Strong Forecast for Tuesday Snows
White Christmas Winners & Losers Accurately Conveyed
Marginal Conditions Made For Relatively Complicated Forecast
Some of the more difficult forecasts take place in the lighter events, as small deviations from the expected amounts are often more discernible when it means a slushy coating versus 3", as opposed to 12" versus 15". This is especially true when the stakes are a bit higher as they were yesterday, since not only were early cancellation decisions looming, but the timing of the storm carrying into the predawn hours of Christmas Eve meant that it had immense implications on the prospects for a White Christmas. There were also some complicating factors at play given that the storm had to overcome both a very dry antecedent airmass, as well as marginal temperatures given the path of the disturbance tracking to the north of the region.
Be that as it may, the forecast ended up verifying quite well.
Forecast Results
Here is the Eastern Mass Weather Final Call versus the actual outcome.
Note that the amount of snowfall reports exceeding 2" are relegated to outside of I 495, as specified in the forecast map from Saturday night (left). Given that temperatures today are expected to rise well into the 30's, a white Christmas will likely be relegated to this locales having received at least approximately 1.5" of snowfall. Thus only the northwest edge of the "White Xmas possible" area is likely to meet the official criteria of having at least 1" snow depth on Christmas morning. The weaknesses to the forecast are that 2" reports from the western part of the state are lacking, and there are some 4" amounts in the southeastern corner of New Hampshire, thus coating to 2" and 2-4" ranges would have been more advisable in these areas, respectively.
Final Grade: A