Numerous storms with accumulating snow, sleet and freezing rain, affected the Mid Atlantic U.S during the winter of 2000-2001, providing many challenges to forecasters in the region. Defining areas where accumulating snow was expected, and determining snow amounts proved to be a very difficult task.

On 2 December 2000 and 29 December 2000, significant snow (>5 inches) was forecasted for the Mid Atlantic U.S. However, the snow occurred >100 km east of where it was expected.

The positions and characteristics of upper-level (600-200 hPa) ridges, troughs, and jet streaks, caused an eastward shift in low-level (surface to 700 hPa) temperature advection, moisture advection, and upward vertical motion. Careful analysis of satellite data, upper air data, thermodynamic profiles, surface observations, radar data, and trends observed from these data sources, would have provided critical information for improving the forecast. A significant eastward adjustment (>100 Km) to areas of forecasted snowfall was possible, at least 12 hours in advance of the predicted onset.