Melissa Di Spigna NOAA/National Weather Service Ronkonkoma, NY
Joey Picca NOAA/National Weather Service Norman, OK
Forecasting East Coast winter storms comes with inherent uncertainties. Tight gradients in snowfall amounts across the storm due to track, mesoscale banding and precipitation-type transitions are common. When considering the dense population corridor extending from Washington D.C. to Boston, a change in the cyclone track of even 10-20 miles can substantially change the severity of impacts felt by millions of people.
The intense scrutiny that followed the January 2015 blizzard forecast for Philadelphia and New York City set forth an interesting national discussion on the need for not only an improvement of forecast accuracy, but also the effective communication of forecast uncertainty.
In parallel with meteorological information available at the time, the authors will present timelines from the perspective of local decision makers with regard to mass transit, road closures, schools and other entities in the New York City metropolitan area. In contrast, a 2013 blizzard will be shown to illustrate consequences of varying levels of 'most likely' scenario forecasts and their attendant uncertainty. As we prepare for potentially more frequent extreme weather, we need to examine how to convey our message in a way that reduces society's vulnerability to the impacts. However, the authors will demonstrate that, perhaps even more importantly, the range of forecast uncertainty has to be manageable for the communication of it to have the most value to decision makers and the public.