Weather systems being upgraded to improve forecasts

NEW YORK -- Just two days ago New York City Mayor Bill de Blasio was talking doomsday.

"We are facing, most likely, one of the largest snow storms in the history of this city," said de Blasio.

But the forecasts turned out to be only half right. The storm developed 90 miles east of the expected track. New England and Long Island got nailed, but for Manhattan - and points south - it was no big deal.

The National Weather Service forecaster who predicted a crippling storm that never came for some ten million people tweeted a meteorological mea culpa.

But Dr. Marshall Shepherd, a past president of the American Meteorological Society, says no apology was necessary.

"I think the forecast were actually quite correct," said Dr. Shepherd. "If you take the northeast as a whole this is a historic storm for places like Boston and Massachusetts. We are talking upwards of 30 inches of snow in those places. Now New York is a different story. But I think the key to note there is the models were always a bit uncertain in that area."

Icy roads cause hundreds of crashes nationwide

"In situations like this you can't be a Monday morning quarterback on something like the weather," said DeBlasio.

Fresh in de Blasio's mind perhaps - just ten days before - forecasters underplayed the threat of an ice storm in the northeast. The system sent trucks jackknifing on the new jersey turnpike. Nine people died in accidents.

National Weather Service supercomputers are now being upgraded and will be ten times as powerful by October. But Dr. Shepherd says the key for forecasters and public officials is conveying uncertainty.

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Dr. Marshall Shepherd CBS News

"We do a nice job of it with hurricanes," said Dr. Shepherd. "You know that cone of uncertainty you see when a hurricane is making landfall, that is conveying uncertainty on either side of that hurricane track. Do we need something like that for these nor'easters? That will be a discussion point."

And keep this mind as far as forecasters go: That weatherman who tweeted out the apology, during Hurricane Sandy he was widely seen as a hero - credited with being the first to sound the alarm that the storm was headed to the Jersey Shore even when most other models had it drifting out to sea.

  • Jim Axelrod

    Jim Axelrod is the senior national correspondent for CBS News, reporting for "CBS This Morning," the "CBS Evening News," "CBS Sunday Morning," and other CBS News broadcasts.