Grade time is here!
There's no rest for the weary, as we're already tracking another potential storm for the end of the work week, but in order for us to get better--and hold ourselves accountable--we need to grade our work.
Grading can't happen before the storm, and definitely not during. We review the data after the storm has passed and grade ourselves based on our final exam--all the major elements of our final call forecast.
Time to review...
Looking back, we did a very nice job throughout this aspect of the forecast. We predicted onset to take place between 9-11pm, and were within an hour of that for southern CT. We accurately called the earlier morning hours for moderate snow to push in, and although it wasn't actually stated on our website version (oversight on my part), we saw the worst of the storm from 10am-4pm (which was mentioned on FB). Excellent job here.
Another excellent job. We called for maximum wind gusts between 35-45mph inland and 40-55mph at the shoreline. We said it'd be enough for near blizzard to blizzard conditions to but not enough for widespread damage, and that was accurate. We did think outages would be scattered, and I don't recall seeing any serious outages. If we could go back, maybe we'd probably go with isolated outages, but we were close enough.
We saw a peak gust of 45mph in Torrington, which was impressive, and peak gusts of 48 in New Haven, 46 in Groton, and 66 at a Wxflow station in New London. That last gust was not reported by the NWS so it may be elevated or isolated.
Snow intensity/road conditions
More good stuff. We called for the standard 1-2" per hour and predicted 3-4" rates as well. We were not as specific as we should have been with the latter, but that's fine. Both seemed to verify with a SWS issued for parts of southern CT later in the storm.
This led to bad road conditions. Over 500 call for assistance on the highways were reported.
This is the one that really hurt. In what was an otherwise great exam, we got tripped up on the multiple choice section here. You hate to see it, especially since this is the only thing people tend to care about.
We called the extreme banding. That happened. We called the high ratio snow in the biggest bands. That happened.
But we busted in the central zone. The forecast of 12-18" was way too high. We think the combination of subsidence due to banding in eastern CT and high winds aloft causing less efficient snow growth led to that forecasting miss.
For the most part, we did well with our 6-12" zone in western CT, but NW CT seemed to underperform. In eastern CT, we did excellent, but there was extreme banding there too, with a place like Tolland ending up with over a foot, but Columbia just a few towns over barely getting 6-7 inches. This was replicated in other parts of the state too. Torrington had 6.5" and 4" in town. Part of Monroe saw barely anything, while there were a 5.6 and 7.5" readings. Norwalk had 6, 7, and 9" totals!
Killingworth reported 5" while Clinton not too far away reported over 16"! That's an insane gradient, which we predicted, but we don't get credit for predicting how we'll be wrong.
Looking back, we could have expanded the 6-12" zone through the CT River Valley. Overall, we didn't have a statewide bust here, and as GP notes, trying to forecasting banding in this case was a nearly impossible task, but it was disappointing nonetheless.
Final not here. SE CT jackpotted! So much for climo! This was your storm!
We called for a high impact event, and it was. Storms are not just snow totals. The combination of wind, cold, and near blizzard to blizzard conditions made this high impact, along with most snow totals. No, this wasn't high impact everywhere, but in the broad scheme of things there was a high statewide impact. That's what we forecast for.
In the end, extreme banding and poor snow growth made the difference between a high end and historic event. The storm track met in middle of far west solutions 24 hours earlier and far east solutions day of on the guidance. We saw elongated rather than dual lows which allowed for more efficient snow and banding further east, but not enough for a more consistent shield.
Overall, we did well. That central zone snowfall bust will haunt me a bit, but it was always a moving target because we knew there would be a lot of winners and losers in the extreme banding. We really nailed the other impacts, but snow accumulations hurt what would have otherwise been a stellar grade for a big ticket event.
Winds/Power Outages: A
Snow Intensity/Road Conditions: A
Snowfall Accumulation: C- (note this is weighed 1.5x the other factors)
Overall Impact: A-
Final Overall grade: B+
Thank you for reading SCW.