January 24-25: Miracle or Mirage

[Ephesians2]

2 minutes ago, Terpeast said:

I don’t want too much to change either. But if I had to guess, final track will be shifted about 100 miles north of what the entire model average is now. Maybe 150. Might put our forum in the jack, and maybe even flirt with mixing across the southern half.

I’ve seen so many big ones shift north like this. 

Are you thinking ice storm potential in Southwest/Central/Southside VA into RIC? Or mostly sleet?

[Amped]

8 minutes ago, bncho said:

The Weather Channel has named this storm. 

It's called Winter Storm Fern.

I'm calling it 'The Baja Bastard'. I dont care what TWC thinks.

[stormtracker]

NAM looks like more interaction vs 18z  going  back there in the west?

[Buddy1987]

4 hours ago, CAPE said:

Bob chill!

@Bob Chill I swear to god man ever since you moved down to this neck of the woods, crazy outstanding weather has been transpiring in winter months. It’s time to move your Aunt, Uncle, Niece and 7th cousin if need be down here and finish off the luck of all luck. Even if half of that came to fruition my lord would I be beyond myself. 

[wxdude64]

6 minutes ago, CAPE said:

Time to check the latest Natty Blend.. holy fuck..just keeps getting better

When was the last time The Natty showed the ENTIRE state of VA at 12"+??

[weathercoins]

10 minutes ago, mitchnick said:

They wanted 2015, they got it! But forgot the price...winters in the Mid Atlantic.  Lol

I lived up there 2014-2017, got very lucky, *and* flew down to Baltimore for January 2016.  I knew it was a snow drought recently, did not realize it was a *no six inch snow for four years* drought 

[Terpeast]

2 minutes ago, SnowenOutThere said:

No, no lets not reshuffle like that. Genuine question is where do you see the north shift coming from? Synoptically I have a hard time seeing how much further it can go north with a solution like the 18z Euro as it has a perfect phase.

If the cold air/high and TPV strength was overdone by the models AND the NS vort digs even more, that would do it. But I do think 100 miles is the max it can shift from this setup and lead time. Could be less. Hopefully not more. 

[clskinsfan]

NAM is the NAM. But it already opens the southern wave at 51 and has much less confluence in the east. It would be more north than the GFS imo. Not even gonna look beyond that. No point. 

[bncho]

2 minutes ago, Terpeast said:

If the cold air/high and TPV strength was overdone by the models AND the NS vort digs even more, that would do it. But I do think 100 miles is the max it can shift from this setup and lead time. Could be less. Hopefully not more. 

With this added 100 mile north shift would this system trend more juicy/amped?

[CAPE]

1 minute ago, clskinsfan said:

NAM is the NAM. But it already opens the southern wave at 51 and has much less confluence in the east. It would be more north than the GFS imo. Not even gonna look beyond that. No point. 

Its an awful model. Look at it out of boredom, or for entertainment purposes. The real models will be along soon.

[bncho]

1 minute ago, CAPE said:

Its an awful model. Look at it out of boredom, or for entertainment purposes. The real models will be along soon.

Would you say the NAM 3km is a good model inside its useful range of 36 hours?

[Ralph Wiggum]

15 minutes ago, bncho said:

The Weather Channel has named this storm. 

It's called Winter Storm Fern.

Wtf is Fern? Fern as in  Fernando? Why not Ferb? 

[jayyy]

Patiently waiting for our CMC smack down

[wasnow215]

18 minutes ago, Maestrobjwa said:

Bruh that thing can't even get 48 seconds right!

Exactly-as dependable as CJ Stroud

[Jebman]

4 hours ago, CAPE said:

Bob chill!

Bob Chill you are gonna need a bigger tractor.

[Quasievil]

4 minutes ago, clskinsfan said:

NAM is the NAM. But it already opens the southern wave at 51 and has much less confluence in the east. It would be more north than the GFS imo. Not even gonna look beyond that. No point. 

It’s not an official storm until we’re NAM’d. That’s the benchmark. 

[jayyy]

Would you say the NAM 3km is a good model inside its useful range of 36 hours?

So good it’s being retired

[SnowenOutThere]

Just now, Terpeast said:

If the cold air/high and TPV strength was overdone by the models AND the NS vort digs even more, that would do it. But I do think 100 miles is the max it can shift from this setup and lead time. Could be less. Hopefully not more. 

I guess, though that supposes that this phase goes off cleanly which I doubt at this time period. 

[CAPE]

1 minute ago, bncho said:

Would you say the NAM 3km is a good model inside its useful range of 36 hours?

yes

[Twilly05]

2 hours ago, stormtracker said:

I was late.  Was ordering dinner, lost track of time.  I sometime forget how early and fast the Euro gets done at 18z.  And I got in a trance with that one panel...couldn't believe that H5 map man.

ALl in all, I thinking my 6 to 10 is sitting good...maybe 12 now?

Might double that

[CAPE]

Just now, jayyy said:

So good it’s being retired

Still useful. 12km not so much.

[NorthArlington101]

LWX AFD is eye candy. Worth a read. Not really worried about mixing, >10:1 ratios…

[Warm Nose]

2 minutes ago, Ralph Wiggum said:

Wtf is Fern? Fern as in  Fernando? Why not Ferb? 

[stormtracker]

6 minutes ago, CAPE said:

Its an awful model. Look at it out of boredom, or for entertainment purposes. The real models will be along soon.

THIS

[stormtracker]

Yeah, NAM is def more interaction and further east vs 18z by a good bit

[Warm Nose]

859
FXUS61 KLWX 210229
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
929 PM EST Tue Jan 20 2026

.WHAT HAS CHANGED...
Increasing confidence for a significant/impactful winter storm
with several inches of snow late Saturday into Sunday.
Additionally, increased snow totals over portions of the
Alleghenies late Wednesday afternoon into Thursday morning as a
series of fronts pass through.

&&

.KEY MESSAGES...
- 1) Increasing confidence of a significant winter storm across
the region on Saturday into Sunday.

- 2) Frigid temperatures are looking likely this weekend into
  early next week.

- 3) Accumulating snow over portions of the Alleghenies late
  Wednesday afternoon through Thursday morning.

&&

.DISCUSSION...
KEY MESSAGE 1...Increasing confidence of a significant winter storm
across the region on Saturday into Sunday.

Ingredients are slowly coming together to produce a potentially
significant winter storm across the region this weekend. Based on
the latest guidance, wintry precipitation arrives by Saturday
evening and continues throughout Sunday, while possibly continuing
into Sunday night. While deterministic guidance continue to show the
run-to-run variability expected in such solutions, the overall trend
has been bringing the higher amounts toward central Virginia. In a
multi-day sense, global ensemble probabilities are very high in
seeing 6 inches or greater, particularly south of I-70. This comes
with the presumed snow-to-liquid ratio of 10:1 which this system
will not be given the Arctic nature of the air mass. Ratios will be
considerably higher yielding a fluffier snow. With the parent
features still across the more barren high latitudes, models may
take another day or two to resolve such features with better
precision.

On the synoptic pattern side of things, many ingredients are in
place to produce the mentioned winter storm. On Saturday, Arctic
high pressure (1045-1050 mb) across the Midwest eventually reaches
New England by the evening as a still robust 1040 mb anticyclone.
This yields the familiar cold air damming wedge setup which
stretches down into the southeastern U.S.

Looking aloft, a split jet structure is evident with deep cyclonic
flow in the northern stream and a progressive feature ejecting out
of the Four Corners. The downstream confluent flow will aid in ample
forcing across vast portions of the central/eastern U.S. While the
main surface low sweeps across the Gulf Coast states, a broad area
of isentropically driven precipitation spreads over the frigid air
mass to the north. Precipitation type issues appear minimal through
the event, although far southern Maryland could see some changeover
to freezing rain or sleet at some point on Sunday. An energy
transfer eventually unfolds Sunday afternoon/evening which focuses
to deepening low pressure off the Outer Banks coast. Eventually this
features pulls away from the coast late Sunday which gradually
brings the brunt of the snow fall to an end.

With the system not arriving until Saturday evening sometime, now is
the time to prepare for this winter storm. Check back at the office
website (weather.gov/lwx) as well as the winter page as the system
moves into the Day 1-3 period (weather.gov/lwx/winter).


KEY MESSAGE 2...Frigid temperatures are looking likely this weekend
into early next week.

As mentioned in the winter storm section, Arctic high pressure takes
charge over the weekend which yields frigid temperatures across the
area. On Saturday, forecast 850-mb temperatures range from -15 to -
20C which even dry adiabatic mixing would keep surface temperatures
below freezing. However, given the time of year and the fact 1000-
850 mb winds are northerly, mixing largely tops out around 900-mb.
With that said, Saturday`s high temperatures should struggle to
escape the teens in most spots, with a few low 20s possible across
far southern Maryland. Along the Allegheny Front, single digits are
likely all that can be mustered. As snow comes in Saturday night,
this will fall amidst temperatures in the single digits to lower
teens.

While a small increase in temperatures is expected on Sunday, it
will likely not be noticeable with area-wide highs in the mid-teens
to low/mid 20s. As snowfall comes to an end on Sunday night, the
forecast calls for overnight lows in the single digits to lower
teens. Looking ahead into the next work week, frigid conditions
should persist. Depending on the degree of snowpack, the forecast
may even be too optimistic in terms of "warmth". While daily highs
next week are to push into the 20s, all could see low temperatures
in the low/mid single digits on certain nights. Given elevated winds
overnight, some locations along the Allegheny Front could see wind
chills fall into the negative teens.

- 3) Accumulating snow over portions of the Alleghenies late
  Wednesday afternoon through Thursday morning.

A warm front will lift into the area Wednesday into Thursday with a
cold front to follow Thursday night. This series of fronts will
deliver a period of accumulating upslope snow shower/squalls across
the Alleghenies late Wednesday afternoon into early Thursday
morning. Elsewhere, dry conditions are expected with moderating
temperatures and breezy conditions. Highs Wednesday will push
back into the mid 30s and low 40s after starting in the upper
single digits and low to mid teens. Temperatures warm even more
Thursday with widespread highs in the mid 40s and low 50s east
of the Alleghenies under increased south/southwest flow.

As for snow in the Alleghenies, totals have come up slightly even
with marginal temperatures profiles. 18z/00z hi-res CAM guidance
suggest a dusting -3" of snow along the western facing slopes of
the Alleghenies between 18z/1pm Wednesday through 12z/7am
Thursday. Precip should mix with rain below 2500 feet at the
onset with all snow expected during the overnight period
Wednesday into Thursday morning. Snow to liquid ratios look to
remain at 9:1/10:1 increasing to 13:1 during the peak of the
event. The bulk of the snow looks to fall during the warm
frontal passage with upslope snow showers & perhaps a few
squalls lingering into Thursday morning as a weak cold front
swings through. Some instability has also been noted in the DGZ
leading to the potential for near advisory level snow in far
western portions of Garrett Co. (west of the Eastern Continental
Divide) and down into portions of western Grant Co. These
locations could see 2-4" of snow with localized amounts up to 5"
along western favored slopes above 2800 feet (i.e Keysers
Ridge, Piney Mountain, Hoyes Crest/Backbone Mountain).
Confidence is medium for an advisory at this time and will
likeLy be further evaluated on the overnight shift. Expect slick
travel and delays along I-68/US-40 west of Frostburg, MD and
US-219 from the MD/PA line to WV line late Wednesday evening
through Thursday morning. Further east downsloping will eat away
at any precipitation chances outside of a rogue snow shower
pushing toward the Catoctins/northeast MD as the front lifts
through Wednesday evening. No accumulation is expected at this
time as plenty of dry air will be hard to overcome east of the
mountains. With the series of fronts pushing through expect wind
gusts around 25-35 mph with gusts up to 40 mph along the
ridges. Winds will gradually decrease Thursday night into
Friday.

Next chance of wintry precipitation arrives Friday, especially
in locations south of I-66/US-50. This is due largely in part to
strong isentropic lift/warm air advection ahead of the southern
stream upper level low. This could lead to overrunning
precipitation in the form of light snow or even a light wintry
mix (rain/snow/sleet) across the central VA Piedmont and
northern neck. Confidence in this remains low at this time,
given recent model trends. Even with that said, something to
watch given the dynamical setup in place before the main event
this weekend. Highs Friday range from the teens over the
mountains to mid 30s and low 40s east.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions will continue through Friday morning as surface high
pressure shifts offshore and a series of moisture starved fronts
push through. The biggest concern for aviators will be the wind,
especially heading into the midweek period. Expect southerly winds
Wednesday gusts 20 to 30 kts outside the mountains as a warm front
lifts through. These winds will slacken a bit Wednesday night before
increasing again Thursday ahead of an approaching Arctic cold
frontal boundary. Expect 15 to 25 kt gusts Thursday out of the west
and southwest. LLWS also cannot be ruled out Wednesday into
Wednesday night although confidence was too low to include in the
corridor at this time. Winds will turn back to the northwest
Thursday night into Friday with gusts less than 15 kts expected.

A light rain/snow mix could impact terminals across central and
southern VA Friday although confidence is low at this
time.Skies begin overcast on Saturday morning, but any snow
should not commence until around Saturday evening. As ceilings
lower through the day, expect restrictions to kick in ahead of
this swath of snowfall. At that point, expect a lengthy period
of IFR caliber conditions Saturday evening/night and into all of
Sunday. Given the degree of cold air in place, this should be
an all snow event across the terminals. KCHO could get close to
the line where freezing rain and sleet mix in on Sunday, but it
remains rather uncertain.

Initial winds will be out of the northwest on Saturday morning
before shifting to the north to northeast through the day as Arctic
high pressure builds across New England. For Sunday, winds largely
remain northerly as low pressure eventually develops off the North
Carolina coast later in the day. Gusts each day over the weekend
should top out around 10 to 15 knots.

&&

.MARINE...
Sub-SCA level winds are expected through Wednesday morning with SCA
conditions returning Wednesday afternoon and night under southerly
channeling. Gusts of 20 to 25 kts are expected at this time. Highest
gusts look to be over the open waters of the bay/tidal Potomac.
Winds will fall back below SCA levels for most of the waters
Thursday into Thursday night under westerly flow. This will
continue into Thursday night into Friday. Additional SCAs will
be needed Friday night.

With Arctic high pressure pushing from the Midwest toward New
England on Saturday, northerly winds will increase across the
waters. Channeling effects look possible which may require Small
Craft Advisories, especially across the wider waters on Saturday
morning.

After a brief lull as winds shift to northeasterly, gradients
increase again on Saturday evening/night yielding additional 20 to
25 knot gust potential. These blustery winds continue into Sunday as
winds turn northerly. Widespread snow impacts the waters Saturday
evening through most of Sunday. There may even be a threat for some
freezing spray given the frigid nature of the air mass and elevated
wind fields.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

[Eskimo Joe]

9 minutes ago, bncho said:

With this added 100 mile north shift would this system trend more juicy/amped?

Not necessarily 

[Ralph Wiggum]

Just now, stormtracker said:

Yeah, NAM is def more interaction and further east vs 18z by a good bit

Pumping heights out ahead vs 18z. Good sign if anyone still fears suppression 

[Quasievil]

Well, seems as though LWX is all in. 

[Ralph Wiggum]

Dang that run was going to be something else.  Im ready for the real 0z stuff.