Cold-air Damming Event East of Appalachians

The new color-enhanced satellite layer in the ForeFlight Mobile app typically provides an excellent representation of the overall cloud cover.  This morning, however, it wasn’t telling the whole story as an early December cold-air damming event took control of the airspace east of the Appalachian Mountains. In these events, cool, dense air gets wedged up against the mountains as radiational cooling in the overnight hours allows the clouds to build down to the surface to produce today’s nasty ground fog event.


Most airports east of the mountains all the way to the shore were reporting very low IFR conditions as seen by the magenta flight category markers above. Most airports were reporting indefinite ceilings at or below 200 feet with visibilities less than 1/2SM as shown below for the Charlotte Douglas Airport.

KCLT 031327Z 20003KT 1/4SM R18C/1800V2400FT -DZ FG VV002 07/06 A3030 
     RMK AO2 TWR VIS 1/2 P0000

The place to be this morning was western North Carolina near Asheville – one of the few green markers on the image above. This is one of those times where being high in the mountains is actually a distinct advantage. Asheville escaped the gloomy conditions this morning and had some rather nice weather with excellent visibility and a comfortably high overcast ceiling.

KAVL 031354Z 17005KT 10SM SCT065 OVC085 12/09 A3026 
     RMK AO2 RAB33E45 SLP242 P0000 T01170094

Tis the season for low IFR … get your ForeFlight on and fly safe!