With the above average temperatures the 2011-2012 winter season has been associated with, its been difficult to remember that it actually is winter. Even with temperatures currently above average in the mid 50’s, the first major winter storm looks to affect Kentucky starting early Sunday with snow totals over 5″ possible in the higher elevations of eastern Kentucky. While models still differ a bit as far as totals go, there is little disagreement that snow will with be the main form of precipitation in the early hours of Sunday morning throughout the rest of the day in Warren County.
The following graphic courtesy NWS Louisville depicts estimated snow totals with the storm system:
Although I do mostly agree with these snow totals, there is certainly an elephant in the room. NAM depicts an area of strong vertical velocity over the Bowling Green region, and if this feature does verify, we may be in the higher end of expected snow totals (closer to 3″) opposed to the likely 1″ prediction other models are showing.
The following graphic shows the aforementioned vertical velocity feature:
Not only that, but temperatures have been above average for a few days (highs around 53°F since February 15th). This will make for a warm surface, so what will probably be the main factor in snow accumulation in Warren Co. will be can the snow fall rate overcome the rate at which snow will be melting. If snow can fall fast enough to cool down the surface temperature sufficiently, we will certainly see more accumulations.
This is certainly a tricky forecast, so ultimately only time will tell. Nearly 12 hours before the event will unfold.
Update: 18Z NAM model run depicting the area of enhanced vertical velocity to the south and east of Warren County, so forecast confidence leaning more toward < 2″.