Numbers match your mood: It's a miserable winter

Some days it seems that winter will never end. You reach a point where the never-ending cold and snow make your soul weary, and you wonder if this might be the worst winter you've ever experienced.

There are plenty of data points that could help validate that feeling. There was the recent morning where we woke up to a temperature of 1 degree Fahrenheit, or the foot of snow many of us had to shovel from our driveways just to get out and drive to work last week.

Or this: The National Weather Service reported there were 20 inches of snow on the ground on Monday. It's the first time we've reached that mark since March 1999.

These extreme low temperatures or big snowstorms can make for a miserable day. But the true measure of misery isn't those singular low points, it's the number of those miserable days strung together.

Here's some more data: We've had at least a trace of snowfall on 15 out of the last 17 days.

As of Thursday, temperatures have dipped below freezing for 24 days in a row, and there has been at least an inch of snow on the ground for 15 straight days. None of those are all-time records, but they certainly contribute to a feeling of a long winter.

But what about the big picture? Every winter can't be the worst winter of all time. How can we objectively measure how bad each one has been?

To answer that question, I turned to a pair of weather researchers, Steven Hilberg and Barbara Mayes Boustead. They have spent the last few years developing a system that attempts to boil all of the winter weather factors down to a single number.

But Hilberg, a senior climatologist at the Midwest Regional Climate Center in Champaign, Illinois, bristles at the idea of calling it a "misery index."

"It's a winter severity index," Hilberg said. "Just because it's cold and snowy doesn't mean people are miserable. I personally enjoy winter."

Some of us will have to agree to disagree on that point.

The system, officially dubbed the Accumulated Winter Season Severity Index (AWSSI) looks at the intensity and persistence of cold weather, the frequency and amount of snowfall, and the amount and persistence of snow on the ground.

A score is tabulated based on each day's weather observations for individual cities, and it accumulates throughout the winter season. Those raw scores then determine where each winter ranks on a five-point scale: mild, moderate, average, severe or extreme.

The idea is to put each winter into historical context. This winter may seem unusually harsh in part because recent years have been more mild. In fact, for almost three-quarters of the places studied, the winter of 2011-12 was the mildest on record. That would include Rochester.

How does this year match up? As of Feb. 10, Rochester's AWSSI index was 558. Last year at this time, it was 641.

"Both scores are at the upper end of the average category," Hilberg said. "but last year, Rochester's winter ended up ranking in the top 20 percent, and I expect this season will also drive into that 'severe' category by the time it's over."

Hilberg and Boustead ran the numbers for about 50 locations in the U.S., looking at weather reports for each day from 1950 to 2013, and they're actively monitoring about a dozen cities this winter. It's a complex manual process, and they're working on an interactive online system that would automate the tracking of winter weather in hundreds of cities.

They've published their methodology, so if you're a data cruncher, you can download daily weather totals for Rochester back to the 1950s, fire up your spreadsheet, and run the numbers yourself.

Of course, weather severity is relative to where you live. "A 6-inch snowfall in Atlanta is a major event," Hilberg said. "In Rochester, it's just another day."

And just because we're having a hard winter here doesn't mean the rest of the country is in the same situation.

"This year, Minnesota, Iowa and Illinois are having average winters, but most of the Northeast is pushing into the extreme category," Hilberg said.

In some places, those extremes have been driven by historic snowstorms, like the lake effect snow that buried Buffalo in November, or the trio of storms that have battered Massachusetts.

"In Boston, through about the 24th of January, it was a nothing winter," Hilberg said. "They were in the lowest and most mundane category we have. But then in two weeks, they've shot up to the most severe category we have."

Here in Rochester, we haven't had those types of singularly historic events. What we've had has just been a long steady slog of snow and cold weather.

Misery is largely a matter of personal perception, and the contributing factors are things that meteorologists don't measure: white-knuckled commutes when roads are slick and visibility is low; wet feet that never get dry after trudging through the slush; the back-breaking work of shoveling a driveway, clearing snow from a roof, or scraping ice from your windshield on a bitterly cold morning.

When one massive storm comes, like Buffalo's 2 feet of snow in November, folks hunker down then band together to dig out. The suffering brings a sense of community, and eventually a feeling that you've overcome the worst that winter has to offer.

But when you're instead confronted with day after day of cold and wet, with the cycles of freezing and thawing weeks apart and glimpses of sunlight few and far between ... well, that's a pretty good definition of misery.

Boustead's work on historical weather research was driven in part by her interest in Laura Ingalls Wilder and her Little House on the Prairie book series. In particular, her book The Long Winter, which recounts the 14-year-old girl's experience in South Dakota during the severe winter of 1880-81. Wilder described a terrifying Dakota blizzard that howled and screamed for weeks on end. Short on fuel and food, her father braved the storm to find help and got stranded when the snow became impassable. They were all fortunate to survive.

"One of the big questions about the Long Winter of Laura's experience was to answer this seemingly simple question: How bad was it, and was it the worst winter on record?" Boustead writes at her blog. "To answer that, we have to be able to define 'bad.' "

Boustead, a National Weather Service meteorologist based in Omaha, realized that if she wanted to answer that question, she'd have to create a method that let her answer it.

She found that it ranked as the second-most extreme of all winters where data was recorded. That initial curiosity led to the development of the AWSSI with Hilberg. They spent several years compiling data, performing analyses, and fine-tuning the methodology to provide historical comparisons of each winter season.

Although she differs with her colleague in one regard.

"I personally would call this a misery index," Boustead said.

On that point, I think we can all agree.

SLAHMAN@Gannett.com

Twitter.com/SeanLahman

Rochester's best and worst winters

The Accumulated Winter Season Severity Index measures the severity of winter weather by analyzing the intensity and persistence of cold weather, the frequency and amount of snow, and the amount and persistence of snow on the ground. The index was developed by meteorologists Steven Hilberg and Barbara Mayes Boustead, who analyzed daily weather records for selected cities back to 1950. The table below shows the most and least severe winters in Rochester from 1950-51 to 2013-14.



To learn more

• Information on the Accumulated Winter Season Severity Index: http://bit.ly/MRCC-AWSSI.

Meet Sean Lahman

Lahman covers data-based stories as part of the Democrat and Chronicle's watchdog team, and maintains RocDocs.com, a collection of databases and data visualizations.