SREF Probability of receiving greater than 6″ of Snowfall. Image courtesy, Weatherbell.

In the weather world, you have long-range, medium-range and short-range forecast models.  You also have control runs and ensemble runs.  If you needed surgery for a medical condition, you would probably want a second, third or fourth opinion on your treatment options.  In the  weather forecasting world you want to look at the ensembles as they give you multiple opinions for the same run (with slightly different initialized inputs).  Here are the latest SREF snowfall probabilities at the three main airports for tomorrow’s storm:

Washington National Airport (DCA) — Green squares show snowfall potential every six hours (5 to 9″ looks about right); of course DCA could lose 4″ to melting and sleet hence the confidence in at least 5″

Washington-Dulles-International Airport (IAD) –  6 to 10″ looks reasonable

Baltimore-Washington-International Airport (BWI) – 6 to 10″ looks reasonable