Reference Early Spring 2021_High Knob Massif for an update on recent and Winter 2020-21 conditions.

ALERT For Elevated Stream Levels And Ponding Of Water In Flood-Prone Low-Lying Areas Into Early Friday

While locally strong-severe thunderstorms remain possible this afternoon, residents and travelers will need to closely monitor stream levels due to a general 2.00″ to 2.50″ of rain that has fallen on headwater creeks from the High Knob Massif into Black Mountain.

Any additional downpours, if prolonged or training, could quickly trigger flash flooding.

An influx of cold air tonight into early Friday will change rain to snow at upper elevations, with 1″ to 3″ possible (mainly above 3300-3500 feet).

A pocket of cold air associated with an upper-level low currently over western portions of Kentucky-Tennessee will support a transition to snow at high elevations into early Friday. Travel along routes 619, 238, 237, 704, 160 and others that run above 3300-3500 feet could become slushy overnight into early Friday morning.

Previous Discussion

Heavy rain with the potential for strong to severe thunderstorms is being monitored for Thursday (18 March 2021).

Conditions favorable for a major outbreak of severe thunderstorms are coming together over the Deep South and lower Mississippi River Valley. Strong-severe thunderstorms will move northeast into or toward the Appalachians Wednesday night into the early hours of Thursday.

An outbreak of severe thunderstorms, with tornadoes, across the Deep South on Wednesday will spread into the Appalachians on Thursday with a continued chance for strong to locally severe storms.

Strong to severe thunderstorms will be ongoing early Thursday from the main outbreak to the southwest, and will need to be closely tracked.

Additional development will be possible along the mountains into the afternoon.

Potential for heavy to locally excessive rainfall will occur and depend upon where bands of thunderstorms and downpours develop.

Stay tuned to NOAA Weather Radio and your favorite media sources for the possible issuance of watches and warnings.

Thunderstorms To Snow?

A rapid influx of cold air aloft and toward the surface will create a potential for rain to end as snow during the predawn-morning hours of Friday, especially at upper elevations where accumulation can not be ruled out above 3000 to 4000+ feet.