Central PA Winter 25/26 Discussion and Obs

[Jns2183]

Charlotte had 11" of snow on 0.51" qpf

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[Jns2183]

Imagine being in Raleigh?

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[ChescoWx]

We start February as we ended January with well below normal temperatures. I am working on completing the overall Chester County summary for January but at least here in East Nantmeal this January was the 4th coldest and 3rd snowiest across the 23 years I have been recording weather observations at this location. This well below normal stretch of temperatures looks to continue for at least the first 10 days of February. Today will be our 9th straight day with below freezing high temperatures. We do moderate through Tuesday with our best shot at getting above freezing being Tuesday. The current NWS forecast has a high here in EN of 30 degrees. There could be a few light snow chances over the next week with the first potential on Tuesday night a more likely shot by Friday and another chance possibly by next Sunday. For those on Team Snow the good news is February is on average our snowiest month of the year with East Nantmeal averaging 13.3" of snow in a typical 2nd month of the year.

[Superstorm]

Charlotte had 11" of snow on 0.51" qpf

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That’s better than 20:1. Nice fluff factor!


.

[Voyager]

2 hours ago, mahantango#1 said:

There's a scraper on Front street in the burg. The one by the UPMC hospital. Trouble is most trucks are too big height wise to fit under it.

Lol...

I did actually fit under it when I was driving the buses. 

[Blizzard of 93]

12z GFS bumped a little north & gets 1 to 2 inches by Wednesday morning to most of CTP.

[mitchnick]

1 hour ago, Jns2183 said:

Imagine being in Raleigh?

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https://www.outerbanksvoice.com/live-traffic-cams/

[Jns2183]

I've created this

The Winter Severity Metric (WSM) is designed to quantify the "harshness" of a winter day on a scale from 1 to 10. While a thermometer tells you the temperature, the WSM tells you the experience—combining the biting cold with the physical reality of snow on the ground.
How the Metric Works
To ensure the scale is meaningful for the Middletown-Harrisburg region, the metric is calculated using a weighted average of four key weather variables. Each variable is first mapped to a 1–10 sub-score based on historical deciles (for temperature) and intensity thresholds (for snow).
Snow Depth (40\%): The primary driver of winter severity. A deep snowpack transforms the environment and complicates daily life more than any other factor.
Max Temperature (25\%): Weighted more heavily than the low, as the "high" temperature dictates how much (or little) relief there is during daylight hours.
Snowfall (20\%): Captures the "active" severity of a storm event.
Min Temperature (15\%): Accounts for the intensity of the air mass, particularly during overnight deep freezes.
The Scale:
Level 1-3: Mild winter days (Spring/Fall-like).
Level 4-6: Typical winter days (Cold, perhaps a light dusting).
Level 7-8: Significant Winter (Heavy snow or extreme cold).
Level 9-10: "Deep Winter" (The absolute historical extremes).

When we calibrate the Winter Severity Metric (WSM) specifically for the "core" winter window of December through March, the scale shifts to focus on the relative intensity of winter conditions. In this view, a score of 10 represents the historic extremes of the Harrisburg winter, while a 1 represents the mildest days that occur during the winter months.
The Averages: Benchmarking a "Normal" Winter
Based on historical data from 1899–2025, here are the baseline scores for a typical winter period in Middletown-Harrisburg.
| Timeframe | Mean Score | Median Score |
|---|---|---|
| Winter Day | 3.45 | 2.98 |
| Winter Week | 3.51 | 3.13 |
| Winter Month | 3.46 | 3.23 |
* Interpretation: A "median" winter day (roughly a 3.0) is typically clear and cold but lacks significant snow. Any day or week scoring above a 5.0 is considered "more severe than average," and scores above 7.0 are reserved for major winter events and extreme cold snaps.
Top 10 Lists (Dec–Mar)
1. Top 10 Winter Seasons (Full Season Average)
Calculated as the average daily WSM from December 1st through March 31st.
* 1917–1918 (5.15): The all-time severe winter; dominated by the #1 month and multiple top weeks.
* 1977–1978 (5.08): Defined by relentless snow depth that lasted through much of February.
* 1904–1905 (5.07): An early century powerhouse with consistent arctic air.
* 1993–1994 (4.96): Famous for repeated high-impact ice and snow events.
* 1960–1961 (4.92): Contained the single most severe 7-day stretch in history.
* 1969–1970 (4.91): A winter of extreme persistence in snow cover.
* 1935–1936 (4.67): Record cold February coupled with significant snowpack.
* 1919–1920 (4.63)
* 1963–1964 (4.50)
* 1995–1996 (4.46): Driven primarily by the legendary January '96 blizzard.
2. Top 10 Winter Months
* January 1918 (7.59)
* February 1978 (7.50)
* January 1970 (7.46)
* February 1936 (7.11)
* January 1994 (6.78)
* February 1905 (6.69)
* January 1945 (6.61)
* January 1961 (6.57)
* January 1925 (6.49)
* February 1994 (6.48)
3. Top 10 Winter Weeks (7-Day Non-Overlapping)
* Jan 20 – Jan 26, 1961 (8.70): The peak of winter intensity in local history.
* Jan 22 – Jan 28, 1918 (8.68)
* Jan 29 – Feb 04, 1966 (8.57)
* Jan 07 – Jan 13, 1996 (8.48)
* Jan 29 – Feb 04, 1961 (8.46)
* Dec 12 – Dec 18, 1917 (8.43)
* Feb 07 – Feb 13, 1936 (8.39)
* Jan 06 – Jan 12, 1970 (8.36)
* Jan 19 – Jan 25, 1936 (8.28)
* Jan 15 – Jan 21, 1918 (8.27)
Commentary
* The "Relentless" vs. "Extreme" Difference: A season like 1918 is the champion of "Relentless" winter (ranking #1 overall), while a week like January 1961 represents "Extreme" winter. In that week, temperatures barely moved, and the ground was buried, resulting in an average severity nearly 3 times higher than a normal winter day.
* Modern Context: 1994 and 1996 are the only winters from the last 30 years to break into the all-time Top 10 seasons. The 1994 season was particularly unique because it placed two separate months (January and February) in the Top 10, indicating a long-duration severe winter rather than a single fluke event.
* Threshold Dominance: Because Snow Depth is weighted at 40\%, months like February 1978 score extremely high. Even if it isn't the coldest month on record, having a foot of snow on the ground for 30 straight days is the most significant factor in creating a "Deep Winter" experience.


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[Mount Joy Snowman]

I heard some stat about State College having 8 straight days with temps remaining below 20 degrees (think it was just broken this afternoon), which is the longest such stretch since 1893, or something to that effect.  Wild.

[Jns2183]

Based on the Winter Severity Metric (WSM) and the recent weather data for Harrisburg (including the record 11" snowfall on January 25th), here is how the last seven days and the overall month of January 2026 rank historically.
January 2026: Daily Standings
The 11" snow event on the 25th was the clear heavyweight, immediately breaking into the Top 100 most severe days in the record (Rank 62 out of over 15,000 winter days).
| Date | WSM Score | Daily Rank (All-Time) | Commentary |
|---|---|---|---|
| Jan 25 | 8.91 | #62 | Extreme: Record snow + high depth. |
| Jan 26 | 7.20 | #704 | Severe: Deep pack persistence. |
| Jan 27 | 5.96 | #1971 | Significant: Cold with standing snow. |
| Jan 28 | 5.37 | #2662 | Moderate: Temps began to recover. |
| Jan 29 | 6.46 | #1370 | Significant: Light snow / secondary wave. |
| Jan 30 | 6.67 | #1120 | Significant: Deep cold return. |
| Jan 31 | 6.47 | #1364 | Significant: Persistent pack. |
Weekly Ranking (Jan 25–31)
The final week of January averaged a WSM of 6.72.
* Rank: It stands as the 119th most severe week in history.
* While the daily peak of the 25th was historic, the gradual temperature recovery in the middle of the week kept it from breaking into the all-time Top 10 weeks (which usually require sub-freezing highs for all 7 days).
Monthly Ranking (January 2026)
This is where the 2026 season truly shines. Driven by the massive storm and a consistently cold pattern throughout the month:
* Monthly Average WSM: 6.72
* Historic Rank: #6 all-time
January 2026 now officially joins the ranks of the "Great Winters," sitting just behind legends like January 1994 (#5) and January 1918 (#1). It is the first time in the 21st century that a winter month has cracked the all-time Top 10 for severity.





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[Jns2183]

For fans of deep winter we just experienced a true masterpiece

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[WmsptWx]

3 hours ago, Jns2183 said:

Imagine being in Raleigh?

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I don't have to. That's Huntingdon. Just in NC.

[Festus]

For Lancaster, looks like Tuesday is our only chance to get above freezing in the next 7 days at least.  If we don't get there and the rest of the week goes as forecast, that would break the existing record of 15 straight days below freezing endured in both 1961 and 1979 with records going back to 1914.

Historic cold indeed.

https://lancasteronline.com/news/local/lancaster-county-breaks-14-day-streak-of-temperatures-under-freezing-which-last-happened-in-1979/article_fce945ba-f5a3-11e7-92db-938a3f30ea7c.html

[Jns2183]

If someone else has a better idea for weighting or calculated a winter metric let me know. Looking at the forecast for next week the 14 day period starting 1/24 and ending 2/6 has a great shot at hiting 6.89 which would be in the top 2.5% of all 14 day periods going back to 1890

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[Jns2183]

I think both storms next week have the opportunity to surprise with some high ratios it does not take much to get a 4_-6" fluff bomb. Those were the bread and butter in the 1960s with usually 6-8 storms training in the winter

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[str8liner]

1 hour ago, Jns2183 said:

For fans of deep winter we just experienced a true masterpiece

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I am a fan of it but I will be happy when my furnace finally stops running 24/7.

Been a while since we used this much heating oil.

[SnowPlowGuy88]

24 minutes ago, str8liner said:

I am a fan of it but I will be happy when my furnace finally stops running 24/7.

Been a while since we used this much heating oil.

Agreed. Had a new furnace installed at the end of December. Tank was topped off just prior, in early November, at 250 gallons. We are currently just about at the half full mark. Have never used more than 100-125 gallons in a winter until this one. New windows are now on the menu, once the furnace is paid down a bit. 

[Blizzard of 93]

CTP is on board for our 2 chances at light snow this week.

KEY MESSAGES...
1) One more night of Advisory-level wind chills tonight

2) Light accumulating snow possible late Tuesday night into Wed
(mainly southern PA)

3) Light accumulating snow is possible again Fri-Sat, followed
by gusty winds and another shot of Arctic air for next weekend

 

[canderson]

Strong, big winds likely next weekend.  

NWS SPC has all of PA already on mod risk of high winds. 

[Jns2183]

Strong, big winds likely next weekend.  
NWS SPC has all of PA already on mod risk of high winds. 

It by some good luck we can pull out 4"+ combined this week, those tundra winds combined with artic cold will give the deep winter the proper send off it deserves as temperature moderate slowly.

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[Blizzard of 93]

 

The 18z GFS Ai has an interesting look out in fantasy land on PD weekend.

[Blizzard of 93]

Just now, Blizzard of 93 said:

 

The 18z GFS Ai has an interesting look out in fantasy land on PD weekend.

Surface is intriguing as well…

 

•  
•  

[Itstrainingtime]

People in North Carolina seem bewildered that they lost so much of their snowpack on a 30 degree day. Full sun + powder snow = no chance of lasting. 

So grateful for all of the ice in our pack. That's what's maintaining our landscape.

[Jns2183]

 

The 18z GFS Ai has an interesting look out in fantasy land on PD weekend.

The GFS AI thinks Canada is going on a tropical vacation while Harrisburg sits in the hallway getting dripped on by a leaky ceiling. It's not a winter wonderland; it's just 'Gray and Gross'—the weather version of an unseasoned potato

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[ChescoWx]

Below is the January 2026 Climate Summary for the Philly burbs of Chester County PA Area. This January finished as the 29th coldest with 134 years of climate records. This December/January is the 21st coldest start to a winter season on record. Additionally, we have received well above normal snowfall to date with almost double normal snow to date. East Nantmeal recorded the 15th greatest January snow total and the most since 2016.

[MAG5035]

On 1/31/2026 at 12:14 PM, Voyager said:

Good God... 

I know you guys love winter, but really, when is this pattern going to flip or relax, and why has it been so persistent? 

 

This winter has been tracking similarly to the last real consistently cold winters that we had back in 13/14 and 14/15, especially the latter. Main drivers then were heavily Pac influenced with a strong and persistently negative EPO and WPO much like we’ve had most of this winter so far other than when we warmed up for a couple weeks in early January. That alignment directs a continental source of cold air from Canada with no Pacific modification. The 13-15 winters achieved that without much help from any -NAO/AO, something we actually have had a good bit of this winter, and currently. The result has been a lot of cold in the east, and a historicially bad winter snow-wise in some parts of the west to date. 

So with that said, I’ll offer at least a little bit of hope. Starting to eye the following week after this week for some kind of period of modification after we probably get whacked with a couple days of arctic air comparable to what we just had next weekend. Looking at teleconnection forecasts right now, there’s a pretty sizeable shift progged to occur in the Pac realm occurring around the timeframe of that clipper and ensuing arctic shot. EPO and WPO both reverse to positive, and the monster +PNA we have reverses to negative. That combo will almost certainly inject Pacific modified air into the CONUS to some degree. How much negative NAO holds will probably have a hand in how that works into our part of the country. Nothing really reverses the -NAO/AO but some ensembles neutralize a bit more than others. So there could be some resistance here, especially with a solid snowpack in the Northeast. Resistance could in fact end up breeding more snow/mix events in our neck of the woods. But I’m currently thinking we’re looking at a milder pattern overall during that timeframe either way. And you can see the op runs of the GFS/Euro in the longer range sort of reflecting that shift. 

This week prior to the clipper won’t be all that bad temp-wise either, at least during the day. We will continue to have very cold nighttime lows with a deep snowpack and mostly fair weather (other than maybe Wed for some). 

[Blizzard of 93]

20 minutes ago, MAG5035 said:

Resistance could in fact end up breeding more snow/mix events in our neck of the woods

10000000 % this….

Let’s throw some moisture at this block.

Warm up & snow… let’s go!

[MAG5035]

8 hours ago, Mount Joy Snowman said:

I heard some stat about State College having 8 straight days with temps remaining below 20 degrees (think it was just broken this afternoon), which is the longest such stretch since 1893, or something to that effect.  Wild.

UNV got to 25ºF today, with similar temps around town up there. So it stayed at 7 days, which is still tied for the 2nd longest streak to that 1893 streak of 10 days. AOO broke their longest yesterday (that station only goes back to 1950) and added another day today only reaching 18ºF. 

Quote

.CLIMATE...
State College tied the second longest run (7) of consecutive
days with max temp staying <= 20F for the period 1/25 through 1/31).
The last time this occurred was post-Christmas 2017 (12-28-2017
to 01-03-2018). The longest run of 10 days occurred in January
1893 from the 11th-20th. It will be a top 3 coldest last week/7
days of January (mean temp 1/24-1/31) for State College.

January ended up drier and colder than normal for nearly the
entire Commonwealth. It is worth noting that January 2025 was
comparable to January 2026 in terms of temperatures (it was actually
slightly colder last January at Harrisburg, State College, and
Johnstown compared to this year).

 

That’s interesting that for the month as a whole, last January was actually colder.