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!


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[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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