The Truth Behind The Mystery Of Weather Forecasting

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Ah, winter. Remember that? Well, if for some reason you had forgotten, last week certainly provided a useful reminder.

Of course, if you live in New England, you got your reminder a few days earlier with a classic Nor’easter.

Yes, that’s the way the National Weather Service (“NWS”) spells this famous type of storm. These weather events feature notorious low pressure systems that travel up the eastern seaboard. They’re so named because the winds along the coast come from the northeast.

Nor’easters are not limited to the winter. The NWS tells us these storms generally occur in their “most frequent and most violent” form between the months of September and April. Like a couple of weekends ago, it’s the winter versions that tend to capture headlines.

If they hit at the right time of year and the right location, they can have a dramatic impact on our own local weather. The prevailing winds within the Greater Western New York Region generally come from the west and the southwest. These winds are responsible for the vast amount of lake effect snow off Lake Erie. When the winds are particularly strong, our communities, though some 70 miles from Lake Erie, can see this form of snow falling in our backyards (and our front yards and all the other yards around us).

Winds coming from the northeast generate lake effect snow from Lake Ontario. These winds are generally weaker than the prevailing westerly winds, so Lake Ontario lake effect snow mostly impacts just those next to the shore.

Except when there’s a Nor’easter. Those often very strong winds can push the Lake Ontario snows further to the south. That includes us.

The trouble is, like I said, the Nor’easter has to be in the right place at the right time of year. Therein lies the rub.

Nor’easters are difficult to predict. Any slight shift can mean the difference (along the populous megalopolis from Boston to Washington DC) between a rain event, a snow event, and no event at all. Because of this, weather models can be all over the place.

Which brings us to the question of the day. It all started with an email I got from a classmate of mine (who lives in Connecticut) regard their recent Nor’easter (which, by the way, didn’t impact us.

This was his comment: “We all picked the wrong professions. Weather reporters for this storm seriously said, ‘One model predicts 4-1/2 inches possible, while the European model predicts 14-1/2 inches.’ If my work allowed that kind of tolerance, they’d be out of business…”

I replied that, up here in Lake Effect Country, experience shows the European models usually rule (there’s a reason for that which I’ll explain in a moment). His response was, “So, like so much else these days, the American model in comparison just plain stinks.”

It’s not quite that simple. For one thing, when it comes to all these models (and there’s more than just two), weather forecasting is more like man vs. machine. The “American” model (its official name is “The Global Forecast System”) is run by the NWS. In reality, it’s run by a supercomputer the NWS maintains.”

The “European” Model (officially ‘The European Center for Medium Range Weather Forecasts”) is made up of groups from nearly three dozen countries. Its computers are more powerful.

There are two other broadly used models (the “British Model” and the “Canadian Model”), but the American and European models are the most preferred. The American model handles forecasts from 16 days out, while the European model only goes out 10 days. The European model is more accurate within two days (but not all the time). The American Model is free. The European Model costs $250K for a commercial license. I guess you get what you pay for.

Most professional meteorologists look at multiple models and often add their own overlay. This is where the human element comes in. They use all the supercomputer processed output data and assess what it all means. In essence, they read the binary tea leaves and interpret them. In the end, it all comes down to an educated guess.

I picked up all this when I set up my own weather station during high school. I still have the records somewhere (and, yes, they should include data for the “Blizzard of ‘77”). Incidentally, my amateur status very nearly got upgraded to professional (as in “on TV”) meteorologist. I came in second at the Channel 13 audition in the mid-1980s. I thought I had a leg up with my Astronomy and Physics degree because the previous Channel 13 weatherman was Bill Gutsch, an astronomer-turned-weather-forecaster who ended up with a long-term gig on Good Morning America.

Incidentally, I called Bill just before my audition. I knew him from his days as head of the Strasenburgh Planetarium. The first thing he told me he was actually more excited to move to New York City because he had the opportunity to be named Chairman of the Hayden Planetarium. The second thing he told me was to not accept the job if I wanted to do other things in my life. He said he left because they wanted him to quit the Planetarium.

In the end, I didn’t have to turn down the job. Channel 13 picked Kevin Williams over me. This made a lot of sense since he had a meteorology degree from Cornell. Of course, he also had his own business, and, despite his popularity, that might have been the reason he eventually left Channel 13.

By the way, and this might be obvious to you, the shorter the forecast, the more accurate it is. This may sound like a silly thing to say, but if you’re hiking, reading the clouds is critical (and may mean the difference between life and death depending on the terrain you’re on). It’s not the clear skies you’re concerned about. It’s the developing cloud formations, especially oncoming thunderstorms.

I understood the practical impact of all this weather lore as a Boy Scout leader. While leading a ten-mile hike through Gettysburg, I noticed the approaching clouds. They weren’t friendly. Just before we reached Seminary Ridge (i.e., the “high point of the confederacy”), I could tell we had less than ten minutes before the downpour (and the thunder and lightning) would hit.

Some background first. Seminary Ridge was about a mile away from the end of the hike at McClennan’s headquarters at the bottom of the hill. The good news: It was all downhill. The bad news: It was all open terrain, not an ideal place to be in the middle of a raging thunderstorm. The worse news: The boys were tired, slow, and not inclined to take direction.

What to do… what to do?

A thought occurred to me. We were about to follow the footsteps of Pickett’s Charge. Now, I knew the “charge” started off as a walk, but the boys didn’t know that. I lured them into wanting to reenact Pickett’s Charge with an added incentive: the first one to McClennan’s Headquarters would win a prize.

As a final nod to the human element with regard to weather forecasting, I applied a bit of reverse-psychology, I warned them not to run too fast “because it was all downhill.”

Bam! They took off. They didn’t need to be inspired by the sudden sharp peal of thunder to the immediate west (although it did inspire me).

We all made it back to McClennan’s before the wild rain and lightning hit.

Imagine how a supercomputer would have handled this?

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