Here is a snapshot of what might happen. It’s a little small but you can see that the heaviest stuff is in southern Indiana. Its a very tight gradient of snowfall. For instance, it goes from 2 inches in SE Jefferson County but at the river its 6 inches. We are looking for 1-3 inches south of the river, just north of the river in a narrow band some 3-6 inches and then in an area in Southern Indiana that would include perhaps Paoli and Seymour and points to the northwest, 6-12 inches. So…why not so much snow?
There is a developing consensus that we will get rain for much of the day on Friday. Perhaps some sleet, especially along and just north of the river. The way it appears now, we don’t get any snow until after midnight on Friday and the snow carries on overnight and through much of Saturday. Southern Indiana in the 6-12 inch area gets all snow the whole time. The extreme southern part of the viewing area will largely get rain with just perhaps some minor accumulations on Saturday.
Here’s the rub. First off, the models are in fair agreement but, the storm is just now starting to get itself going and really doesn’t wrap up until late Thursday night. It won’t be until that time that we will be able to see exactly where it will track. So, if we assume that the current consensus holds regarding the general track, the specifics will be the variable. If the current thinking is off by say, 30 miles to the East, then the heavier snow would shift and the 6 inch line would be pretty close to Louisville. If the track shifts 30 miles farther west, then the 1 inch line gets closer to Louisville. Keep in mind that the trends with the model runs for the last few days has been farther and farther west, which is what we had been looking at as a possibility. Now, does this mean that it will continue to shift west? It’s possible. Can it shift significantly to the East? I suppose it’s possible but not probable as that would be extremely unusual.
I suspect that the general track will hold true but the little variable with regard to the exact snow gradient lines will be troublesome. Again, I’m talking about a little wiggle of 30 miles which would alter things for many people dramatically. When you consider that the earth is 25000 miles around and the storm we’re trying to track really hasn’t even formed yet, it’s pretty tough for computers as well as people. Also remember that, regarding snow, if it were rain there wouldn’t be any question. Generally, the liquid equivalent of 6 inches of snow is .60 inches of rain and 3 inches would be .30″. In that situation, you might hear that we were expecting a quarter to a half inch of rain and everyone would say, “Okay, you got that pretty much right.” No big deal, right? But snow…people tend to squawk and call in with ridicule if we said 3 inches of snow and you got 6 inches instead. So it’s real tough. Even more so when you call for an inch of snow and instead you get a half inch. The difference in that is .10″ and .05″ of rain! That is really negligible but with snow….it’s really tough.
This should show itself Thursday. Tune in on TV and Jay will have some pretty good graphics to show you the story.