Wanted to share this great learning opportunity because it ruined what would have otherwise been an exemplary forecast. Its easy to forget that H7 fronto is simply a snapshot within the atmosphere, and that the coveted cross hair sig usually aligns with the SGZ region to the NW of max H7 fronto, since it slants NW to SE throughout the column with heights....as does low pressure (unless it is stacked).
Super Bowl Sunday Snowfall Verification
Here is the Final Call issued on Saturday, as a point of reference:
versus reality:
A Case of Misdiagnosed Frontogenesis
The forecast was generally accurate, however, there was one glaring oversight that detracts a great deal from the overall forecast because involves the very heaviest band. The heaviest band of 8-12" extending from southwest of Boston down through northwest RI and NE CT was the result of an intense area of frontogensis that was misdiagnosed. Although the forecast did incorporate this:
What was neglected was the fact that the band of heavy snow usually extends to the northwest of maximum area of 700mb frontogenesis due to the way that it is slanted vertically throughout the atmospheric column, including the snow growth region. Thus the heaviest band of snowfall should have extended just to the north of the highlighted area of frontogenesis, which is precisely where the band happen to align.
The fact that this band extended further to the northwest than forecast entailed that these very heavy snows also fell into slightly colder air, which resulted in a narrow band of 8-12", whereas the forecast 4-8" fell further to the south.
This was a very large mistake that resulted in 3-6" being forecasted for that swath of real estate that was most heavily impacted with 8-12" in a very short amount of time. Thus the overall grade still suffers, despite an otherwise nearly flawless forecast.
Final Grade: C
