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Posted at 12:12 PM ET, 01/18/2013

National Weather Service’s head-scratching Winter Storm Watch for Thursday’s non-storm


The National Weather Service office in Sterling was forecasting 4-6 inches of snow inside the D.C. beltway on Wednesday for the Thursday storm. No snow fell. (National Weather Service)

When I saw the words “Winter Storm Watch” for “in excess of 5 inches” of snow Thursday scroll across my computer screen Wednesday morning, I couldn’t believe my eyes. I was poring over the latest computer model data and debating, in my mind, whether we would get even one inch of snow.

Ultimately, most spots in the Washington, D.C. area didn’t see one flake. Suffice to say, this particular forecast emerges as one of the worst issued for a winter weather event by our local (Sterling, Va.) office of the National Weather Service (NWS) in recent memory. It misled and confused the public, and probably contributed to needless expenditures for salt/chemical treatment of roads.

So how and why was the watch issued?

According to the NWS office in Sterling: “a Winter Storm Watch by definition is issued to alert the public and transportation planners that there is a 50 percent chance of 5 inches or more of snow.”

Chris Strong, the warning coordination meteorologist at the Sterling office, defended hoisting the watch, stating computer model forecasts supported a hefty snowfall.


Snowfall totals from Thursday’s storm. The closest accumulating snow was observed in Charlottesville and and St. Mary’s county. (National Weather Service)

“When the watch was issued the day before the storm, many of the meteorological models that simulate the atmosphere were suggesting 5 or more inches of snow in D.C. right at evening rush hour on Thursday,” Strong said.

But we reached a much different conclusion analyzing the same models. We called for just a 45 percent chance of 1 inch or more of snow. Wes Junker, our winter weather expert, stressed the uncertainty in the forecast.

“The storm has the potential to produce shovelable snow accumulations but also has the potential to skirt us to the south giving us only light precipitation or even none at all,” Junker wrote.

He said the chance of 4-5 inches of snow was just 10 percent.

Despite our strong belief that the NWS forecast was an outlier, as a major news outlet and NWS media partner, we report its official watches, advisories and warnings (as a matter of routine). So we posted the watch shortly after it was issued on this blog as well on our social media feeds. But we took the unusual step of publically disagreeing with it.

“Our opinion is that [the watch] is premature and overdone, and that current available information does not support this forecast,” I wrote at 11:42 a.m. Wednesday morning, about 20 minutes after the watch was issued.

It is the first time I can recall publically disputing an official NWS winter weather product. I stress that in the overwhelming majority of situations, we are on the same page with the NWS since it typically does stellar work. But this case was different, and we weren’t alone in arriving at this conclusion.

“Faulty guidance and poor forecasting methods led to much of the hype surrounding the snow “storm” that would “hit” Washington,” blogged Doug Hill, ABC7’s chief meteorologist. “We passed along the WINTER STORM WATCH. We did not issue it.”

I spoke to other broadcast meteorologists at NBC and CBS who felt similarly.

I am not privy to the decision process that led to the watch. No doubt erring on the side of caution was a key motivation, especially since the region hasn’t experienced accumulating snow in a long time, and our last collective memory is Commutageddon (January 26, 2011).

But NWS officials need to consider their forecasts and watches carry tremendous weight and reach the masses. The public, emergency managers and transportation planners take them very seriously. And word travels instantly via radio, internet (social media!) and television. As soon as a watch for “the potential” for 5 inches or more of snow is issued, within hours, a huge segment of the metro area expects a major snowstorm.

I overheard countless conversations on metro, in restaurants and on the street about the big snow coming.

I felt compelled to “go rogue” and speak out against the NWS watch to dial back the hype and at least present a counter point of view. But despite these efforts and those of the broadcast media (who generally forecast lower amounts), the bottom line is that many people were either confused by the conflicting forecasts or misled into thinking a big storm was coming.

And we saw more salt on streets and sidewalks than snow.


Salt on the sidewalks of northwest D.C., but no snow Thursday night. (Ian Livingston)

My general view, given the NWS’ strong track record, is that this particular forecast was a fluke. But NWS might consider, in its post storm review, employing some procedures that will lead to a more judicious process for issuing watches.

I’m not sure it’s realistic to ask NWS to consult media forecasters before issuing watches (and/or warnings) - that could just slow the process down for a legitimate storm threat when time is of the essence. And I’m not arguing the NWS is incompetent and can’t make its own forecasts; its forecasters are excellent - this one case notwithstanding. But it should strive to work with media to provide a coordinated, consistent message for the public and decisionmakers in winter weather situations.

The communications for this particular storm were a colossal mess, could have been avoided, and let’s hope are not repeated .

By  |  12:12 PM ET, 01/18/2013

Categories:  Latest, Winter Storms, Government

 
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