A mere dusting of two inches of fluffy snow Wednesday evening brought traffic to a standstill.  Some commuters were stuck in traffic for more than six hours, well past midnight, on major roads throughout the region.

Ineffective weather forecast communication and lack of preparation by road crews converged to cause the nightmare.

[An inch of snow, icy roads unleash 9 hours of traffic chaos across D.C. region]

The forecasts for the storm weren’t, by themselves, horrible.  Most outlets predicted a dusting to an inch for the evening, just a little less than what actually fell, and also communicated that roads would be slick because it has been so cold recently.


Snowfall totals Jan. 20, 2016. (NWS)

But the forecast communication for the storm was overshadowed by efforts to prepare the region for the blizzard forecast for Friday and Saturday.  Media coverage, somewhat understandably, focused on the bigger-ticket item.


Outbound on 14th Street bridge, 7:30 p.m. Jan. 20, 2016. (Va. commuter)

We are not blameless at the Capital Weather Gang.  Yes, we posted the winter weather advisory on our blog and social media platforms and indicated on several occasions that any snow that might fall would stick.  But as a whole, we underestimated and downplayed the event.  “Some areas may not see much snow, if any, while others may see a dusting to – at the very most – a quick inch,” we wrote at 11:30 a.m. “Use caution if it’s snowing during your commute, or consider delaying until the heaviest snow passes.”

As we were slammed with blizzard forecast coverage, we did not do a dedicated post focusing on the threat which we would have done under normal circumstances. Our social media messaging coverage of the event was spotty and uneven. On the one hand, we told people that the snow could be a commuting issue, but just as it was beginning, we played it down, calling for flurries.

In fairness to ourselves, I am not aware of other media outlets that accurately or convincingly conveyed the threat. The National Weather Service made a solid call by issuing an advisory and led some social media outreach, but it did not release a special weather statement or coordinate with media in an effort to advertise the threat. In other words, this was a weather-enterprise-wide communication failure.


Traffic is bumper to bumper and mostly at a standstill on the outer loop of the I-495 Capital Beltway after snow fell Jan. 20 in National Harbor, Md. As Washington prepared for a weekend snowstorm, forecast to reach blizzard conditions, a small clipper system pushed through the region Wednesday night, causing massive delays and issues on the roads. (Alex Brandon/AP)

But it’s difficult for me to be too hard on forecasters, overall. It was tricky little event that, as it approached, looked like it was dying but then suddenly flared up. One of our go-to short-term models, the HRRR,  often very helpful in these kinds of situations, performed dismally, simulating essentially no snow in the hours leading up to and even during the event.

The snow turned into such a problem because it immediately stuck on the cold pavement and then would melt and refreeze as cars passed over it.  Critically, many roads were untreated, so the ice persisted.

Jim Lee, the meteorologist-in-charge at the National Weather Service office serving the D.C. area, said local transportation departments were briefed prior to the event. “Our standard procedure is to call MDSHA, DCDOT and VDOT after we issue the advisory,” he said. “That was accomplished yesterday.”

So it is not clear why crews weren’t better prepared.  Nevertheless, I can’t totally blame them for not doing a wholesale deployment of chemicals when the forecast message wasn’t necessarily urgent and crystal clear.

After the so-called Commutageddon debacle of Jan. 26, 2011, when thousands of cars in the D.C. area were stranded overnight in a rush-hour snowstorm, I hoped it would never happen again.  But that was probably naive.  As good as our forecasts have gotten and even as we learn from past experiences, the state of forecasting remains imperfect enough and our infrastructure so vulnerable to these kinds of events that they are very hard to avoid once in a great while.

[Commutageddon: Could we all have done more?]

Still, that doesn’t mean we shouldn’t try to learn from them or respond defensively.  Both forecasters and road crews didn’t exhibit the situational awareness to have the city ready for last night’s event. We must take away from this that whenever there is even the slightest threat of snow or ice during commuting times when road surfaces are cold, alarms need to be sounded and action decisively taken.

Photos