ALERT For The Development Of Accumulating Snow Thursday

A wave of low pressure moving along a stalled boundary in the Deep South will spread snow across the Mountain Empire Thursday. This is expected to be a fast hitting and short-lived event, with the bulk of snow falling between 8:00 AM and 4:00 PM. Some upslope snow showers will continue into evening.

Update At 1:30 AM_Thursday_20 February 2020

ALERT For Hazardous Travel Conditions Developing Thursday Morning Into Early Afternoon

Cold temperatures, with widespread 20s in valley locations along and north of the High Knob Massif, will set the stage for hazardous conditions Thursday as a combination of initial evaporative cooling and snowfall rates work to cover roadways.

Snowfall Forecast

1″ to 3″ along and southeast of Pine Mountain across southwestern Virginia and extreme southeastern Kentucky

3″ to 5″ at higher elevations of the High Knob Massif and Black Mountains, with locally higher amounts possible

Target snowfall: 2.5″ at 2500 feet (+/-) 1.0″ error potential, suggesting 1.5″ to 3.5″ of snow will be possible in the Norton-Wise area.

The error potential has been reduced by increasing confidence in a developing snowband impacting all locations along and southeast of Pine Mountain on upsloping, northerly low-level air flow.

Cold air will be interacting with moisture along the northwestern and northern side of this snow band to create lower snow density and higher snow-to-water ratios than farther south.

A sharp cut-off is expected to the northwest and southeast of a band of snow that will develop Thursday over the southern Appalachians and Tennessee Valley. Heaviest snow amounts are currently expected at highest elevations along the Eastern Continental Divide (from Roan Mountain to the crestline of the Great Smokies).

Weather Headlines: 17 February 2020

*Strong SSE-SW winds develop tonight into Tuesday at middle to upper elevations (especially). Wind gusts to over 40 mph will be possible at highest elevations.

*Rain overspreads the mountain area Tuesday. Moderate to locally heavy rainfall will be possible through Tuesday night, especially from favored upslope locations in the High Knob Massif-Black Mountain corridor southward.

*Rain may end as snow during the predawn-morning hours of Wednesday, with any accumulation likely restricted to elevations above 3000-3500 feet.

*A secondary wave of low pressure moving along a stalling boundary to the south will need to be closely monitored for potential development of a heavy, wet band of snow Thursday, with positioning of this band remaining uncertain. Stay tuned for updates.

The position and intensity of a potential snow band remains to be worked out, but many models (especially when including ensemble members) are beginning to see a potential that has now been shown on and off in the modeling for about a week.

Upcoming Pattern

Snow can not fall without cold temperatures, so at the least a colder regime is shown to rebuild in the mean during the short-term (following current warming).

Following a period of warming next week, the European ensemble mean is forecasting colder air to return in the first week of March and the beginning of Meteorological Spring. A trend to follow as the polar vortex remains at strong to near record-strong levels (one of the drivers of this mild winter of 2019-20 in the eastern USA).