January 2026 Medium/Long Range Discussion

[IronTy]

5 minutes ago, GreyHat said:

In the news

 

Well taken literally I guess the headline is technically correct. Fails to mention that likely only the fish are likely to experience the snow...but technically it is "along East Coast". But clicks....

[Nomz]

2 minutes ago, Bob Chill said:

Vort maps are the best depiction of upper level energy and how it progresses. Vorticity is where all the good stuff is born. 

They tell pretty much the same story though, no?

[BristowWx]

Just now, Nomz said:

They tell pretty much the same story though, no?

Bottom one is easier in my view 

[hazwoper]

1 minute ago, Nomz said:

They tell pretty much the same story though, no?

The 500mb shows the vort maxes farrrrrr better.

[stormtracker]

Ok, extrapolating the NAM.  Looks like it's heading to anywhere from 0"-32"

[Nomz]

1 minute ago, hazwoper said:

The 500mb shows the vort maxes farrrrrr better.

both are at 500mb

[Nomz]

1 minute ago, stormtracker said:

Ok, extrapolating the NAM.  Looks like it's heading to anywhere from 0"-32"

IMO its worse than the euro

[Roger Smith]

True story about the number one analogue (March 2-3 1980) ... I was briefly working at Accu-weather to provide info about Canadian forecasting markets they might investigate, and their practice before a big storm was to have every forecaster draw up a map of personal snowfall estimates. Joe Bastardi of all people was in that group. I was drawing up maps for them, not providing forecasts, as I am not (was not) a degreed met, but I did draw up a forecast map and had it on a wall full of maps, and as I recall it had some pretty aggressive numbers in s.e. VA. They would then discuss all the maps ... The one person in the room who didn't say "oh that looks wrong" about my numbers was JB who I think had similar numbers on his map. You may recall, there had not been a lot of snow anywhere in the winter of 1979-80, I recall one moderate fall of about 6" across PA around Feb 10th maybe, otherwise bare ground especially further north, into the Great Lakes and northeast.

Anyway, we ended up busting low but had some influence on the group consensus. (well Joe did probably) The storm dropped well over 20" in Norfolk and Virginia Beach. I think it dropped 6 to 10 inches in the DC to Baltimore region and cut off around York, PHL and ACY. At the time it was record cold all over the eastern states, this would have been maybe Feb 29th 1980 or March 1st at the latest. It was an interesting two months of weather that followed, including a monster cutoff rainstorm over the northeast in early April and hot weather records from the mid-south to the east coast in late April. My time there ended on April 30th and I didn't maintain any connections but I have met some of the well-known people at Accu-wx and it is quite the hive of weather activity hidden away in the university town of State College PA. I recall Joe as a very friendly and gregarious person who often went balls to the wall compared to the more conservative senior forecasters, and was regarded as the rising star at the time. I think I was more of a setting moon. That's where I developed my interest in long-range forecasting, they were looking at getting into that area, and I participated in a couple of brainstorming sessions, once again, maps on a wall. I remember April 1980 coming out with huge positive anomalies over the south central U.S. in advance of a very hot summer. It all grabbed my interest and I began to look for methodologies that might work using date-shifted lunar analogues (a similar pattern where you refined the timing by shifting the dates to make lunar calendar similar ... I had worked out somehow that this is the method used by the Farmers Almanac, although they based their similar years on things like solar cycles and previous few months of anomalies. I worked this out by first figuring out what winter they were using and noticing a date shift that was explained by the moon's orbital cycles in that winter compared to 1979-80.

Was it worth it? Maybe not, it has been a voice in the wilderness sort of journey to say the least. But it is what it is. 

[hazwoper]

6 minutes ago, Nomz said:

both are at 500mb

Sorry meant the vorticity map.  Those maxes are far better at predicting where the energy is going.

[Bob Chill]

12 minutes ago, Nomz said:

They tell pretty much the same story though, no?

No they don't. They show 2 very different things. Vorticity (or Positive Vorticity Advection/PVA for our purposes with storms) shows rotation and lift in the atmosphere. This is caused by upper level level winds so the plots bear resemblance but they are not the same things at all. Vorticity maps should be visualized 3 dimensionally while wind maps are basically 2 dimensional.

[BristowWx]

I refuse to consider the NAM on Tuesday for Saturday.  I won’t do it.  

[Nomz]

1 minute ago, Bob Chill said:

No they don't. They show 2 very different things. Vorticity (or Positive Vorticity Advection/PVA for our purposes with storms) shows rotation and lift in the atmosphere. This is caused by upper level level winds so the plots bear resemblance but they are not the same things at all. Vorticity maps should be visualized 3 dimensionally while wind maps are basicslly 2 dimensional.

What do you mean by "Vorticity maps should be visualized 3 dimensionally"?

[TSSN+]

1 minute ago, Nomz said:

What do you mean by "Vorticity maps should be visualized 3 dimensionally"?

Ok take this discussion elsewhere 

[stormtracker]

Yeah, NAM is putrid attm

[Bob Chill]

6 minutes ago, Nomz said:

What do you mean by "Vorticity maps should be visualized 3 dimensionally"?

Think of it like this, you're flying on a jet into 150mph headwinds and it's nice and smooth. Would never know it's windy up there. That's the wind map. Suddenly your drink is on the ceiling and people are puking. That's the vorticity map

[Shad]

The NAM at 84 was actually great for the recent storm

[mitchnick]

1 minute ago, stormtracker said:

Yeah, NAM is putrid attm

Maybe, but the surface map looks like the Gfs and unlike other medium range models. Just sayin'.

[Ephesians2]

1 minute ago, mitchnick said:

Maybe, but the surface map looks like the Gfs and unlike other medium range models. Just sayin'.

That's from 12z NAM

Not like it matters, but 18z NAM looks east in its fantasy range

[batmanbrad]

part of afternoon AFD from Sterling - still keeping everything on the table while pointing out the 12Z shift in most (non-GFS) models towards an OTS solution:
 

KEY MESSAGE 3...Monitoring the potential for a coastal system
this weekend.

We continue to monitor the potential for snow associated with a
coastal low this weekend. Nearly all model solutions show a strong
coastal low forming, but there`s still considerable uncertainty
regarding both where that low will track, and what impacts we will
experience locally. Potential outcomes range anywhere from a storm
that tracks well out to sea with little impact locally, to a storm
that tracks closer to the coast and produces heavy snowfall across
the region.

The general flow pattern forecast by models has many of the synoptic
features associated with Mid-Atlantic snowstorms, with ridging along
the West Coast, troughing along the East Coast, ample cold air
in place at the surface, and then downstream blocking over the
North Atlantic. However, the trend with incoming EPS and GEPS
trended significantly downward with probabilities for snow,
ultimately showing a further southeast and out to sea track. The
12z GFS shows the potential snowier solution, and GEFS
probabilities for snow trended upward. Spatially speaking,
probabilities are highest for snow in all guidance the further
southeast you go. In our area, southern Maryland would have the
greatest chance at seeing snow.

It`s worth noting that the flow pattern at upper levels preceding
this storm is highly complex. The primary disturbance that will
ultimately contribute to the development of the system is actually
located over Newfoundland currently and will rotate westward around
an upper low centered over Hudson Bay, before turning southward and
digging out the trough that will eventually provide the forcing for
the development of the coastal low. As this disturbance turns
southward, it will also be influenced by an upper low over Alaska
and a building ridge over the West Coast. Given the high complexity
of these interactions, it may take another 1-2 days for models to
settle into a higher confidence solution, and as a result, the door
is still open for large forecast shifts.

[Franklin0529]

Discussion

The ongoing settling of cold surface high pressure and additional
surges in the wake of the historic winter storm will maintain
dangerously cold temperatures for the central and eastern U.S. well
into next week as per the Climate Prediction Center. The airmass
may be more prolonged in areas with widespread snow/ice coverage
and enhanced radiational cooling. Amplified mean troughing aloft
will meanwhile bring rounds of weak to moderate clipper system
snows from the north-central U.S. to the Great Lakes.

In this anomalously cold pattern, there is potential for wintry
precipitation into the Gulf Coast states late week as upper trough
translation leads into northern Gulf frontal wave genesis. Wave
progression downstream and trough/closed low development aloft is
now increasingly likely to set the environment to produce a
significant Eastern Seaboard Coastal Winter storm expected to
rapidly deepen while lifting over the western Atlantic off the
Southeast Saturday and Mid-Atlantic/New England Sunday. Uncertainty
has improved but remains with the exact track of the low which
impacts the onshore wintry precipitation focus and footprint.
However,
the growing consensus at this time is for heavy snow potential
from the eastern Carolinas/Mid-Atlantic through coastal southern
New England. The forecast strength of the deep low suggests high
winds/waves and coastal flooding would also be expected.

[BristowWx]

That AFD from Sterling was a mic drop.  They said wait and see and don’t get married to any model run until tomorrow.  Hard to argue that one. 

[Nomz]

I think life would be a lot more fun if all we got were surface maps

[GreyHat]

7 minutes ago, BristowWx said:

That AFD from Sterling was a mic drop.  They said wait and see and don’t get married to any model run until tomorrow.  Hard to argue that one. 

I suggested Thursday depending on sampling 

 

[snowmagnet]

9 minutes ago, BristowWx said:

That AFD from Sterling was a mic drop.  They said wait and see and don’t get married to any model run until tomorrow.  Hard to argue that one. 

Agreed! That is pretty positive at this point. 

[Terpeast]

may be hopium, but I remember bluewave posting a year or so ago a 3-run animation of the Euro that had a 2021 (or 2022? can't remember) storm 1000 miles OTS in one run, and then a NYC bullseye hit 2 runs later. 

[Shad]

ICON looking better to anyone at 78?

[wxmvpete]

21 minutes ago, BristowWx said:

That AFD from Sterling was a mic drop.  They said wait and see and don’t get married to any model run until tomorrow.  Hard to argue that one. 

Glad to see Sterling and I are on the same wavelength: https://www.wpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=qpfhsd

[Nomz]

2 minutes ago, Shad said:

ICON looking better to anyone at 78?

At h90, looks better than 12z. Also looks better than 12z euro and UK, but not as good as 12z GFS.

[Cobalt]

4 minutes ago, Shad said:

ICON looking better to anyone at 78?

NS lobe is definitely further West than 12z through 72, but doesn't look like it's gonna get its act together. 

[das]

1 hour ago, Bob Chill said:

CIPS analogs from the 12z gfs run are quite weenie'ish... lol

Goodness, that's like a Who's Who of greatest hits.

I like one of the mets comments in here from earlier this morning.  It's a powerful and delicate setup.  It'll be fun to see how this unfolds.