Mountain Area Forecast ( July 21-23 )
The hottest temperatures of this year will be possible in most places during Thursday-Friday ( July 21-22 ) before increasing humidity-clouds return a chance for showers and downpours in thunderstorms this weekend through next week ( especially in the mountains ). Use common sense ( slow down, take it easier and never leave pets or children in a vehicle – check on the elderly and those without air conditioning ).
Any thunderstorm developing this weekend into next week could be strong to locally severe with booming thunder and dangerous lightning, gusty winds, and gully washing rains.
Overnight Into Thursday Morning
Mostly clear. Areas of valley fog. Light N winds shifting ENE to ESE at generally less than 10 mph along mid-upper elevation mountain ridges-plateaus. Temperatures from mid-upper 50s to the mid-upper 60s ( except lower 50s in upper elevation valleys above 2700-3000 feet within the High Knob Massif ).
Mostly sunny. Hot. Light NE winds. Temperatures varying from mid-upper 70s at highest elevations to the mid-upper 80s in middle-low elevations north of the High Knob Massif and Tennessee Valley Divide. MAXS 90 to 95 degrees lee of the High Knob Massif into the Great Valley.
Thursday Night Into Friday Morning
Mostly clear. Areas of valley fog. Light winds, except breezy-gusty along high mountain ridges. Temps varying from the mid-upper 50s to mid-upper 60s, except 50-55 degrees in higher valleys above 2400-3000 feet.
Partly cloudy. Hot. Chance of hit-miss showers or thunderstorms. Increasing humidity-haze. Light NW-NNW winds. Temperatures varying from mid-upper 70s at the highest elevations to mid-upper 80s ( hotter south and southwest toward Jonesville and the Tri-Cities ).
Friday Night Into Saturday Morning
Partly-mostly cloudy. Chance of a shower or thunderstorm. Haze with areas of valley fog. Light winds. Temperatures varying from upper 50s to lower 60s in cooler valleys to the mid 60s to low 70s ( mildest exposed mid elevation ridges ).
Partly cloudy. Continued hot. A chance of hit-miss showers and downpours in booming thunderstorms. Generally light winds outside of any storms. Temperatures varying from mid-upper 70s in upper elevations to the middle to upper 80s ( hotter toward Jonesville and the Tri-Cities ).
A steamy air mass will will support a daily chance for showers and downpours in thunderstorms from Sunday through next week and the final days of this month ( July 24-31 ).
Weather Discussion ( July 19-24 )
Thursday Evening Update
Drier air allowed for a relatively large day-night temp spread during Thursday, with AM MINS in the 50s within mountain valleys and afternoon MAXS in the 80s.
The official temperatures for Clintwood featured a 30 degree temp spread between 57 degrees Thursday AM and 87 degrees in the PM.
I took the above photograph in short-sleeves, but actually felt a little cool by the time I left with a near steady north breeze and temperatures around 70 degrees.
Due to moisture evaporation from the ground & vegetation it is difficult to officially break 90 degrees across most of Wise and Dickenson counties, especially along and north of the High Knob Massif and near Cumberland Gap NHP in Lee County where wetter summer conditions have prevailed.
A couple more days will have a chance to make a run for 90 in the lower-middle elevations, but eventually clouds and an increase in showers-storms will take its toll and hold temperatures back ( as humidity rises to make it steamy ).
Conditions are different to the south, into the Great Valley, where much drier ground has allowed the Tri-Cities to rack up the 90+ degree days during Summer 2016.
No surprise given 19.62″ of total precipitation this year in the Tri-Cities, with 3.71″ during June 1 to July 21, versus more than 31.00″ in the City of Norton ( around 10.00″ during June 1-July 21 ) and around 40.00″ in upper elevations of the High Knob Massif.