100717 Forecast

Mountain Area Forecast ( October 7-9 )

ALERT For Strong Winds & Heavy Rainfall Developing Sunday Into Monday Morning With Remnants of Nate  

Strong Rises On Mountain Streams Will Become Possible By Sunday Night Into Monday Morning

Remnants of Hurricane Nate will begin impacting the mountain region Saturday Night into Sunday Morning with developing rain.  Rainfall will become heavy during Sunday into Monday Morning, especially along windward slopes & crestlines of major orographic features like the High Knob Massif.

Reference My October 7-8 Race Forecast For More Detailed Information On The High Knob Hellbender 10K and The Cloudsplitter 100 Races.

Overnight Into Saturday Morning

Partly-mostly clear ( some high clouds ).  Becoming gusty higher elevations.  SSE-SSW winds increasing to 10-20 mph, with higher gusts, on middle to upper elevation mountain ridges.  Temps varying from 40s in cooler mountain valleys ( sheltered from winds ) to middle-upper 50s to around 60 degrees on exposed mountain ridges and plateaus.

Saturday Afternoon

Becoming partly to mostly cloudy & more humid.  Winds SSE-SSW at 10-20 mph, with higher gusts.  Temperatures varying from upper 60s to lower 70s ( 18 to 22 Celsius ) in upper elevations, above 3000 feet, to middle-upper 70s ( 24-26 Celsius ) at elevations below 3000 feet.  Warmest at low elevations in the Hanging Rock Recreation Area where temperatures could rise above 80 degrees ( 27 Celsius ).

Saturday Night Into Sunday Morning

Becoming cloudy with light rain developing overnight into morning.  Cloud bases lowering to near or below the summit level of the High Knob Massif.  SSE-S winds 5-15 mph below 2700 feet.  Winds S-SW 10-25 mph, with higher gusts, above 2700 feet ( especially on mountain ridges ).  Temperatures falling into the 60s ( 16-18 Celsius ).

Sunday Morning Through The Afternoon

Increasing rain, with a chance for thunderstorms.  Locally heavy rainfall likely, especially along windward slopes and crestlines of the High Knob Massif.  Lesser rain amounts in downslope locales in central-northern Wise and Dickenson-Buchanan counties.

Winds SE-SSE at 10-25 mph, with higher gusts in upper elevations ( lighter winds at lower elevations in hollows-valleys ).  Temps near steady in low-mid 60s ( 16-18 Celsius ) at high elevations and in the upper 60s to middle 70s ( 20-22 Celsius ) at lower elevations ( below 2000 feet ).

Sunday Night Into Monday Morning

Rain becoming heavy.  A chance of thunderstorms.  Windy.  Dense fog ( orographic clouds ) across upper elevations in the High Knob Massif.  SE-S winds 15-25 mph, with higher gusts below 2700 feet.  SSE to SSW winds 25-35 mph, with gusts over 50 mph, at elevations above 2700 feet.  Temps widespread in the 60s ( low-mid 60s in upper elevations ).


Weather Discussion ( Nate & Races )

The recent streak of dry conditions will be ending this weekend, perhaps in a big way for some locations.  The timing will favor the High Knob Hellbender 10K Race and the first day of the Cloudsplitter 100 races; however, the second day of the Cloudspitter will be a different story featuring deteriorating conditions.

Reference my October 7-8 Race Forecast for details.

Autumn Beauty In Upper Elevations of High Knob Massif – October 5, 2017

Increasing wind and rain with Nate will not greatly impact trees at the summit level, where many trees are now bare around High Knob Lookout ( for example ), but color that is now approaching peak in other places of the high country could be hurt ( dulled and many downed ) by this system.

Autumn Reflections on Upper Norton Reservoir – October 5, 2017

As of the early overnight period of Saturday, Nate is under-going expansion and increasing organization.  Meanwhile, a cold frontal zone to the west has triggered a squall line to form from Texas across Oklahoma into Kansas.

NASA Infrared GOES-16 Image At 1:07 AM Saturday – October 7, 2017

Local conditions are already beginning to change, with a notable increase in both wind speeds and moisture levels across high elevations to strengthen a nocturnal temp inversion ( with cooler valleys & milder mountain ridges ).

Black Mountain Mesonet at 1:40 AM Saturday – October 7, 2017
An increase in wind speeds and rise in dewpoints have occurred at highest elevations between 9:40 PM Friday and 1:40 AM Saturday.
Black Mountain Mesonet At 9:40 PM Friday – October 6, 2017

This will set the stage for a more humid, mild Saturday with nocturnal mountain valley inversions mixing out following sunrise.  If the above trend continues, then some low clouds could begin developing above the mountain summits prior to Saturday afternoon ( when my forecast is calling for the conditions to become partly-mostly cloudy ).

Nate Becomes A Hurricane As of The 2 AM Advisory Saturday – October 7, 2017

Since Nate has now become a hurricane ( as of 2:00 AM ) the next 12-18 hours will be critical as to how strong he can get before landfall.  A stronger Nate = a likely stronger system post-landfall which will be important to impacts across the southern-central Appalachians.  Stay tuned for updates.