100220 Forecast

The 14th Annual High Knob Naturalist Rally will continue virtually through this week and next.

14th Annual High Knob Naturalist Rally Sponsored by The Clinch Coalition

High Knob Hellbender 10K Race

Fair Weather Cumulus_Day Before Race_2 October 2020

Weather conditions for the 7th Annual Hellbender 10K will be nearly ideal this year, with light southwest winds and seasonally chilly conditions under partly to mostly sunny skies (featuring fair weather cumulus).

Frosty cold sunrise conditions in the Norton Valley will warm quickly through mid-morning. Air temperatures in the 40s (4° to 9° Celsius) can be expected along the course that follows a 10:00 AM start time Saturday.

Expect air to dry with increasing elevation. A drop in relative humidity values will occur above the valley floor, toward the summit level of the massif, through mid-morning into mid-day Saturday.

Mountain Valley Frost

City of Norton Minimum Temperature For 2 October 2020

Areas of frost were featured in colder valleys Friday morning, such as in the Norton Valley which had temps analogous to the summit level of the High Knob Massif (the main difference being low-mid 30s accompanied wind chills in the 20s at the summit).

NOTE: Significant differences are typical on these mornings between the Norton Valley and adjacent Wise Plateau, with colder temperatures and enhanced frost on the floor of the Norton Valley (including the Big Laurel to Esserville and Ramsey to Tacoma corridors), and low spots within the plateau, often contrasting with milder, frost-free conditions in exposed locations of the Wise Plateau and higher places within the City of Norton.

Forecasters should not confuse Norton with Lonesome Pine Airport in Wise (especially for those following obs), as they are within two distinctly different topographic settings with significant weather contrasts on nights featuring radiational cooling and cold air drainage.

The Norton Valley is influenced by cold air drainage from both the High Knob Massif and northeastern end of the Black Mountains versus the Wise Plateau which features only localized drainage into lower sections, especially those once known as The Big Glades.

River Valley Fog_8:51 AM_2 October 2020

Latent heat of condensation associated with fog formation will help to prevent or minimize any frost formation along major river valleys and near the larger, lower-elevation lakes.

River valley fog will continue to be a nocturnal feature, as typical at this time of year, to contrast with below freezing conditions developing overnight into Saturday morning within the colder, high elevation valleys from the High Knob Massif to Burkes Garden.

Cooler-Drier Than Normal Short-Term

Near To Below Average Local Temperatures

Generally cooler and drier than average conditions will continue to dominate the short-term forecast period into next week, when a warming trend develops.

Drier Than Average Local Conditions

A drier pattern is very welcome in wake of wetness, with the past year featuring 100.29″ of total precipitation at Big Cherry Lake Dam in the High Knob Massif.

Big Cherry Dam Breaks 100.00″ During Past Year

Reference the above link for other totals observed during the water year from October 2019 to September 2020.