A very interesting occurrence happened on Monday morning of this week, a 27 degree temperature difference across the High Country. The facebook pages of NWS Blacksburg and L'Heureux's Weather were a buzz about the event.
Below is the GFS Sounding from L'Heureux with an explanation.
“I pulled up this mornings sounding and there is a lot to write about here. In the blue box is the dew point (green line) and in the pink box is the temperature (red line). The sloping black lines I have marked are the 0*C and 10*C temperature. Notice that Boone (near 910mb level, labeled) is at about 0*C while Grandfather Mountain (above 850mb level) is at 10*C. The relative humidity at the top of Grandfather was at 3.0% (middle of dry layer). Notice the dew point on top of Grandfather is below -35*C. That is an incredible inversion layer.— with Boone Elevation and Grandfather Mountain Elevation.”
Here's another graphic from the NWS Blacksburg facebook page. Graphic by Baker Perry, Assistant Professor of Geography at Appalachian State University. “Mountain Meteorology can have its extremes, as evidenced by the temperature and humidity observations across the High Country of North Carolina from Monday morning November 7th, 2011. Note the 27 degree temperature difference between Beech Mountain (5500 ft) and Bethel (2763 ft), and the extremely low humidity (2-3 %) at the mountain peaks versus the mountain valleys (near 100%). ”