Before I get to some adjusted forecast details for the rest of today into tomorrow, I want to say a few things about my obviously-overboard snow totals forecast, and why I (and a few others who similarly had called for very high totals) busted.
A major reason for all the “hype” regarding forecasts of a foot or more is because there had been very strong consistency and consensus among the medium/long range models like the European (which has a track history of doing well with winter storms) and even the GFS came around and supported the ECMWF solution of big totals. 9 times out of 10 when models are saying the same thing for several days to a week, it’s a signal that they have a good handle on the situation, especially when they closely match their ensembles. Everything seemed to make sense with what they depicted…the track of the storm such that *some* warm air + sleet would make it into VA as the low formed off the coast but that the warm air would *NOT* make it past a line from South Hill to Charles City & New Kent to Tappahannock. And the forecast totals continued going up as we got closer. I did not buy into the more extreme numbers like 22-30 something inches for Richmond, but looking at the general trend, I did feel comfortable with at least 12”.
Because of the overwhelming consensus among the global models (which is a rare feat with winter storms), I neglected to look at some other important sources of data like Skew-T plots (which show a cross section of the temperature and wind profile of the atmosphere) , which were strongly hinting at warm air aloft reaching Richmond and bringing more sleet our way. I have to give props to the NBC12 weather team for picking up on that crucial bit of information and being willing to stand by their call. I know they took some flak for being considerably lower than other stations andn forecasters. Needless to say I regret my error in judgement with this forecast, but I also believe that’s how you get better and continue building knowledge…learning from mistakes and applying those lessons to future endeavors.
So, that being said, more snow is on tap (albeit on and off) from that “wrap around” moisture today into tonight as this system starts to lift to our northeast, but accumulations will not be extreme. Perhaps another few inches but nothing crazy.
ADDENDUM: I realize there’s the temptation to wonder, “What good are computer models anyway?” Yes, forecast models have been wrong before, but in all my years of tracking weather and putting out forecasts on this site, this was without a doubt the biggest failure of the models I’ve ever seen. There are about eight forecast models (not counting the ensembles) used by forecasters, and 7 of those 8 got this system wrong with respect to the warm air aloft and the subsequent sleet. That’s extremely rare. During calm weather and your normal rain events, no one really notices how accurate these models generally are. All it takes is one mistake with a big storm system like this to raise questions, which is quite understandable given the high impact on people and businesses. Additionally, winter storms are very complex beasts. Of all the different types of weather we see, winter storms have the most “moving parts” where everything has to be just right to get snow, much less a monster system like this, which is dumping 25”+ over DC and other areas of the northeast. As I always say, we can try and forecast as best we can, but nature always has the last word.
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