The last day of November brought a very familiar late fall/early winter weather pattern to the Tennessee Valley–very warm (but not very unstable) conditions with tremendous wind shear, abundant (occasionally flooding) rainfall, followed by sharply colder conditions with upstream reports of snow and sleet.
The earliest part of the day was spent watching radar for potential tornadoes. Everyone was aware of the devastation that struck central Mississippi, but conditions were not expected to be as unstable across north Alabama. The SPoRT ADAS improved the radar operators’ situational awareness–and thus the decision to issue (or not to issue) warnings–by helping identify the location of the warm front and most unstable air. Fortunately, the greatest impacts to the region involved heavy rainfall, and little wind damage was reported across the Huntsville CWA.
Later in the morning a new forecast challenge evolved: would any post-frontal precipitation fall in the form of sleet or snow? Here again the SPoRT ADAS assisted the forecast team. By using the ADAS temperature and dewpoint fields in concert with observations, forecast models and forecast sounding data, the forecast team decided to include only a slight chance of snow and sleet. (Fortunately, again, the Huntsville CWA dodged the most active weather and saw little if any wintry precipitation.)