My Rough Thoughts About Accumulations

Good Afternoon

Models are starting to come into better agreement and im going to go ahead with a forecast strictly for east TN based mainly off the GFS ensembles and my model of choice is the GFS op since it has been more consistent than the others. It did stray away from the closed low over the TN valley for a few runs but as expected it has trended right back to it and now the nam is hinting at the same posibility. The Euro has been all over the place with the cutoff low so have discounted it with this forecast. I expect the nam and the gfs to come into full agreement by tomorrow...and expect the Euro and CMC to follow.

These Upper level lows are tricky so im not going to make a call map for this system...I expect the ULL and its 850mb cold pool to be centered over the state tuesday with temps ranging from freezing to the high 30's. Expect snow to start around tuesday around morning in east TN and snow could be heavy and wet at times with temps falling a little as it gets dark.

Wednesday morning will feature snow showers in the morning changing to rain/sleet in the evening...but the rain/sleet will be short lived as the cold front sweeps thru rather quickly bringing with it more snow showers which could be in the form of cold advection squalls which would automatically lay on top of what snow managed to lay on tuesday. With temps struggling to reach 40 on tuesday I can see how some areas could pick up 1-3 inches especially in northern sections. Depending on how much precip will be with the NW flow behind the cold frond.... it is very possible top see another inch or two.

I realize people at the NWS are wanting to wait to see if modeleing gets any better but I believe in giving people a heads up as soon as possible....and I am now confident enough to throw out some rough numbers

My predictions on snow accums are as follows
Southern Valley Chatanooga and Athens area  =  Coating to a dusting
Central Valley  Knoxville and Jefferson City area = Dusting to 2 inches as much as 3 locally
NE TN  Tri cities Morristown area = 1 to 4 inches as much as 5 locally
Plateau area = 3 to 5 inches with as much as 7 locally
Smoky Mountains = 6 to 9 inches with as much as a foot plus locally

All accumulations have an error rate of plus or minus 1 inch and these totals may be updated monday