12:30p.m. Saturday Update

From Chief Meteorologist Craig Carnesi...

Just a quick upadate on next week's possible winter weather. For an update on this weekend's forecast and next, be sure to join meteorologist Jason Myers on the KRBC News tonight at 6 & 10.

Now, you always hear meteorologists talk about computer models. They are one of, if not the best aid in forecasting the weather. The only reason computers will never replace people when it comes to forecasting the weather is because sometimes they are wrong, and sometimes they change their mind more times than I do about what tie to wear.

One of the models we use, known as the GFS, or Global Forecast System, has really been "flip-flopping" but is getting a little more consitent. This model was the first to show the winter weather and was the model that was consistently showing 3 to 5 inches of snow/ice. As of late though, this model has really backed off and has kept temperatures above freezing and all precipitation as liquid. The only problem with this is, the GFS has a tendency to show temperatures much warmer than they will end up being during winter. This is what we call a warm bias. More on this in a minute.

Now, on the other end of the spectrum, the NAM, or North American Mesoscale, or North American Model, is consistently showing the very cold air arriving with no problem. The NAM also shows much better precipitation chances than the GFS as well.

Now, before looking at all of this, a meteorologist must look at current conditions to see what is actually happening the atmosphere. Well, it's only 22 in Hastings, NE at 12 p.m. Saturday. Then temperatures drop down into the teens North of there. So, there is plenty of cold air for the cold front to tap into. Basically, we just have to wait until Sunday evening, when the next cold front arrives, and see exactly how much of that cold air moves our direction. But, with that much cold air bottled up, that's why I believe temperatures will be much colder than the GFS that I mentioned earlier is showing.

Now, there are numerous other computer models, but these are two of longer-range models we use. As we get into Sunday, most of the medium range models and short range models will begin to pick up on this event. So, by Sunday afternoon, we will have a much better idea of what is going to happen.

I just wanted to give you a little insight into what the KRBC team of meteorologists use to forecast the weather for you.

And yes, today is my day off, and yes, my wife is getting annoyed that I'm on the computer and not helping her clean the house before my parents arrive for Christmas weekend. The only answer I have is, she married a weather geek, and a weather geek I will always be!