Snow Friday Night or Just Hype?

There will be a band of moisture offshore Friday that will back in toward our area Friday night. At this time I estimate that there is a 40%-50% chance that it will back in enough to bring some snow into our area Friday night into part of Saturday. The chances are just as good that the precipitation will remain just offshore. Two of the models frequently used to forecast several days out are the GFS (Global Forecast System) and ECMWF (European Center for Meteorology & Weather Forecasting) models. In addition to the operational from each model, the models are run multiple times with slightly different initial conditions to determine how much small changes could affect the outcome. The GFS is run 20 times and the ECMWF is run 50 times. These additional forecasts are known as "ensemble members". When they are in agreement, there is a high level of confidence in the forecast. When they are all over the place, confidence is low. The images above show the 20 different solutions from the GFS model for Friday night (plus the average and the control run). 11 of these keep us dry, 4 of them bring snow in, and 5 have us right on the fringe. Stay tuned.