Friday, February 04, 2011

Ice Day

When I woke up this morning and saw that that the "one to three inches of snow" on the ground that the television forecasters had breathlessly been predicting over the last few days hadn't materialized, I was a bit disappointed. (And I wasn't the only one; my son was pretty bummed, too.)

But I wasn't exactly surprised. I was in fact beginning to have my doubts about the possibility of snow over the course of the day Thursday as I continued to check the hour-by-hour forecasts on The Weather Channel. At first the wintry precipitation was expected to begin at 3 pm. Then it was pushed back to 5 pm. Then 9 pm. Then 11 pm. Then 1 am. You get the point.

As it turned out, we did start getting precipitation in the form of freezing rain late Thursday night. But the transition from freezing rain to sleet and then to snow that we had been told to expect never occurred. Thus, no snow with which to build snowmen or have snowball fights.

As Channel 13's Tim Heller and the Chronicle's Eric Berger explain, temperatures in the atmosphere over Houston simply did not become cold enough at all levels for any snowflakes that might have formed in the upper elevations to remain in that state before they reached the ground.

The fact is, in spite of all of the advances our civilization has made in terms of monitoring (e.g. satellites and Doppler radar), modeling, and forecasting technology, we still cannot predict with absolute certainty something as complex and variable as weather. That's why when we speak of weather we speak in probabilities - a "60 percent" chance of rain, a "partly-cloudy to mostly-cloudy" sky, high temperatures "in the mid-60s," a "cone of uncertainty" for hurricane landfalls. Perhaps we should begin referring to meteorologists as "weather-guessers," because that's essentially what they do: they make educated guesses as to future weather events based on the past history, the current information and the forecasting methods of weather that are currently available. Sometimes they're right. Sometimes they're not.

Thar being said, meteorologists were absolutely correct in their prediction of icy precipitation this morning. As such, the decision to close the schools, shut down government services and tell people to take the day off or work from home was a good one. Driving conditions this morning were especially treacherous, as the freezing rain caused bridges and overpasses to ice over. Houstonians (myself included) are simply not accustomed to driving in these kinds of conditions, which is why there were an estimated 800 automobile accidents in the city between late last night and late morning today.

The simple fact is that snow is exceedingly rare in Houston because of the city's geographic location. Conditions have to be absolutely right for it to happen. Therefore, I've learned not to believe weather reports predicting snow until I actually see the flakes falling.

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