A pocket of cold air aloft will increase the possibility of mid-late afternoon & evening showers during Sunday. Local thunder and small hail will be possible with the most well developed activity due to steep lapse rates ( 60-70 degree differences between the surface and 18,000 feet in the atmosphere ).
Overnight Into Sunday Morning
Mostly cloudy. Chance of showers. NW winds 5-15 mph, with higher gusts, along middle elevation mountain ridges and plateaus below 2700 feet. NW-N winds 5-20 mph, with higher gusts, on mountain ridges above 2700 feet. Temps varying in the 40s to lower-middle 50s ( coolest at highest elevations ). Wind chills in the upper 30s to lower 40s in gusts at highest elevations. Dense fog at elevations above 2700-3300 feet.
Partly to mostly cloudy. Chance of showers, especially by mid-late afternoon. Thunder & localized small hail possible. WNW-NNW winds 5-15 mph, with higher gusts ( especially along mountain ridges-plateaus ). Temperatures varying from 50s to around 60 degrees in upper elevations to the middle 60s to lower 70s.
Sunday Night Into Monday Morning
Chance of evening showers. Thunder & localized small hail possible. Becoming partly to mostly clear overnight. Areas of fog. NNW-NNE winds 5-15 mph on mid-upper elevation mountain ridges & plateaus. Temperatures in the 40s to around 50 degrees.
Partly to mostly sunny. Winds N to NE winds 5-10 mph. Temperatures varying from 50s in upper elevations to the middle 60s to around 70 degrees.
Monday Night Into Tuesday Morning
Mostly clear. Light winds. Seasonally cool with temps in the 40s to lower-middle 50s ( coolest in mountain valleys with cold air drainage ).
A warmer pattern featuring hit-miss showers and thunderstorms is expected during mid-late week. Locally heavy rainfall will be possible with some of the thunderstorms.
Weather Discussion ( May 21-24 )
A continuation of seasonally cool, damp conditions have been observed into this May 21-22 weekend, with limited sunshine across the mountain landscape.
*A general 0.50″ to 1.00″ of rain Friday Night, in counties along the Virginia-Kentucky border, being limited by vigorous Deep South convection.
Saturday PM temperatures varied in the 50s ( above 3000 feet ) and 60s, across lower-middle elevations ( 64 degrees at Nora 4 SSE and 69 degrees at Clintwood 1 W ), amid limited sunshine and hit-miss showers featuring a few brief downpours.
Conditions late Saturday evening into the start of this Sunday are coolest in upper elevations where breezy to gusty NW-N winds are creating wind chills in the low-mid 40s.
While the weather focus will be shifting toward a warmer and more summer-like pattern into next week, there will be one more day ( Sunday ) when a pocket of cold air aloft over the mountains will steepen lapse rates ( the temperature drop with increasing height ) enough to trigger instability showers into mid-late afternoon and the early evening.
A few of the more vigorous showers will have the potential for localized small hail and thunder due to this unseasonably cold air aloft ( -4 degrees Fahrenheit below zero at 18,000 feet ).
The beauty of late Spring will be fading into early Summer soon, with conditions trending that way during this new work week toward the Memorial Day Holiday.
The transition from this current cooler than average regime to one more like summer is shown well by the 51-Member European Ensemble group.
Temperatures will be going from below average to above average heading into late week and the Memorial Day Holiday.
Hit-miss showers & thunderstorms, mainly in the afternoon-evening hours, will become part of this pattern as main upper ridging develops over New England.