Scientific Forecaster Discussion
000 FXUS64 KMRX 201928 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 328 PM EDT Sun Aug 20 2017 .SHORT TERM...(Tonight and Monday)...Skies are mostly sunny and very warm to hot at mid afternoon with temperatures in the upper 80s to lower 90s. Heat index values are in the lower to mid 90s this afternoon. High pressure ridge has strengthened over the forecast area since Saturday and heights may build even more Monday. Cloud cover is limited to some scattered cu over the plateau and higher eastern Tennessee and southwest Virginia mountains. No precipitation is showing up on area radars too. Pattern looks similar Monday but a slight increase in moisture from east of the mountains will bring a small chance for showers and storms to higher elevations of Clay County NC and extreme northeast Tennessee mountains late afternoon to around sunset. This should not affect Eclipse viewing during the early to mid afternoon. The main concern is the warm temperatures and high UV index before and after the eclipse for people spending the day outdoors. Not much relief from winds which will be light south to southwest. Lows tonight should be a couple degrees warmer than Sundays...mid 60s north and northeast to lower 70s around Chattanooga. .LONG TERM...(Monday night through Sunday)...This part of the forecast remains basically unchanged with the main event being a high likelihood of frontal convection primarily Tuesday night into Wednesday with a gradual drop in probability Wednesday night as the cold front slips south and east onto the Piedmont. Cooler and drier air builds in for much of the remainder of the extended forecast. However, had to keep a little bit of an orographic pop going for the higher terrain features on Saturday and Sunday with a weak cyclonic flow developing aloft and a hint of an inverted trough forming at the surface. It still appears that there will be a nice drop in temperatures behind the cold front with maxes a good five to ten degrees cooler through the end of the work week and only a slight warming trend expected over the weekend. $$ && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 72 92 74 91 / 0 10 0 20 Knoxville McGhee Tyson Airport, TN 69 89 72 90 / 0 10 0 10 Oak Ridge, TN 70 91 72 90 / 0 10 0 20 Tri Cities Airport, TN 65 89 68 88 / 10 10 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None.