Scientific Forecaster Discussion
000 FXUS64 KMRX 190711 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 311 AM EDT Thu Oct 19 2017 .SHORT TERM...(Today through Saturday night)... Tranquil weather will continue across the area for this period as a large high pressure ridge will maintain its position over the Southern Appalachian region. Some cirrus with a shortwave trough will cross the area today, but it should have little impact on the sensible weather. The warming trend of the past few days will continue today and tomorrow, with highs today in the mid 70s, then upper 70s on Friday and Saturday. Clouds will be increasing on Saturday and Saturday night as the ridge axis shifts toward the Atlantic coast and a trough deepens across the Plains. .LONG TERM...(Sunday through Wednesday)... Model forecasts for this period have some timing, positioning, and strength issues but it appears that we squeeze out one final day of basically dry weather on Sunday as an upper trough deepens into an upper low over the Lower Mississippi Valley later Sunday into Monday. Showers and some thunderstorms will start to build into the Southern Appalachian region during this period, and will become likely Monday into Monday night. The showers will taper off a bit behind the a cold front associated with the upper trough. However, more jet stream energy will be diving south out of Canada allowing for the amplification of a deepening long wave trough over the Eastern states. Therefore, a medium to high chance for showers will continue Tuesday into Wednesday as sufficient moisture and lift accompanies this slow moving trough. Very chilly air will build south into the forecast area at mid week. Temperatures will be about five to ten degrees below normal on Wednesday and there may even be a few snow flurries in the highest elevations along the North Carolina border Wednesday night. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 74 45 78 48 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 73 43 77 48 / 0 0 0 0 Oak Ridge, TN 73 44 78 48 / 0 0 0 0 Tri Cities Airport, TN 73 41 77 43 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None.