(12-15-10) Winter Storm Warning in Effect

As expected, we've now been upgraded to a Winter Storm Warning in effect until 1pm Thursday. The last few model runs since yesterday have started to trend a bit warmer in our area, seeming to put the rain/snow changeover line to our north. It's now looking like Dubois County will get a fair amount of freezing precipitation.

So what can we expect? Tonight temperatures will stay nearly steady. At 6pm it's 28F and we'll stay in the upper 20s through most of the night, possibly rising to near freezing by morning. Right now the temperatures in the mid-atmosphere (around the 850mb level) have not risen above freezing. As warmer air surges in from the south overnight into that layer, expect it to go above freezing and produce freezing rain for us. In fact, the National Weather Service has placed us under a moderate risk for freezing rain. What this means is that we'll likely start out as an all snow event and then transition to a snow/sleet mixture before changing over to all freezing rain sometime overnight.

So how much can we expect? It appears that we'll have plenty of QPF to work with. QPF is Quantitative Precipitation Forecast and it is a graphic the National Weather Service puts out to give forcasters an idea of how much precip to expect. It puts our area in the 0.25 - 0.5 inch range. Remember this is liquid, so we have to convert to snow using a 10:1 ratio for wet snow. If it were all snow, we'd be in the 2.5 - 5 inch range. Since it won't be all snow, it's really going to depend on how much falls initially as snow and when the changeover occurs. It's highly likely that we could see some heavy snow showers at the outset of this event as it moves into our area overnight. That could give us a quick 1-2 inches of snow, followed by a solid quarter inch of ice in the form of sleet and freezing rain. This storm is really tricky to predict and really the best way at this point is to stop looking at the models and see what actually happens in Kentucky in a few hours. That will give us a solid idea of what to expect.

As for the rest of the week, it will be cold. Friday looks to be a gloomy day with highs in the upper 20s. The weekend looks dry overall, with just a passing flurry or two. Nothing significant, but highs will only be in the upper 20s again. In fact the whole 7 day outlook looks to be well below normal for us in temps. Lows will be in the teens throughout the forcast.