ROANOKE, Va. – As Michael passed south of the area, the worst weather we felt came in the way of blinding rain and significant flooding. However, especially after the storm, the wind really started to pick up at times. Wind Advisories were in effect for the entire StormTeam 10 viewing area through Friday morning.
A large part of the wind gusts had to do with the fact that high pressure was moving in behind the departing Michael. Air naturally tries to move towards low pressure. The Coriolis force deflects that air to the right, so our wind came in out of the northwest. That northwest wind also accelerated down the mountains, making things breezy at times.
There was another element to this, though, that created a narrow strip of even gustier wind from Bath and Highland Counties, through Bedford County and into parts of Southside.
This element is called the "sting jet."
On opposite sides of the front that was pushing Michael out, you had a warm belt to the east and a cold belt to the west. Cold air naturally sinks, but you also had evaporation taking place.
Rain droplets higher up were falling into a drying air mass, and evaporation started happening. Evaporation causes the air to cool. By cooling a cool belt, the air can rush faster down to the surface.
Data from Danville and South Boston can not be found, since it went out around 4 p.m. Thursday. However, observed gusts from around the area ranged from 35-50 mph around the time that the sting jet was around.
In extreme cases, you can sometimes see a sting jet produce wind gusts of 100 mph or greater. Thankfully, that did not happen around our area Thursday night.