Central PA Winter 25/26 Discussion and Obs

[MickeyTim6533]

Glad to have joined this site, excited about this storm and all the insight on here from everyone!

[canderson]

Feels like really nice 6-10” as a baseline storm for Harrisburg to me. 

[Subliminal87]

I work a 24 hour shift Saturday in west Chester area and then have to drive home Sunday morning at 6am to carlise.  
 

luuuuuuucky me.  

[AccuChris]

18z Euro AI holds firm and the 18z GEFS AI was actually a tick better in QPF too



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[AccuChris]

Here are also the latest new para (experimental NBM) snow outputs and regular NBM. Remember these are simply 10:1 maps so the true snowfall via proper ratios are not considered here



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[AccuChris]

And finally for good measure, the 18z Euro Op
Kuchera snow


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[canderson]

The weenie suicide rate in the MA thread makes Wall Street in 1929 blush.

[Jns2183]

Here's from an infograph I made from the text bulletins of the 19z NBM. specifically regarding snowfall percentile amounts by region

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[canderson]

3 minutes ago, Jns2183 said:

Here's from an infograph I made from the text bulletins of the 19z NBM. specifically regarding snowfall percentile amounts by region

Sent from my SM-S731U using Tapatalk
 

The NWS could use your help

[MAG5035]

2.5” so far this evening here, what a nice surprise. Was down at our camp in NW Huntingdon Co earlier and about the same there as well. Roads are a mess.

[Caveman]

8 minutes ago, Jns2183 said:

Here's from an infograph I made from the text bulletins of the 19z NBM. specifically regarding snowfall percentile amounts by region

Sent from my SM-S731U using Tapatalk
 

That’s very cool!  The communication of the numerical guidance in one succinct graphic!  Awesome!

[pasnownut]

1 hour ago, paweather said:

A foot of snow? 

my point was that it's NOT going to cut.  Strung out and less amped means not cutting west of us.

[Blizzard of 93]

1 hour ago, MickeyTim6533 said:

Glad to have joined this site, excited about this storm and all the insight on here from everyone!

Welcome aboard!

[paweather]

8 minutes ago, pasnownut said:

my point was that it's NOT going to cut.  Strung out and less amped means not cutting west of us.

Gotcha! 

[Blizzard of 93]

53 minutes ago, AccuChris said:

Here are also the latest new para (experimental NBM) snow outputs and regular NBM. Remember these are simply 10:1 maps so the true snowfall via proper ratios are not considered here



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I think the NBM factors in ratios.

[Blizzard of 93]

Here is the close up view of the 18z Euro  for our region.

[paweather]

1 minute ago, Blizzard of 93 said:

Here is the close up view of the 18z Euro  for our region.

Let it snow!

[SnowPlowGuy88]

Getting excited for my first long duration plow event since ‘21. I have since switched companies and now only have to take care of our shop/storage unit site. Not a lot of places to put the snow, going to have to account for that since we should still have some chances down the road. Won’t be far from @Yardstickgozinya and will try to get some pics in. We have a full kitchen in the shop, thinking about whipping up some potato soup and throwing it in a croc pot for some quick refreshment. 

[Jns2183]

For anyone who wants a look at Google's new weather model, meteorologist Eric Fisher has a simple forcast viewer on his github

https://efisher828.github.io/weathernext/


Here's more information on it
https://deepmind.google/science/weathernext/

https://developers.google.com/earth-engine/datasets/catalog/projects_gcp-public-data-weathernext_assets_weathernext_2_0_0

If anyone has the technical background I believe you can already do a whole lot more

Finally this new endeavor I came across that has a whole lot of potential even though it currently only had temperature and wind verification scores.
https://www.actuallyweather.com/?run_date=2026-01-21

What's neat is it has it by major weather reporting station, like kmdt. The promise is soon we could have scorecards for about 50 variables like snow, and rainfall, along with ability to customize periods. And yes, I understand the scorecards put out by the nws and euro are for much larger areas and maybe even tracking slightly different metrics, but dear God they require hours of study to even interpret probably as the user base for them usually have phD. While I understand that accuracy in temperature or qpf for a single location has the probability of noise being potentially exponentially bigger than the signal, (i.e a model, especially an mL one that continuelly maximizes minute station details may quickly Decoherence at the upper air forcasts that drive accurate forcasting at a greater geospatial scale; in happy that a true effort is finally being made to score at the level we all care bout and spend so much effort discussing.

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[Jns2183]

Here's substack post from new app
https://open.substack.com/pub/actuallyweather/p/which-forecast-is-best?utm_source=share&utm_medium=android&r=16mod

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[MAG5035]

8 minutes ago, Blizzard of 93 said:

I think the NBM factors in ratios.

It does, I know reading into the updates of the new version that it mainly applies the Cobb method for snow ratios. I think the current version does to a degree as well, not sure. But the NBM snow maps do factor in variable ratios. 

[Caveman]

17 minutes ago, Jns2183 said:

Here's substack post from new app
https://open.substack.com/pub/actuallyweather/p/which-forecast-is-best?utm_source=share&utm_medium=android&r=16mod

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Interesting...even from a slide rule old fart!

[Jns2183]

It does, I know reading into the updates of the new version that it mainly applies the Cobb method for snow ratios. I think the current version does to a degree as well, not sure. But the NBM snow maps do factor in variable ratios. 

These images may be of help

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[Yardstickgozinya]

21 minutes ago, SnowPlowGuy88 said:

Getting excited for my first long duration plow event since ‘21. I have since switched companies and now only have to take care of our shop/storage unit site. Not a lot of places to put the snow, going to have to account for that since we should still have some chances down the road. Won’t be far from @Yardstickgozinya and will try to get some pics in. We have a full kitchen in the shop, thinking about whipping up some potato soup and throwing it in a croc pot for some quick refreshment. 

Rite on brother, sounds like you got the right idea. I went down to the the fairview township yard waste facility  and made old Larry dig me out some wood today and cut down a black locust, i've been saving for a extra cold. occasion. I'm thinking  Mississippi pot roast along with some  Chicken and rice soup on the rocket stove Saturday before I make my hike from Lisburn back home to New Cumberland in ten degree powder. There will only be one idiot out there in a blaze orange snowsuit. Three honks, if you're loving the weather. 

[Blizzard of 93]

18z EPS gives us lots of wiggle room in southern PA for slight adjustments in just about every direction.

Ensemble maps are only available in the 10-1 ratios.

[Jns2183]

The 19z NBM probabilistic snowfall guidance for the Saturday night through Monday morning window shows a really sharp divide across the region. It's not just "big snow might happen"—the risk profiles vary a ton depending on where you are.

For spots like Lancaster (KW05), Pottsville (KZER), and York/Gettysburg (KTHV), the floor is nasty: their 10th percentile sits around 10–12 inches. That means even if things underperform noticeably, you're still looking at enough snow to break out the shovel and measure in proper accumulations. That's typical when the cold air is locked in and the big question marks are how long the heavy precipitation band sticks around and exactly where the deformation zone or mesoscale banding sets up.

Over toward Harrisburg/Carlisle (KCXY) and the Reading/Philly corridor (KRDG), it's the classic high-end skew: medians in the 14–16" range, but the 90th percentile climbs to 32–35" or so—more than double the median in some cases. That's straight out of the playbook for those arctic, high snow-to-liquid ratio setups. The outcome rides almost entirely on mesoscale features: where the strongest frontogenesis band parks, how long it persists, and whether lift really peaks in the dendritic growth zone. A tiny shift in that band can turn a solid warning-level event into something historic at one spot while the next town over stays more moderate—all from the same synoptic storm.

Up north at places like KZER and KWBW, the spreads look tighter and more stable. That tracks with a solidly entrenched cold dome: minimal risk of mixing or sleet eating into accumulations, fewer p-type headaches, and totals mostly hinging on how long the precip keeps firing rather than ratio roulette. So the southern and valley areas are wrestling with the full uncertainty beast (track wobbles, banding details, ratios), while the ridges and northern zones basically boil down to one main question: how long?

The 07z to 13z to 19z NBM runs on January 21 show the storm strengthening and coming into clearer focus rather than falling apart. QPF keeps climbing steadily across the board with each cycle, while snowfall amounts spike sharply from 07z to 13z and then basically level off near their highest values by 19z. That's a classic sign of the models gaining confidence: the debate shifts from "does this even happen" to "where does the heaviest axis land and how efficient will the snow be."

The 13z run had the fluffiest ratios—some spots like State College and Wilkes-Barre pushing 20:1 or better—but 19z pulls them back to a more realistic 15–19:1 range. Totals hold strong, though, because the extra moisture more than makes up for the slightly lower ratios. No major backtracking shows up late in the day either; places like Lancaster and Harrisburg stay nearly flat from 13z to 19z, which is reassuring as we get closer. The northern edge (KWBW) sees the biggest jump, with totals climbing from 7.8" to around 14" and holding there, suggesting the heavy band is expanding farther north. Overall, the cold air looks solid, moisture is trending higher, and the guidance is locking in on a legit high-impact snow instead of still questioning if it'll show up.

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[SnowPlowGuy88]

5 minutes ago, Yardstickgozinya said:

Rite on brother, sounds like you got the right idea. I went down to the the fairview township yard waste facility  and made old Larry dig me out some wood today and cut down a black locust, i've been saving for a extra cold. occasion. I'm thinking  Mississippi pot roast along with some  Chicken and rice soup on the rocket stove Saturday before I make my hike from Lisburn back home to New Cumberland in ten degree powder. There will only be one idiot out there in a blaze orange snowsuit. Three honks, if you're loving the weather. 

Lmao I Love it. Maybe when I am refueling at that rutters we can exchange meals lol 

[Yardstickgozinya]

Anybody who drives around fairerview township knows me and my dog Echo. Just wondering if you're one of those people. LOL

[pasnownut]

found this read interesting from CTP afternoon disco

KEY MESSAGE 2: Increasing odds for heavy snow and moderate to
major winter storm impacts Saturday night through Sunday

Confidence continues to increase in the potential for heavy
snow and moderate to major winter storm impacts across central
PA this weekend. As is often the case, the primary model
uncertainty differences center around the interaction between
the northern and southern branches of the jet stream which will
ultimately steer the storm track and associated placement of
winter wx/max snowfall. Latest models have doubled-down on the
northward trend that was very evident in the previous 21/00Z
model cycle. Big ? remains will that trend hold or will there be
a reversion back to the south.

What we know at this juncture:
1. Ptype should be all snow as arctic air remains locked in
place

2. Most likely timing for heavy snow is Saturday night
through Sunday night

3. Odds of >6" and >12" of snow have trended higher (maximized
over south central/southeast PA) with an increasing risk for
moderate to major winter storm impacts this weekend

What we don`t know yet:
1. Exactly when, where and how much snow will fall

[Yardstickgozinya]

7 minutes ago, SnowPlowGuy88 said:

Lmao I Love it. Maybe when I am refueling at that rutters we can exchange meals lol 

Anytime brother.  I'm also the recognizable Green beat classic 97 s10 always at rutters.