Advisory up for southeast Tennessee, including Chattanooga.
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Morristown TN 1003 PM EST Fri Feb 7 2020 .
DISCUSSION... A lot to talk about this evening. The cold air
advection aloft that has kept the
scattered snow showers and flurries going across southwest Virginia and northeast Tennessee is diminishing. Another dusting (1/2 inch) of snow is still possible especially across the higher elevations. Cold air Strato-
cu is also slowly dissipating. Overall, low temperatures look good and made only minor adjustments. Biggest question is next system over the middle Mississippi valley. This wave and associated upper
jet across the central Gulf coast states will increase the
dynamics and isentropic forcing across northern Alabama by 09Z, then move east northeast into the southern Plateau and southeast Tennessee around daybreak. Model cross-sections and soundings show a couple hours of strong forcing in the
dendritic snow growth zone so a period of big snowflakes anticipated. Looking at the latest
ensemble snow plumes for Chattanooga shows a
mean close to 1 inch now so confidence of advisory level snowfall is greater now. Also, HREF precipitation type shows mainly snow for the southern Plateau and southeast Tennessee. Still expect most of the accumulations to be on grassy and elevated surface but the higher terrain could experience some travel issues. The greatest accumulations at CHA will be between 12-16Z. Have issued the
Winter Weather Advisory and updated the HWO.
