Diego was a major winter storm that developed off the coast of California the week of December 3rd. The storm traveled across the southern tier of the country and redeveloped along the Gulf Coast on December 8th. By Sunday, it regenerated off the Carolina coast, pushing copious amounts of moisture and wintry precipitation into North Carolina and Virginia. It’s track closely followed a “Miller A” type setup for a winter storm.
In retrospect, the majority of folks forecasting this event underestimated the amount of snow Central Virginia would receive. Days before the event, snow totals were quite low. The NWS out of Wakefield only significantly increased snow totals on the morning of the 9th. A progression of the snowfall forecast is shown below:
Watches and warnings posted on Saturday, December 8th:
By the morning of the 9th, Winter Storm Warnings were issued for the watch areas. The NWS forecast for Richmond the morning of the event.
The winter storm warning language:
