ALERT For Ponding Of Water Along Roadways And For Swift Water On Creeks Draining The High Country Of The High Knob Massif Into Monday Night
A general 2.50″ to 3.00″+ of rain has fallen from the City of Norton across the High Knob Massif, as well as into adjacent locations in the Clinch & Powell river valleys.
A Blast Of Cold Air Will Be Felt Tuesday Into Thursday AM With The Coldest Temperatures Of This Autumn At Highest Elevations ( Especially ).
Low wind chill values for this time of year are expected at upper elevations in the high country during Tuesday into Wednesday. Coldest valley temperatures may occur by Thursday AM, but will depend upon the timing of the next digging trough. Stay tuned.
Overnight Into Monday Morning
Increasing clouds. Chance of a shower by sunrise. Windy across middle-upper elevation mountain ridges-plateaus. SSE to S winds 10-20 mph, with higher gusts, along ridges-plateaus below 2700 feet. SSE to S winds 15-25 mph, with 30-50+ mph gusts, along mountain ridges above 2700 feet. Mild with temperatures widespread in the 50s to low 60s.
Monday Morning Through Monday Afternoon
Rain developing with a chance of thunderstorms. Downpours likely. Locally heavy rainfall totals, especially within upslope locations across the High Knob Massif and Tennessee Valley Divide. Windy. SSE winds shifting SW at 10-20 mph, with higher gusts, below 2700 feet. SSE to SW winds 20-30 mph, with higher gusts, above 2700 feet. Low cloud bases with dense fog across upper elevations. Temps dropping into the 50s lower-middle elevations, and into the 40s upper elevations, by mid-late afternoon.
Monday Night Into Tuesday Morning
Rain tapering to light rain. Partial clearing possible by morning. Chilly. SSW to SW winds at 10-20 mph, with higher gusts, along mid-upper elevation mountain ridges. Temperatures varying from the mid 30s to lower 40s. Wind chill factors in the 20s highest elevations.
Tuesday Afternoon
Partly to mostly cloudy. Chance of rain showers. Chilly. SW-WSW winds 5-15 mph, with higher gusts. Temperatures varying from the low-mid 40s to the low-mid 50s ( coldest in upper elevations ), dropping by late afternoon. Wind chills in the 30s & 40s, except locally colder on highest peaks.
Tuesday Night Into Wednesday Morning
Partly cloudy. Cold. SW-W winds 5-10 mph, with higher gusts along mid-upper elevation mountain ridges. Temps varying from the mid-upper 20s to the lower-middle 30s, coldest in the upper elevations. Wind chills in the 20s and 30s, except dropping into the 10s at high elevations in the High Knob high country above 3300-3500 feet.
With blocking at high latitudes another deep upper air trough is expected to dig into the region by late week into this weekend of October 27-30. The will be monitored for the potential of the first accumulating snow in the mountains. Stay tuned for updates and changes that may diminish or enhance this potential.
Weather Discussion ( Colder Pattern )
A trend toward a much colder weather pattern is taking shape for the coming week. This transition will feature strong winds into Monday, with general strong speeds at upper elevations and local mountain wave winds in the favored breaking zones lee of the larger mountains.
Big Cherry Wetland Valley – October 21, 2017
An average nightly MIN of 28.2 degrees was recorded at Big Cherry Valley 4 in the High Knob Massif during October 17-21, with a total of 39.2 hours now being observed below freezing in October. Many trees on, and along, the high valley floor are now bare of leaves.
The potential for heavy rainfall, with at least a period featuring torrential downpours, along and ahead of a strong cold frontal zone of convergence, will be possible everywhere into mid-day to early afternoon Monday.
HRRR Model Future Doppler Forecast At 11:00 AM Monday – October 23, 2017
The heaviest rainfall, and highest totals in general, are expected in favored upslope zones where strong winds will help enhance orographics. This includes the eastern slopes of the Blue Ridge, as well as the High Knob Massif – Black Mountain corridor within the Cumberland Mountains.
HRRR Model Future Doppler Forecast At 1:00 PM Monday – October 23, 2017
Chilly air pours into the mountain region into Tuesday and Wednesday, with rather significant wind chills for this time of year within the high country of the High Knob Massif on gusty SSW-WSW winds.
European 51-Member Ensemble Mean 500 MB Height Anomalies: Days 1-5
This will mark the beginning of a much different pattern than experienced during most of October 2017, with much colder conditions ( in the mean ) expected throughout the next 10 days to close October and open November 2017.
European 51-Member Ensemble Mean 500 MB Height Anomalies: Days 6-10
While temperatures trend below average in the next few days, it is the extended 6-10 day period that has a notable potential to turn down-right wintry in the eastern USA.
European 51-Member Ensemble Mean 850 MB Temp Anomalies: Days 1-5
Could this include the first accumulating snow of the season, at least in upper elevations ( if not lower ) on upsloping NW winds as a coastal storm develops?
European 51-Member Ensemble Mean 850 MB Temp Anomalies: Days 6-10
It remains too early to know for certain; however, the trend and upper air pattern is supportive. Check back later as the details of this evolving pattern become more clear.
