Now Is The Time - NAM 24-36 Hrs Out

It's a good time for me to think about snow amounts for portions of east/se Kentucky. The NAM has been very consistent over the past several runs about a possible snow event.

I want to show you a 850mb map from the NAM for tomorrow (Wednesday morning).

Feel free to enlarge the map above by clicking on it. Take note where the zero line is (the solid dark line). For me, it's not so much that the zero line says snow at the surface. I like to see those values around -4 or -6 to see mostly snow at the surface.

Depending on when the precipitation starts, it appears from this run that temperatures above will be warm enough to support mainly rain or a rain/snow mix for the east/southeast during the daylight hours.

However, note what happens by nightfall...

This time, I would like you to click on the map above. Note that the zero line is far east of the region by Wednesday evening. More importantly, notice that temperatures at the 850 mb level will be cold enough to support snow (at least -4). Also, examine that humidity levels will be quite high as indicated by the green shading thus supporting that flakes should still be flying by then in far east and southeast Kentucky.

The latest NAM model run (12z) shows precip breaking out during the morning hours tomorrow. Should be all liquid then. As the day progresses, expect rain transitioning to a mix, and then by nightfall, should become all snow with up to a couple of inches for those areas I highlighted in an earlier post, from Pineville to Pikeville. Most accumulations should be confined to grassy surfaces. However, some slick spots could develop as wet roadways could freeze during the overnight. May even be slushy accumulations in some of the higher elevations on the roadways.

Note the 2 meter temperature profile for overnight late Wednesday/after midnight Thursday, still shows temps near or above freezing. Most precip should be winding down by then.

Therefore, I still think WWAdvisory could go up during the evening and overnight hours for those locations mentioned above as temps could fall below freezing the rest of the night. Really depends on the temperature of the pavement, as well.

Summary:

From Pineville to Pikeville, 1-2", mainly grassy surfaces; up to 3 or 4" in highest elevations of far southeast Kentucky.

Isolated slick spots after dark.

MS