Central PA Winter 25/26 Discussion and Obs

[Jns2183]

The Regime Transition Probability Map is a visualization of a Markov Chain transition matrix, designed to quantify the likelihood of shifts between specific atmospheric states. It represents a century of regional snowfall data processed through a K-Means clustering algorithm.
Statistical Mechanics of the Map
* Axes: The vertical axis (Current Cluster) defines the point of origin, representing the weather regime of the most recent event. The horizontal axis (Next Cluster) represents the predicted destination for the subsequent atmospheric event.
* Probability Density: The numerical values and corresponding blue shading represent the probability (0.0 to 1.0) of a transition occurring between any two clusters. A value closer to 1.0 (darker blue) indicates a high statistical probability, while a value closer to 0.0 (lighter blue) suggests a rare or unlikely transition.
Current Regime Analysis: Transition from Cluster 3
Following the high-intensity coastal event on February 23, the atmospheric state is currently positioned in Cluster 3 (Extreme Synoptic). Analyzing the Row 3 data provides the following probabilistic insights:
* Pattern Persistence (3 to 3): The probability located at the intersection of Row 3 and Column 3 quantifies the likelihood of the atmosphere remaining in a high-intensity coastal redevelopment cycle.
* Regime Decay (3 to 2): Historically, late-February Cluster 3 events exhibit a strong statistical trend toward Cluster 2 (Clipper / Fast-Moving). This represents a transition from high-payload moisture systems to lower-accumulation, high-ratio arctic systems.
* Inland Transition (3 to 1): The probability of shifting to Cluster 1 (Miller B / Overrunning) indicates the likelihood of the next system following an inland track rather than the coastal track observed yesterday.
Probabilistic Representation
The map demonstrates that weather patterns are not random but operate within a set of statistically favored transitions. For a Cluster 3 point of origin, the high concentration of probability in the Cluster 2 column suggests a regime shift toward diminished regional totals. This indicates that while extreme events like the one yesterday are significant, they are statistically followed by a period of lower intensity as the seasonal atmospheric steering flow begins its spring transition.


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[Jns2183]

I'm not saying you don't speak the truth, but I have an unscientific hunch we're in for an anomalous spring. 

The historical Max and anomaly is March 1960. Maybe the month I dream about experiencing the most.

In March 1960, the Northeast saw a relentless pattern that produced 7 distinct measurable snow events for the Harrisburg (MDT) area, totaling that record-setting cumulative amount.
It wasn't just one "Superstorm"; it was a "parade" of systems that kept the ground white for nearly the entire month. Here is how that active March unfolded for Harrisburg:
March 1960 Storm Timeline (Harrisburg/MDT)
| Date | Snowfall Amount | Notes |
|---|---|---|
| March 3 | 10.5" | The primary "anchor" storm of the month. |
| March 10 | 1.8" | A cold-sector clipper system. |
| March 16 | 3.2" | Moderate overrunning event. |
| March 17 | 3.0" | St. Patrick's Day system. |
| March 22 | 2.0" | Late-season coastal influence. |
| Minor Events | 2.1" | Combined totals from minor dustings (March 4, 7, 8, 21, 24). |
| Total | 22.6" | (Catalog sum for distinct events) |


Prior to this month that winter had produced 27" of snow, similar to us now. But March was notice to all the new decade was a different beast

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[Blizzard of 93]

55 minutes ago, Jns2183 said:

The median snow for Harrisburg after a February storm like the one the other day this late in February here is the past outcomes

25th 0.48
Median 2.66"
75th 6.28"

So likely all we get rest of season is a 1"-3"/3"-6"

She's just about done.

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I think we have a long way to go until true Spring arrives this season. We have a few potential Winter events to track through next week. Then, we likely warm up for a week to 10 days. After that, the Teleconnections & MJO forecast indicate that mid March through at least early April could be a return to a colder pattern with the trough in the east.

I think we are tracking Winter storm chances through Easter week in early April this year. It fits the same pattern that we have had since around Thanksgiving. Any warm ups have been brief & i think that continues.

[Blizzard of 93]

13 hours ago, Itstrainingtime said:

This is very true. It's one thing to share thoughts with family and friends but when people's livelihoods are at stake it's an entirely different animal. 

So now, my forecast outlet is here. I'll be undercutting you a lot going forward, I'm quite sure of that.   

Lol, come on now, I went lower than many in the January storm forecast contest for MDT & won it with my 12.5 guess. 
You would have won the contest this time if we had done one this past weekend.

I look forward to the next chance!

[Blizzard of 93]

18z Euro brings a coating to many of us by tomorrow am with the overnight Clipper.

[Yardstickgozinya]

2 hours ago, Jns2183 said:

The historical Max and anomaly is March 1960. Maybe the month I dream about experiencing the most.

In March 1960, the Northeast saw a relentless pattern that produced 7 distinct measurable snow events for the Harrisburg (MDT) area, totaling that record-setting cumulative amount.
It wasn't just one "Superstorm"; it was a "parade" of systems that kept the ground white for nearly the entire month. Here is how that active March unfolded for Harrisburg:
March 1960 Storm Timeline (Harrisburg/MDT)
| Date | Snowfall Amount | Notes |
|---|---|---|
| March 3 | 10.5" | The primary "anchor" storm of the month. |
| March 10 | 1.8" | A cold-sector clipper system. |
| March 16 | 3.2" | Moderate overrunning event. |
| March 17 | 3.0" | St. Patrick's Day system. |
| March 22 | 2.0" | Late-season coastal influence. |
| Minor Events | 2.1" | Combined totals from minor dustings (March 4, 7, 8, 21, 24). |
| Total | 22.6" | (Catalog sum for distinct events) |


Prior to this month that winter had produced 27" of snow, similar to us now. But March was notice to all the new decade was a different beast

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Awesome. Thank.you for looking that up. I'm not sure how deep you went, but it sounds like this spring falls pretty short on 1960 analogs. I'm hoping to get back to work in the next ten to fourteen days, so 1960 doesn't sound that attractive anyways. 

[Yardstickgozinya]

1 hour ago, Blizzard of 93 said:

I think we have a long way to go until true Spring arrives this season. We have a few potential Winter events to track through next week. Then, we likely warm up for a week to 10 days. After that, the Teleconnections & MJO forecast indicate that mid March through at least early April could be a return to a colder pattern with the trough in the east.

I think we are tracking Winter storm chances through Easter week in early April this year. It fits the same pattern that we have had since around Thanksgiving. Any warm ups have been brief & i think that continues.

I think the seesawing is goeing to be anomalously brutal this spring. I foresee a spring with a fair amount of chances, with coastals and cold air nearby. 

 I know that you would love to see the whole month of March covered with snow , and that's okay. I personally just need the storm. The snow can melt before I wake up from resting for all I care.

Because of my line of work and other passios I won't root for snow once the growing season has started.   That doesn't mean that I won't enjoy it it happens, but there's far too many negative consequences for me to get excited at that point. 

[Yardstickgozinya]

17 hours ago, Jns2183 said:

I bit the bullet and downloaded state colleges record daily weather going back to 1894 and built a model to run 100,000 simulations. Got it to pass all over fitting tests, have a 99% percentile correlation, 94% interweek variability correlation, 98% intra- seasonal correlation based on auto-lag correlations. To have repeat of winter 1992-1993 and 1993-1994 back to back order not important it is a 1:1666 year event.

To repeat the first four years of the 1960s 1:768 year event.

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   I decided to edit my post, after I thought about it ,because I dont feel like I was able to convey my question without seeming like I was challenging your model. I'm helping my son move tomorrow.But when I get a chance, I'll send you a pm.

[Yardstickgozinya]

I was just looking up some data on late season events and I found this one that I don't believe i've heard talked about here. Obviously it's an anomaly and i'm not using it to prove any points here, but nevertheless, who would have thought you could have piled 21" of snow in Harrisburg, only a few days away from May. 

The April 27-28, 1928, blizzard was a record-shattering late-season storm that dumped up to 21 inches of snow on Harrisburg, PA, and over 35 inches in surrounding mountainous regions. It paralyzed central Pennsylvania, closing businesses, causing widespread power outages, and breaking trees due to the weight of the snow on foliage. 

 

Key Facts About the 1928 Event:

• Impact on Harrisburg: The city was "buried" under a 21-inch snowfall, described by The Patriot as one of the worst storms in history, bringing life to a complete standstill.
• Regional Impact: The storm hit the Mid-Atlantic and Appalachian regions, with Pennsylvania being hardest hit, though mountainous West Virginia saw up to 40 inches.
• Transportation Chaos: The storm stalled travel, including stranding the "Red Arrow" train for three days near Paoli, PA, with passengers forced to burn seat cushions for heat.
• Meteorological Significance: The storm was a "bomb cyclone" (rapidly dropping pressure) that hit in late April, making it one of the most devastating, late-season, and rare snow events of the 20th century

 

[MAG5035]

42 minutes ago, Yardstickgozinya said:

I was just looking up some data on late season events and I found this one that I don't believe i've heard talked about here. Obviously it's an anomaly and i'm not using it to prove any points here, but nevertheless, who would have thought you could have piled 21" of snow in Harrisburg, only a few days away from May. 

The April 27-28, 1928, blizzard was a record-shattering late-season storm that dumped up to 21 inches of snow on Harrisburg, PA, and over 35 inches in surrounding mountainous regions. It paralyzed central Pennsylvania, closing businesses, causing widespread power outages, and breaking trees due to the weight of the snow on foliage. 

 

Key Facts About the 1928 Event:

• Impact on Harrisburg: The city was "buried" under a 21-inch snowfall, described by The Patriot as one of the worst storms in history, bringing life to a complete standstill.
• Regional Impact: The storm hit the Mid-Atlantic and Appalachian regions, with Pennsylvania being hardest hit, though mountainous West Virginia saw up to 40 inches.
• Transportation Chaos: The storm stalled travel, including stranding the "Red Arrow" train for three days near Paoli, PA, with passengers forced to burn seat cushions for heat.
• Meteorological Significance: The storm was a "bomb cyclone" (rapidly dropping pressure) that hit in late April, making it one of the most devastating, late-season, and rare snow events of the 20th century

 

I’ve mentioned it somewhere in one of these threads in the past. I don’t believe that event dumped anywhere near that much snow in Harrisburg though. The NOAA NOWdata at Harrisburg/Middletown for those two days has over 3” of precip but only 2.4” of snow. 

It did dump those kinds of amounts back this way and on down the Apps thru WV and KY though. The local station here had something on it a few years ago. 

https://www.wtaj.com/weather/the-late-april-snowstorm-of-1928/

 

[Yardstickgozinya]

44 minutes ago, MAG5035 said:

I’ve mentioned it somewhere in one of these threads in the past. I don’t believe that event dumped anywhere near that much snow in Harrisburg though. The NOAA NOWdata at Harrisburg/Middletown for those two days has over 3” of precip but only 2.4” of snow. 

It did dump those kinds of amounts back this way and on down the Apps thru WV and KY though. The local station here had something on it a few years ago. 

https://www.wtaj.com/weather/the-late-april-snowstorm-of-1928/

 

That makes sense .I don't necessarily always buy into what Ai provides. I tried to find some more substantiated articles, about the event, in the Harrisburg area but, I couldn't find much.  I did read that apparently there's not a lot of historical data from within the affected areas cities.  I wouldn't think The Patriot news would be that ridiculously far off, but who knows. I didn't really dig deeply into the credibility of that article, or if it even exists. 

[pawatch]

21° when I went to bed last night, and when I got up this morning, it was 30° with just a light dusting of snow.

That’s not what NWS was calling for. Just appeared there wasn’t a whole of precipitation with the system.

Edit: currently snowing. 

[mahantango#1]

10 hours ago, Jns2183 said:

The median snow for Harrisburg after a February storm like the one the other day this late in February here is the past outcomes

25th 0.48
Median 2.66"
75th 6.28"

So likely all we get rest of season is a 1"-3"/3"-6"

She's just about done.

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Thyere's always hope.

[mahantango#1]

12 hours ago, Voyager said:

I don't have any hurrahs left in me... 

[Mount Joy Snowman]

Low of 24 but 32 when I left the house with no sign of snow. It’s funny, when I got home last night our kids were sledding out back. Half of our backyard holds snow exceptionally well, with the orientation of the slope and a couple large trees that are positioned perfectly to provide shade but not diminish precip. We even had a little swath of snow left from the big event more than a month ago when Sunday’s event occurred. 

[Itstrainingtime]

As expected, no snow fell overnight. Low was 25 but it's already up to 34. 

[mahantango#1]

[Itstrainingtime]

12 minutes ago, Itstrainingtime said:

As expected, no snow fell overnight. Low was 25 but it's already up to 34. 

Fortunately, NYC cashed in a bit and got an inch or two on top of the 2' they got on Monday. 

[mahantango#1]

Cooper and his grandmother are thinking ahead — way ahead — and preparing for a special snowball fight in July.

https://www.wgal.com/article/boy-keeping-snowballs-in-freezer-for-july/70468549

[Mount Joy Snowman]

GFS is on an island for Thursday but boy does it continue to look good for Monday, with varying degrees of support from other models, after which there are another couple of sporadic waves that may need watching.  Next week could be interesting before we finally turn warm for a bit. 

[Blizzard of 93]

7 minutes ago, Itstrainingtime said:

Fortunately, NYC cashed in a bit and got an inch or two on top of the 2' they got on Monday. 

Lol, just what they needed…

[Blizzard of 93]

No dusting or evidence of any flakes here last night either.

The Old line “Never count on a Clipper” rings true again.

[Itstrainingtime]

3 minutes ago, Mount Joy Snowman said:

GFS is on an island for Thursday but boy does it continue to look good for Monday, with varying degrees of support from other models, after which there are another couple of sporadic waves that may need watching.  Next week could be interesting before we finally turn warm for a bit. 

I mentioned yesterday that Elliott seemed interested in Monday. He is, but he's also insisting that it will be a light to possibly moderate event. GFS snow maps are way overdone. We shall see!

[Itstrainingtime]

2 minutes ago, Blizzard of 93 said:

No dusting or evidence of any flakes here last night either.

The Old line “Never count on a Clipper” rings true again.

Especially if you're south of the track.

[Blizzard of 93]

7 minutes ago, Mount Joy Snowman said:

GFS is on an island for Thursday but boy does it continue to look good for Monday, with varying degrees of support from other models, after which there are another couple of sporadic waves that may need watching.  Next week could be interesting before we finally turn warm for a bit. 

Early next week still looks very interesting on the GFS & most ensembles. Timing of the cold press from the approaching High & the strength of the wave will determine if we  have the chance to score meaningful snow.

Hopefully this trends favorably for us.

[Itstrainingtime]

2 minutes ago, Blizzard of 93 said:

Early next week still looks very interesting on the GFS & most ensembles. Timing of the cold press from the approaching High & the strength of the wave will determine if we  have the chance to score meaningful snow.

Hopefully this trends favorably for us.

I think early next week looks pretty darn good for something wintry. Details are days away from being figured out. 

[mahantango#1]

32 minutes ago, Blizzard of 93 said:

Lol, just what they needed…

Were the emergency snow shoveler's activated?

[Jns2183]

I think we have a long way to go until true Spring arrives this season. We have a few potential Winter events to track through next week. Then, we likely warm up for a week to 10 days. After that, the Teleconnections & MJO forecast indicate that mid March through at least early April could be a return to a colder pattern with the trough in the east.
I think we are tracking Winter storm chances through Easter week in early April this year. It fits the same pattern that we have had since around Thanksgiving. Any warm ups have been brief & i think that continues.

I agree with you in that I think there will be opportunities here. I'm just trying to set expectations in a proper manner. Realistically here are the return periods for different snow levels along with the last qualifying event. I would be hesitant to believe any storm snow maps going forward that paint more then 6" unless we get situated and a historically cold air mass, -25+ departure from normal, or we have a bomb perfectly of ocean city. I love l looking at some of the true late March / Easter bombs from before the satellite era. It's tough finding hourly data at times but I remember one from I think early 1940"s where it was snowing from DC to Harrisburg to Philly while raining in North Central to north east pa. It was 31-32 in dc while pushing 40 in Williamsport and Allentown. Pure dynamics driven as the low bombed out and retrograded. The ccb eventually made it to Allentown. The undisputed king of these storms is the 4 day March 18-21, 1958 storm where the low bombed out and was cut off. Snow was super elevation dependent and dynamic dependent. Philadelphia received 11.4" spread out over 4 days. Harrisburg was
1958-03-18: 0.0"
1958-03-19: 4.0"
1958-03-20: 4.7"
1958-03-21: 0.2"
Total (Mar 18–21): 8.9"

Morgantown, Pennsylvania 50".

I'm sure some of the high spots down in Adams and York counties did absolutely amazing.



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[Mount Joy Snowman]

While going by on the train this morning I noticed the river at MDT is really starting to flow nicely but boy is there one heck of a logjam of ice once you get to the turnpike bridge and points north.

[Jns2183]

   I decided to edit my post, after I thought about it ,because I dont feel like I was able to convey my question without seeming like I was challenging your model. I'm helping my son move tomorrow.But when I get a chance, I'll send you a pm.

What was your question? The reason the odds were so high there wasn't because it snowed a 100". It was because it did so essentially back to back years. You essentially have two 99th percentile winters happening in a rough. I accounted for the "stickyness" of winters through autocorrelation

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