Feb 1-2 High Impact Winter Storm: Verification
Here is the Final Call for yesterday's winter storm:
And what verified for the sake of comparison:
While this was a good forecast overall, there were three rather glaring issues that distinguished this particular efforts from some of the best forecasts.
1) The residual forcing from the parent system that infiltrated western New England was a bit stronger than indicated on the Final Call. A range of 8-16" would have been a more accurate representation.
2) The area of subsidence in the CT river valley was overstated. A general 8-12 swath would have sufficed, as opposed to the 4-8" and 6-10" ranges employed. This is likely related to the forcing from the original parent low remaining somewhat stronger across western New England, as alluded to in forecast critique #1. This likely negated some of the subsidence and down sloping that otherwise plagues the CT river valley in deep layer easterly flow events.
3) The snowfall gradient near the eastern Mass coast was about as sharp as has ever been witnessed, thus this was obvious underemphasized in the forecast. The thermal layer in the lower half of the atmosphere near the immediate north shore, and over much of southeastern Mass, the cape and islands was not able to overcome the marine influence as much as anticipated.
Other slight critiques interior northeast Mass, where a couple of 20" reports from West Newbury and Wilmington slightly exceeded the 12-18" forecast range. Additionally, the 12-18" range over southwestern CT should have been extended slightly further to the northeast, given the stronger forcing with the parent low.
Final Grade: B-