WHAT HAPPENED TO THE MODELS ON THE WINTER STORM CASE?
We have looked at this case in some detail (as available resources permit). 1) All models agreed at the 48 hour range that the short waves in the northern and southern streams would phase in and a sizable storm would result for NYC and elsewhere. As I understand it, the extended range progs (MRF and ECMWF) had been doing repeated flip-flops in the days leading up to this point, but at this time the AVN, NGM and Eta all had pretty much the same scenario predicted, with the Eta characteristically more detailed and with more intense snow over NYC. 2) At the 36 hour range, the predicted scenario by ALL the models changed and the northern short wave didn’t phase in. The southern wave produced a very modest storm with different track resulting in no precip at all over NYC. This new scenario was predicted at shorter ranges by ALL models and verified. 3) We have looked at some of the ensemble output with a new tool that is capable of tracing back areas of uncertainty to their origins. It is cl
