While a busted forecast absolutely sucks, especially when numerous people depend on what you have to say as they pretty much work their lives around what's going to happen with regards to the weather, the most important thing to know when it comes to weather forecasting is that it is an imperfect science. What does this mean? In simple terms it just means there is no way to get every forecast 100% right 100% of the time. There are just too many variables involved within our atmosphere which is incredibly, incredibly complex and these processes don't always work out the way it appears they will. In some instances, forecasts busts have a positive side to them. Forecasts busts allow the forecaster to look deeper into what went wrong and hopefully find some clues which can be used in the future. This is actually one of the most important things in forecasting and one of the key ways a forecaster can better him or herself.
My Forecast
Below are the two forecasts maps I created for this storm. The map on the left was made early Sunday afternoon with the final map, on the right, made late Monday afternoon:
My thoughts were that very heavy and intense banding would traverse over much of CT with extreme western fringes receiving a tad less and the far southeastern part of the state. I was thinking the system would track a bit further west than what actually occurred and based on my thinking that would have allowed for that very intense narrow band, called a deformation band, to setup somewhere in western or central CT. It was the area under this banding which had potential to receive 24-36'' and as you can see last night my thinking was that would be through much of central CT. Well the system ended up tracking a little further east and this allowed for the heavier banding to not work any further west than the I-91 corridor. This led to the heaviest snowfall totals occurring across eastern CT with central CT receiving much less and western CT much, much less. In a nutshell this is how the forecast worked:
Below is a screen shot of the radar taken at 3:18 AM this morning. The circled area is where the heaviest snowfall and the heaviest banding setup during the overnight hours. The much heavier more intense snows never really made it west of I-91 and remained just east of a Hartford to New Britain to Bridgeport line. Once the snow shield hit this corridor it came to a halting stop and overtime slowly eroded to the south and west:
West of this line we still had moderate to even heavy snow falling, however, snowfall rates weren't much more than 1'' to maybe 1.5'' per hour while across eastern CT, snowfall rates of 2'' to 3''...even 4'' per hour were quite common.
All in all a slight track further east than expected meant a further eastward placement of the heavier snow bands and subsequent snowfall totals.
The slight track further east also reduced the magnitude of the winds, particularly the further inland you worked. While too my knowledge I don't believe any official CT reporting station reached official blizzard criteria (official blizzard criteria is sustained winds 35 mph or greater and visibility 1/4 of a mile or less for 3-consecutive hours) blizzard conditions were present.
What To Take With These Potentially Large Storms
Any time storms of this magnitude are forecasted the one thing to remember is there will always be a "screw zone"...there is always going to be an area which receives much less snow than forecasted. As mentioned in a previous post, deformation bands are associated with rapidly rising air which is enhancing precipitation and precipitation rates. However, this will also lead to an area of rapidly sinking air which works to eat away at precipitation. Forecasting in advance where both these zones are axes will occur is simply beyond challenging. Since these bands are very narrow in nature and depend heavily on mesoscale factors, computer forecast models simply aren't precise enough to accurately forecast or predict where these bands will setup. Usually you just have to wait until the event is ongoing such as last night when it wasn't under after 2:00 to 3:00 AM when it became obvious where the banding would sit and pivot over.
What Can Be Done Differently In the Future?
There really isn't a right or wrong answer here. Each situation is quite unique and brings about its own special challenges. In the case of this system, there was a great deal of model consistency on a slightly west track meaning much heavier precipitation working well into western CT. However, at the last minute, guidance began to track slightly east and the track slightly east was just enough to move the heaviest snow into eastern CT.
In these situations it can be very difficult to relay information to the general public because people want precise details and they don't want to hear "maybe's" "if this happens"...they want exacts and unfortunately this is a field where you can't always give exacts. In my opinion, its just best to be as honest as possible, even if it means you're sounding unsure or contradictory or presenting ideas which seem to be from both sides of the table but that's a facet that comes with forecasting.
I know when I am looking at computer models and reviewing data and I'm looking at a situation in which it seems possible we could be looking at 12''+ of snowfall I get a little nervous...now imagine a situation like this where numerous data is indicating as much as 24"+...the nerves go crazy. This is because all it takes is one little thing to go wrong or one slight shift to completely mess up a forecast as a whole.
Too conclude, while many across central and western CT did not receive anything close to what was forecasted, many others did. Going beyond CT, even back across NYC and into NJ the forecast was busted heavily, however, extending into RI and eastern MA, the forecasts were nearly perfect...both with regards to snowfall accumulations, winds, and impacts. While the goal is to be as accurate and correct as possible for every individual person, sometimes forecasts involve more than just what someone got in their own backyard...the bigger picture can provide a much more telling story. So while your area may not have had much, there are many who were pounded hard and are dealing with much more in the way if impacts. Forecasts busts are awful and make a forecaster feel awful, however, at the end of the day that is part of the field and it always will be. All you can do is keep your head held high and continue to learn as much as possible through experiences and any resulting studies which are done.
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