A Difficult Winter Storm to Forecast
UPDATE: There is a lot of lightning with this storm, some of it within areas of snow or sleet, as you can see below. Thundersnow was officially reported this afternoon at Culpeper and Stafford, VA; regular thunder reported at a dozen other NWS stations.
ORIGINAL POST: A great example of why forecasting is challenging work... let's say you believed the 4-KM WRF computer model which ran last night (this morning's new version won't be online until late afternoon). It predicted the radar would look like this:
But the current radar really looks like this:
In pinpointed the western precipitation shield right-on, but the eastern one was much further north than projected, and because it was further north, it was colder, giving the I-95 corridor a "surprise" snowfall, if this was what you were solely basing your forecast on. Since the eastern part of the equation is off, does that mean the rest of the model's predictions will be off? Maybe.
But remember, there are at least 20 other models out there to take into consideration. A meteorologist's job is to use his knowledge of similar past weather events, local geographical knowledge, and overall weather patterns, in addition to any models he might look at (he has to know their biases too).
