moves northeast as it phases into a flat trough
over the OH Valley/Mid-Atlantic on Saturday. At the surface, an
associated area of low pressure develops along the northern Gulf
Coast and very quickly moves across the Southeast states through
Saturday morning. The surface low becomes better organized as it
crosses eastern NC into far southeast VA, where it moves offshore
along the NC/VA border.

Precipitation overspreads the area from southwest to northeast
starting late Friday night into Saturday. Temperatures Friday night
are forecast to be below freezing for most of the area. However,
there is considerable uncertainty to the east of US-15 as easterly
winds advect in a warmer marine airmass and strong WAA ahead of the
surface low help to increase temps along/east of I-95. All that
being said, precipitation is likely to start out as snow west of US-
15 and a rain/snow mix along/east of US-15. As the morning
progresses, areas east of I-95 are most likely to transition to a
cold rain, with steady snow west of US-15, and a mix in between.

Having the surface high well to the north and weak onshore flow
proceeding the surface low are not generally favorable for
accumulating snow along I-95. Any chance to see higher snow totals
there will be dependent on higher precip rates and wet bulb effects
overcoming the marginal temperature profile.

Still, p-type is going to be highly sensitive to the track of the
low, with a tight rain-snow gradient likely. Significant snow
accumulations are most likely along/west of the Blue Ridge and
Catoctins. Where precip is more likely to be in the form of rain,
near and east of I-95, there is the potential for instances of
flooding. Continue to monitor the progress of this storm as the
weekend approaches.

The coastal low tracks northeast and away from the area Saturday
night, then a reinforcing upper traverses the area on Sunday. Some
lingering rain and snow showers possible during the first part of
Monday north of I-66 and west of the Blue Ridge, though conditions
dry out quickly in the afternoon. Upslope mountain snow showers
continue into Sunday night.

 

[MaineJay]

33 minutes ago, Wtkidz said:

Snow to rain  or mix to rain.  Of course depends on track and thermal. Latest words from LWX (Sterling)

 

 

We're in that time frame where it *feels* like we should be able to nail some things down, which, we know there will be some precipitation, but so many moving parts still.  There are some fairly small scale north stream features that seem tempting as to indulge in some fantasy, but are still being poorly handled.

 I mentioned a ways back when there appeared to be some consistency (good clustering) that the envelope might open up, with ensembles being under dispersed, and it feels like we are now working through that.

 Reading a few discos from various desks, and no one wants to touch the I95 corridor. Luckily, it's mostly a weekend event, so that should mitigate potential disruptions.

  I always phrase situation like this, if they models had been showing garbage, and we woke up and these models runs we all an improvement, many would be excited.

  We have some more time to ride the coaster.  I'm happy to ride along.

[Chris2333]

6 minutes ago, MaineJay said:

We're in that time frame where it *feels* like we should be able to nail some things down, which, we know there will be some precipitation, but so many moving parts still.  There are some fairly small scale north stream features that seem tempting as to indulge in some fantasy, but are still being poorly handled.

 I mentioned a ways back when there appeared to be some consistency (good clustering) that the envelope might open up, with ensembles being under dispersed, and it feels like we are now working through that.

 Reading a few discos from various desks, and no one wants to touch the I95 corridor. Luckily, it's mostly a weekend event, so that should mitigate potential disruptions.

  I always phrase situation like this, if they models had been showing garbage, and we woke up and these models runs we all an improvement, many would be excited.

  We have some more time to ride the coaster.  I'm happy to ride along.

I’ll touch the I95 corridor east…

 

there’s still time but I’ve seen this before that lovely rain/snow line loves to set up right around Philly just the dynamics of the coastal plain, etc. 

[1816]

4 minutes ago, MaineJay said:

We're in that time frame where it *feels* like we should be able to nail some things down, which, we know there will be some precipitation, but so many moving parts still.  There are some fairly small scale north stream features that seem tempting as to indulge in some fantasy, but are still being poorly handled.

 I mentioned a ways back when there appeared to be some consistency (good clustering) that the envelope might open up, with ensembles being under dispersed, and it feels like we are now working through that.

 Reading a few discos from various desks, and no one wants to touch the I95 corridor. Luckily, it's mostly a weekend event, so that should mitigate potential disruptions.

  I always phrase situation like this, if they models had been showing garbage, and we woke up and these models runs we all an improvement, many would be excited.

  We have some more time to ride the coaster.  I'm happy to ride along.

At least for  sw VA, this has all the hallmarks of our common kitchen sink storm. Zr, ip, drizzle, maybe a few flakes to start. Leading to a half inch crust at the end of the day. 

But stuff like the above gives me a little hope this might be one of the rare times where we see some unexpected last minute surprises happen. Not expecting it, but sounds like there's a lot of factors that could be difficult to model.  

[Wtkidz]

4 minutes ago, MaineJay said:

We're in that time frame where it *feels* like we should be able to nail some things down, which, we know there will be some precipitation, but so many moving parts still.  There are some fairly small scale north stream features that seem tempting as to indulge in some fantasy, but are still being poorly handled.

 I mentioned a ways back when there appeared to be some consistency (good clustering) that the envelope might open up, with ensembles being under dispersed, and it feels like we are now working through that.

 Reading a few discos from various desks, and no one wants to touch the I95 corridor. Luckily, it's mostly a weekend event, so that should mitigate potential disruptions.

  I always phrase situation like this, if they models had been showing garbage, and we woke up and these models runs we all an improvement, many would be excited.

  We have some more time to ride the coaster.  I'm happy to ride along.

I agree wholeheartedly.

 I often say a model has never once made the  weather.  If so they would never be wrong . 
 

Even this morning  the TV met  for the channel  I watch said that nothing is etched in stone  but they are 99.99% sure there is a storm coming and there will be precipitation . 

[Wtkidz]

O6z gfs national and regional views 
 

 

[PA road DAWG]

6z euro looks good. Better than 00z

[bigben89]

6 minutes ago, PA road DAWG said:

6z euro looks good. Better than 00z

Warmer?

[clm]

7 hours ago, Rickrd said:

0z Euro a nice hit for many!

 

6Z showing some consistency.  As much as I would love 13 inches of snow, I like to look at things realistically.  Between Euro taking a southerly track and GFS taking a northerly track, I would say Long Island gets 2 to 4 inches with some rain on the tail end of the storm.  I hope i'm wrong, but going by our mostly "warm" weather for December and not enough cold weather to make it stick immediately on the ground.