The surprise East Coast snow of 2000

The timing was almost perverse. On January 18,2000, the US National Weather Service announced that its latest supercomputer for weather and climate models was officially online. Reaching five times the speed of its predecessor, increases in forecast accuracy were all but assured. Less than a week later, a snowstorm took shape over the eastern US in a far from straightforward fashion.The NWS's flagship Eta model kept the heaviest snow and rain just offshore, to the east of Washington DC, and other big coastal cities. Since this model often brought things too far west, forecasters downplayed the storm for the public – until the model changed its tune on the afternoon of Monday, January 23. The switch was too late to make the early-evening newscasts, but the late-night news spread the word that snow was on the way. No matter: the 30cm/12in that fell by morning threw the nation's capital into a frenzy. The drama was even more pitched in Raleigh, North Carolina. A day after mere flurries had been forecast, the city got some 51 cm/20in of snow, more than had ever fallen in Raleigh over an entire month. A glimmer of light surfaced long after the snow had melted, however. Scientists testing a research model with similar resolution to the new NWS flagship model found that it might have been able to accurately predict a storm like this one, given enough good-quality starting data.