Some Significant Snow Possible ... Again!
Not Another Winter Storm!!!
For Southern Kentucky, actually yes we will see another winter storm. The short term forecast today brings some light drizzle and mist to most of the area. Dense fog is also reducing visibilities to under 1/4 mile just south of Louisville, so please you some caution this morning.
Even if you are not in the Dense Fog Advisory, remember there are many other areas reporting fog.
Now onto the more interesting parts of the forecast. A storm is going to ride along the Gulf Of Mexico. This puts part of our area in the sight of this storm. I have to tell you this is a very tricky forecast because the northern extent of the snow is going to be tough to pin and there will be a tight gradient where the snow amounts increase substantially. As we stand, the NWS has a Winter Storm Watch for Southern Kentucky.
Notice, the Munfordville, Greensburg, Columbia, etc. are all included in the watch. I do indeed think it is possible that a winter weather advisory may be necessary as for north as Bullitt County to Breckinridge County to Franklin County of Kentucky.
This is what we call back side snow. It means that cold air must filter in before we can transition to snow since we are sitting in the mid and upper 30s this morning. That critical time frame for Louisville would be around midnight and 4 am near Munfordville and 5 am near Columbia. North of the river there is nearly no real concern of significant accumulation.
Now for amounts. I am not buying a lot of what the computer models are indicating. A lot of blogs post the raw snowfall outputs from the models, but if you watch those you will notice they are all over the place, so if they are unreliable it doesn't seem wise to scare you. Remember computer models do not determine reality, they simply give their best estimate with tons of approximations. They are oscillating all over the place on amounts, so I want to rely a little more on traditionally what these situations can produce. The GFS seems to be initializing and forecasting the tier of upper lows well. This is the GFS for around 1 am.
The important part at this time frame is the upper level winds over central and south central Kentucky will diverge aloft. This "deformation zone" will create a band of moderate to heavy snow.
My totals look like this... I think nothern Jefferson county could see up to a light accumulation and in southern Jefferson County could see up to 1" of snow. Southern Kentucky and Eastern Kentucky will see significantly higher totals. E-town to Leitchfield to Munfordville to Columbia will see 1-3" of snow with higher amounts the further south you go. Take a look at my snowfall accumulation map so you can pick out your area.
We will try to update totals as the day progresses. School closings and delays seem likely for some parts of our area tomorrow.