ALERT For Strong SSE-SSW Winds Developing Saturday Afternoon Into Saturday Night
A strong pressure gradient will develop generally strong winds across the mountain region during Saturday afternoon into Saturday night, with developing rain showers and the chance for thunderstorms.
Strongest general winds are expected in upper elevations at 30-50+ mph speeds, with locally higher gusts, and in mountain wave breaking zones where local gusts to hurricane force will be possible.
Previous Alerts
High Knob Massif Webcam_University Of Virginia’s College At Wise
Wintry conditions dominated the first 8 days of March, with 3-4″+ of snowfall observed from the elevation of the High Chaparral and Robinson Knob communities upward in elevation within the High Knob Massif (1.4″ Clintwood ). Still much more rain than snow, a trend that will continue.
ALERT For Hazardous Conditions Friday AM
A period of moderate to heavy snow will impact the mountain area Friday morning. Accumulations of 1″ to 3″ are expected at mid-upper elevations, with up to 1″ at lower elevations, prior to changing to mix-rain, within locations along and north of the High Knob Massif-Tennessee Valley Divide.
Most of the past four days have been below freezing (and remain below freezing at highest elevations), such that ground surfaces are cold.
Snow will be developing during the predawn-early morning before surfaces have a chance to warm. Caution is advised.
Weather Headlines ( March 4-11 )
High Knob Massif Webcam_University Of Virginia’s College At Wise
A gorgeous array of rime covers a huge area along the common borders of Wise-Scott and Lee-Harlan counties, with a little even decorating the Wise-Sandy Ridge plateaus.
A cold pattern is currently gripping the mountain landscape, with Monday featuring daytime temps in the 10s across upper elevations and the 20s in places at lower-middle elevations along and north of the High Knob Massif and Tennessee Valley Divide.
European 51-Member Ensemble Mean 500 MB Height Anomaly Forecast_Days 5-9
Looking ahead the pattern will be reverting back to what dominated most of February 2019.
This means more concerns for high water events are upcoming as a series of waves move across the Pacific Ocean and the continental USA.
Composite Climatology For 9 Different Flood Events_Mean 500 MB Height Anomalies
While a composite of 9 historic flood events reveals a somewhat sharper wave amplitude, and slight eastward displacement, it is otherwise strikingly similar to the February 2019 pattern.
The similarity of the February 2019 pattern and a composite of 9 past flood events is rather striking.
Composite Climatology For 9 Different Flood Events_Mean 850 MB Wind Vectors
A common denominator of the composite of past flood events is Gulf of Mexico, Atlantic and Pacific ocean moisture sources feeding heavy-excessive precipitation amounts.
This is a positive mountain torque pattern with inflow and orographics favoring locations along and west of the Eastern Continental Divide.
Composite Climatology For 9 Different Flood Events_Mean Sea Level Pressure
So, it really should not be surprising to see where the heaviest precipitation has fallen in this pattern given what past climatology illustrates.
NWS Precipitation Analysis and Doppler Estimated_Past 60-Days
It should also be no surprise, that real concern exists for the upcoming pattern if the first graphic in this section, and this 6-10 day graphic (below), verifies.
European 51-Member Ensemble Mean 500 MB Height Anomalies Forecast_Days 6-10
More severe storms and flooding will occur in such a pattern, so stay tuned for future updates by late this week into early next week.
