CHARLOTTE, NC (WBTV) - The attached picture shows our latest snow accumulation forecast map for Wednesday night's snow storm. I was almost tempted to just slap down 3" - 6" for the entire area with the exception of the SC counties as it is nearly impossible to try and extract more detail from data that is still all over the place right now. Warm air to our south does appear to be close enough where it will tamp down accumulations quickly as you head south into SC.
For those of you wondering why forecasting snow accumulations is so tricky, it has to with the tiny differences in our expectations of the amount of liquid content (i.e. rain if it was warm) that will fall as actual snow. In general just .1" of liquid precipitation equates to at least an inch of snow. So if we misjudge the water content by just 1/4" (hold your fingers 1/4" apart), that can make a difference of 3" of snow or more!! If I miss a rain forecast by 1/4", you'd never notice.
That's what I love about this challenge, but it can also make us look silly, especially to those who don't understand we have no margin of error in these forecasts.