The Model Ingest System uses Data from "Official Weather Station's" (Airports, NWS Coop Station's etc) and NWS Certified Observers. The NWS also uses Cocorahs Data. I don't know if it's implemented directly into the System or not. Should be.
Recording and Incorporating all this Data is how the Model's should get better over Time.
The Model's also incorporate Weather Baloon, Atmospheric Sensor Data etc..
There is downsloping that occurs, particularly from off the Mountains along the KY Border. Model's do overemphasize that sometimes. It doesn't affect exteme Northern Lee much as it sits on a Plateau that runs on across the Norton and Wise area in Wise County.
The main thing that is affecting the Model's irt Lee County is the Official Pennington gap Station. It is the only Official NWS Station in the County. It is at the Sewer Plant along the Powell River, Operated by Town Employees.
I have checked out the Site personally and found notable flaws that affect accuracy greatly. It is not manned 24/7. Just Day Shift. I'll hopefully get over there before long and get a Couple of Pics and post.