12/12 - 8pm - Uh Oh.... Next Week Could Be Messy

I've been giving my two cents on this potential ice storm early next week for the last day or so, but I'm sorry to say that things have really gotten to a fever pitch in the last 24 hours. The GFS has been consistent, almost to the point of being scary, with this storm today. The NAM has differences in timing, temperatures, and precipitation amounts with both prior runs and the GFS. The potential playbook from the 18z GFS goes like this:

Rain creeps into the area on Sunday night and sticks around for Monday...




Cold air starts to creep into the lower levels on Monday night, producing sleet or freezing rain...




Colder air starts to filter into the upper levels as well, giving us a complete changeover to snow on early Tuesday morning, mixing with more sleet or freezing rain by the afternoon...



Then we warm up for Wednesday and we get a little more liquid rain. Sound complicated? You bet! I thought the crew at the Louisville NWS office summed it up best this afternoon:

THE HEAVIEST PRECIP WILL FALL FROM 0Z TO 12Z TUES ACCORDING TO LATEST MODEL GUIDANCE. WITH THIS IN MIND...SIGNIFICANT SNOW AND/OR ICE ACCUMULATIONS MAY BE POSSIBLE OVER SOUTHERN INDIANA AND NORTHERN KENTUCKY. SOUTHERN KENTUCKY LOOKS TO REMAIN MOSTLY RAIN AT THIS TIME.

Here a couple of key things to remember: 1) We're still 3 days from the start of this system, multiple things can happen in the models. 2) A slight change in temperature in the upper levels (namely 850mb) could make this a more snow-centered event, a nasty ice storm, or mostly rain. 3) It looks like we will go way above freezing by Wednesday, so we'll only see major problems for 48 hours tops if this occurs.

I wish I could speculate on accumulations at this time, but with the uncertainty in the sleet/freezing rain department, I just can't. If we get more mixed precipitation, snow amounts will be low, but ice accumulations could be an issue. It's the same way if we flip the two. I'll go into this tomorrow on the video forecast. Hopefully the models overnight can shed some more light on this situation.