Posting in Environment
The federal government stopped. The mail service stopped. But for Washington's double-header snowstorms this month, the meteorologists got it right.
Given all the snow-related uncertainties here in Washington (in the last 14 days, my mail has been delivered twice, trash picked up once and recycling picked up zero times), it’s been comforting to know I could count on the weather forecasters.
Meteorologist Steve Zubrick, Science and Operations Officer for the National Weather Service’s Baltimore/Washington Weather Forecast Office (part of National Oceanic and Atmospheric Administration), assured me that his time in the limelight wouldn’t last—the very next snow forecast, if incorrect, could send him tumbling from the winner’s circle. But for now, Zubrick and his colleagues shine. I talked to him earlier this week.
You guys were right on in predicting the storms this month. Are you getting better at forecasting?
It’s gotten better through the years. The system is called a global observation system. The biggest change over the last 20 years is the increase in observation from the array of satellites, which now provide nearly two billion observations of the atmosphere a day. We also have a global system of in situ—observations taken at the surface of the earth or from weather balloons or planes. If you fly on a commercial airplane out of Dulles, there’s a high likelihood the plane is recording winds as it ascends, which is being sent to a central system. All that data is compiled to make a snapshot of the current state of the atmosphere. We call it the telecommunications gateway. It’s a huge job to get all that information. Then the Weather Service interprets it.
It was really amazing. Forecasts said the snow would start at a certain time, and it started exactly at that time.
It was pretty impressive. I’ve been here since ’92, and it was the most confident I’ve seen us go out with winter storm conditions. We had a winter storm warning out 30 hours in advance. The storm warning started at 10, and it started snowing at 10.
The stakes seem to be higher these days—you’ve got airlines, governments, big offices, all waiting for the forecast. This time, flights and schools were cancelled before it even started snowing.
We put together a forecast and do briefings for government agencies and the airports. For the big storms, knock on wood, we do pretty well. These were truly historic storms—December and early February—and this area is just not geared up to handle these storms. It’s the smaller events that are more challenging. And we haven’t solved everything yet, so there will still be systems where you miss things. The thing that keeps me up at night in the winter is getting a couple hundredths of an inch of freezing rain when we’re not expecting it, and there are not [salt] trucks out. And people head to work, and there’s ice on the ground.
But in the meantime, we all think meteorologists are terrific.
Everybody loves meteorologists now, until the next bad forecast, which will inevitably happen. The problem is, with these big storms, I think we unrealistically raised expectations because we got it right. In finance, if you’re a stock analyst, you have to manage the expectation of your customers. Our customers are you. I’d be lying if I said we’d be that good every snow system.
When wasn’t it that good?
January 25, 2000, we had over a foot of snow in Washington, and the day before, we were calling for mostly cloudy skies and an inch of snow. Do you remember that?
I don’t remember the forecast.
We do. We were feeling pretty good about ourselves, that the storm would stay out to sea. Since the mid-‘40s we’ve used numerical prediction models, which have grown more sophisticated in how they handle the atmosphere. So we used several models, but it turned out all the models were wrong. The field of ensemble modeling was born 15 to 20 years ago—you look at as many models as you can to form an ensemble. In 2000, some of the guys running the ensemble were onto [the storm], and that would have been good information for forecasters to have, but we didn’t. From our miss, that’s what really launched ensemble forecasting.
So you use ensemble forecasting now?
Yes. With these storm systems that occurred last week, it serves as a testament to our current capabilities and the advancement, that we were able to say for certain the time and amount of snow. The forecasters were very confident, because all the ensembles were saying the same thing.
Feb 18, 2010