Christmas is just a short five days away. Some of our numerical weather prediction models are still hinting at a chance that we may have some snow on the ground in the Rockford region. The Global Forecast System model, more commonly referred to as the GFS, is run by the National Oceanic and Atmospheric Association (NOAA). NOAA oversees such organizations as the National Weather Service (NWS) and the National Centers for Environmental Prediction (NCEP). Their GFS computer model is run four times daily and can produce forecasts up to two weeks in advance. Generally, meteorologists utilize GFS information from one to five days out, as anything beyond that becomes less accurate. So it is important to stay up to date on the ever changing forecasts. There are other weather prediction models, such as the North American Mesoscale (NAM) model, the Global Environmental Multiscale (GEM) or Canadian model, and the Integrated Forecast System (ECMWF) or European model.
Three images of the GFS model output for Friday into Saturday (Christmas Eve) have been posted here. The data and images show mean sea level pressure, precipitation, and thickness. It looks like the possibility of light snow is in the forecast for Friday night and into very early Saturday for Rockford at this moment. This model run also looks like the snowy system will intensify and impact areas just southeast of Rockford near the southern Chicago suburbs and into Indiana, Michigan, and Ohio. This is still something to keep an eye on, as the updated model runs may find a change in the track of this system. So right now, don’t give up hope for a white Christmas! -JA
This post was written by Joe Astolfi on December 20, 2011