Partly to mostly clear. Areas of river valley and lake fog. Light winds becoming SW at 10-20 mph, with higher gusts, by morning on middle to upper elevation mountain ridges. Temperatures varying from 50s in cooler mountain valleys to the mid-upper 60s.
Monday Afternoon
Partly-mostly cloudy. A chance of showers-thunderstorms, then showers and thunderstorms becoming likely by late in the afternoon-early evening. More humid. Winds SW-WSW 10-20 mph, with higher gusts ( especially along mid-upper elevation mountain ridges ). Temperatures varying from upper 60s-lower 70s in upper elevations to the upper 70s to lower 80s ( warmer south into the Great Valley ).
Monday Night Into Tuesday Morning
Any evening showers ending. Turning chilly. Low clouds and dense fog at higher elevations above 2500-3000 feet. Winds becoming NNW-N at 5-10 mph, with higher gusts, on mid-upper elevation mountain ridges. Temps dropping into the 40s to lower-middle 50s ( warmer in lower elevation valleys of the Clinch, Powell, Holston river basins ).
Tuesday Afternoon
Becoming mostly sunny. Cool. Light WNW-NW winds. Temps varying from the 50s to lower 60s in upper elevations to the upper 60s to lower 70s.
Tuesday Night Into Wednesday Morning
Partly-mostly clear. Chilly. Winds WSW-WNW at mostly less than 10 mph on mid-upper elevation mountain ridges. Temperatures varying from mid-upper 30s in colder valleys to the mid-upper 40s. Areas of valley fog, especially along major rivers-lakes. Patchy frost possible in coldest valleys.
Numerous showers & thundershowers, some with possible hail due to cold air aloft, are being monitored for mid-late week amid chilly air associated with a slow moving upper-level low pressure.
Weather Discussion ( Autumn Arrives )
The big weather news this week will be the arrival of true autumn air, with chilly conditions expected to be felt across the mountains ( some will say cold given Summer 2016 ).
European 51-Member Ensemble MEAN 500 MB Height Anomalies
While low dewpoint air will pour into the mountains Tuesday, and linger into early Wednesday, it appears that a slow moving upper level low pressure will develop to dominate mid-late week.
European 51-Member Ensemble MEAN 850 MB Temps & Anomalies
This type of pattern would generate very chilly conditions, especially in upper elevations, with exact positioning and movement of the upper low helping to ultimately dictate day to day weather during September 28-October 1.
