Central PA Winter 25/26 Discussion and Obs

[Mount Joy Snowman]

ICON holds steady.

[717WeatherLover]

My brain requires me to see data in an orderly matter so I took a second to do this to make it easier to judge as we go.  We can laugh as we pass each person's prediction!

User	Prediction
Wmsptwx	0.01
Bud Bundy	8.2
Blizz	12.3
canderson	12.8
717lover	13.1
nut	13.9
ITT	14.2
2001kx	14.5
MAG	15
MJS	15.5
paweather	16
pawatch	16.4
Subliminal87	16.87
Festus	17
Jns	17.5
Yardstick goes somewhere	19.3
Carlisle	19.59
SnowPlowGuy88	22

[Mount Joy Snowman]

FV3 still snowing heavily and has sleet line south of PA at 7pm.

[canderson]

40 minutes ago, Superstorm said:

NAM is definitely getting to where we want to see it.


.

I had a long heart-to-heart conversation with it at bedtime. 

[WmsptWx]

WARNED

 

URGENT - WINTER WEATHER MESSAGE

National Weather Service State College PA

1020 AM EST Fri Jan 23 2026

 

...MAJOR WINTER STORM THIS WEEKEND...

 

PAZ004>006-010>012-017>019-024>028-037-041-042-045-046-049>053-058-

240915-

/O.UPG.KCTP.WS.A.0002.260125T0300Z-260126T1800Z/

/O.NEW.KCTP.WS.W.0001.260125T0300Z-260126T1800Z/

Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-

Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin-

Juniata-Tioga-Northern Lycoming-Sullivan-Southern Clinton-

Southern Lycoming-Union-Snyder-Montour-Northumberland-Columbia-

Schuylkill-

Including the cities of Bloomsburg, Coudersport, Lewistown,

Warren, Lewisburg, Philipsburg, Mount Union, Altoona, Lock Haven,

Johnstown, Wellsboro, St. Marys, Clearfield, State College,

Huntingdon, Laporte, Mansfield, Emporium, Sunbury, Berwick, Trout

Run, Pottsville, Danville, Williamsport, DuBois, Mifflintown,

Selinsgrove, Shamokin, Renovo, Bradford, and Ridgway

1020 AM EST Fri Jan 23 2026

 

...WINTER STORM WARNING IN EFFECT FROM 10 PM SATURDAY TO 1 PM EST

MONDAY...

 

* WHAT...Heavy snow expected. Total snow accumulations between 10

  and 18 inches.

 

* WHERE...A portion of central Pennsylvania.

 

* WHEN...From 10 PM Saturday to 1 PM EST Monday.

 

* IMPACTS...Travel will be very difficult to impossible. Widespread

  and prolonged travel disruptions are expected.

 

* ADDITIONAL DETAILS...Snow will overspread the area late Saturday

  night, becoming heavy at times through Sunday with accumulation

  rates of one to two inches per hour at times. Frigid temperatures

  and wind chills are expected before, during, and after the winter

  storm. Some blowing and drifting snow is possible.

 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

 

Persons should consider delaying all travel. Motorists should use

extreme caution if travel is absolutely necessary.

 

&&

 

$$

[Jns2183]

My biggest concern is the alignment of when we have truly thick dendritic growth zone to when we have the best omega

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[canderson]

CTP has added a sleet mention to my grid 

 

Saturday Night

Snow, mainly after 1am. The snow could be heavy at times. Low around 12. Calm wind becoming east around 5 mph after midnight. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible. 

Sunday

Snow before 1pm, then snow, possibly mixed with sleet. The snow could be heavy at times. High near 20. East wind around 7 mph. Chance of precipitation is 100%. New snow and sleet accumulation of 7 to 11 inches possible. 

Sunday Night

Snow. Low around 17. Chance of precipitation is 90%. New snow accumulation of 3 to 5 inches possible. 

 

 

[canderson]

Also it’s windy again. 35 mph winds. 

[Jns2183]

Great summary

Im definitely leaning towards a 50/50 blend right now

When we're staring at model snowfall maps for the next storm, you'll often see options like the plain old 10:1 ratio (10 inches of snow per 1 inch of liquid) or the Kuchera method, which a lot of sites use because it's supposed to be smarter. The Kuchera approach looks at the warmest temperature anywhere in the atmospheric column (usually up to about 18,000 feet) and plugs it into a formula to tweak the ratio. If that max temp is really cold (say below about -2°C or 28°F), it can spit out fluffy ratios well above 10:1—sometimes 20:1 or more—while warmer columns drop it down toward 5:1 or even lower to account for denser, wetter snow or partial melting. It's a quick way to adjust totals without needing super detailed soundings, and it often gives higher accumulations than straight 10:1 in cold-air setups.But here's the catch that a lot of amateurs (and even some pros) overlook: Kuchera basically ignores the dendritic growth zone (DGZ), that magic layer between roughly -12°C and -18°C where those big, starry, branching snowflakes form best. Those dendrites trap tons of air and stack up super fluffy (high ratios like 15:1–30:1+), especially when the whole layer stays saturated and deep. Kuchera just keys off the single warmest temp in the column, so it can seriously underestimate snowfall in setups with a nice, cold, deep DGZ even if the column max isn't ultra-frigid, or overestimate in marginal/warm cases. Next time you're comparing maps, check model soundings for how beefy that -12° to -18°C layer looks



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[Jns2183]

We aren't getting steep lapse rates within the dgz (thunder snow!) that can easily overcome a small dgz, this storm. Our rates are maxed when we get a huge dgz with good accent and lapse rates above it. Compare image used to show this (1st) with that one from the GFS when rates are great.

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[Superstorm]

GFS is not backing down


.

[AccuChris]

12z GFS rock steady


.

[canderson]

GFS is a bulldog with this storm 

[WmsptWx]

Three days ago we were dismissing the GFS and now we are hoping it verifies. What a turnaround.

[GrandmasterB]

Canadian is a tick colder.  Almost GFS like in its progression.  Would love to see the Euro do the same here.

[Superstorm]

That next storm continues to show up on GFS.


.

[anotherman]

Oh my goodness.  The GFS....we appear to be entering a special period.

[Superstorm]

Would rival Superstorm 93 totals in the South.


.

[canderson]

For personal travel reasons, I am rooting against next weekend’s blizzard lol 

[Mount Joy Snowman]

I don't believe the RRFS was posted.  Keeps the sleet line right along the southern Lancaster tier during the height of the storm but never quite infiltrates, would be perfect verbatim.  

[GrandmasterB]

Posted by mitchnick in the MA and I completely agree, "With the euro to go (and obviously that could change things quite a bit) this run (12Z) has been the first time I saw legit improvement across the guidance and not just grasping at noise level changes.  Until now I felt each run was a very slow bleed in the wrong direction but 12z was an actual improvement across everything so far imo."

[Yardstickgozinya]

@Mount Joy Snowman.Maybe you didn't realize the proximity fused thing was my light, harted way of me asking you a question. What's your plans with my elevation or were you just more or less just curious ? 

[sauss06]

28 minutes ago, canderson said:

For personal travel reasons, I am rooting against next weekend’s blizzard lol 

me too bro. Taking my 2 favorite chicks (both Hockey nuts) to Happy Valley Friday night for Hockey game. 

[Mount Joy Snowman]

15 minutes ago, Yardstickgozinya said:

@Mount Joy Snowman.Maybe you didn't realize the proximity fused thing was my light, harted way of me asking you a question. What's your plans with my elevation or were you just more or less just curious ? 

Haha no worries. I’ve just been running kids around all morning while trying to look at models and post during breaks. Just forgot to respond. No reason, I just love elevation and figured you had a bit on your side out that way, as I know it climbs pretty decent over there behind CXY. Makes a difference around here.  I’m one of those guys who can just stare at topographic maps and be completely entertained for hours ha. 

[Jns2183]

Posted by mitchnick in the MA and I completely agree, "With the euro to go (and obviously that could change things quite a bit) this run (12Z) has been the first time I saw legit improvement across the guidance and not just grasping at noise level changes.  Until now I felt each run was a very slow bleed in the wrong direction but 12z was an actual improvement across everything so far imo."

Look at the satellite water vapor images in western Canada. That high is hauling ass down and that might be why

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[Yardstickgozinya]

Just now, Mount Joy Snowman said:

Haha no worries. I’ve just been running kids around all morning while trying to look at models and post during breaks. Just forgot to respond. No reason, I just love elevation and figured you had a bit on your side put that way, as I know it climbed pretty decent over there behind CXY. I’m one of those guys who can just stare at topographic maps and be completely entertained for hours ha. 

 My best buddy in lLisburn  is a a topo junkie too.   Check out Topo ranger on youtube.  He's just a geo weenie that goes around to different local sites of geographic importance. I enjoy his videos, especially on the lower Susquehanna. 

[Yardstickgozinya]

7 minutes ago, Jns2183 said:

Look at the satellite water vapor images in western Canada. That high is hauling ass down and that might be why

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I posted a picture this morning of the air mass descending. It looked quite impressive

[Mount Joy Snowman]

Euro pushes sleet line well up into York/Lanc by 7pm but only after most the precip has fallen.  10:1 below....

[Ruin]

Sigh still bydont buy this warm pusg of air

[Yardstickgozinya]

8 minutes ago, Ruin said:

Sigh still bydont buy this warm pusg of air

It's several hours old now but I have a video that i'm going to post for you . Guy does a good job of sharing how it could happen.