Why was there so much more snow than predicted

Now that the big storm is over, I am looking at why this was such a poor forecast. The basic reason was a bit more cold air than expected, more moisture and it lasted longer. No one expected so much snow to fall from 4 AM this morning until mid-afternoon. Storms usually need to be at roughly 40 degrees latitude and 70 degrees west longitude to give us a major snow event.

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Meteorologists around here call this the benchmark. If a storm passes near the benchmark, and it’s cold enough, we are often in for a good snowstorm. This storm passed hundreds of miles further east than that typical spot for a major snowstorm. One of the reasons I was confident in not seeing this size snowstorm, was the predicted distance of the storm from our area. That prediction by the models turned out to be pretty good. Temperatures were also forecast to be about 4 degrees milder. As it turn out, it’s sort of a good thing it ended up being colder because heavy wet snow of these amounts would have been catastrophic to the power situation.I’ll be updating my weather forecasts on Twitter at @growingwisdom please follow me there.

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The northern part of the storm acted like a paddle wheel and pushed copious amounts of moisture into the area.

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This morning, the intensity of the flow of snow from the ocean increased as the storm sat spinning nearly in place to our east. Additionally, as the storm was sitting over the ocean, some extra energy in the atmosphere was riding south into the storm from New York. This helped keep the plume of moisture flowing west towards Massachusetts off the moisture rich ocean. To the north, in southern Maine just a few inches fell and to the south across Connecticut there was not nearly the intensity of snow.
In looking at the satellite photos from this afternoon it also appears that a small storm may have formed west of the main storm. I noticed a circulation south of Nova Scotia and much closer to New England than the main storm.

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Other meteorologists will have to evaluate this and see what they think. In the absence of surface observations over the ocean, satellite photos are the only real tool to do some evaluating of the storm. Sometimes a new storm can develop on the boundaries created by the initial one. When this happens, it tends to slow down the ending of the precipitation and enhance the amounts.
There were forecasting elements of the storm that were good. The coastal flooding and erosion part of the forecast was ended up happening on schedule. This gave people ample warning about this element of the storm. Tragically for a few families this meant losing their home, but fortunately, that damage wasn’t seen on more than a few structures. It will take several days to evaluate the extent of beach loss and what can be replaced this spring and summer. The first part of the storm was also reasonably well forecast, although there as a small pocket of heavy snow yesterday morning, that exceeded predictions. Taunton, Millis, Canton and other areas of the southwest suburbs of Boston got 4-8 inches of snow in that first burst, higher than called for. During the day yesterday the snow melted as it fell before resuming accumulating last night. It was the intense snowfall rates that began around 3 AM this morning that were not forecast. Everyone started changing their forecast maps to reflect the increase in snow, but even with those changes no one anticipated some areas nearing 2 feet of new snow from the entire storm. Going back to the beginning of the week, it looked like the impact of the storm would be minimal at best. Forecasts 5 days in advance are still not very good, but improving.
Storms are hard to forecast. As good as our technology is, we can still make enormous mistakes. I sometimes think the better we get, the more upset people are when the forecast goes wrong because busts like this one don’t happen so much anymore. As a kid I would wake up in the middle of the night and see the moon when a storm was forecast. I would then get this sinking feeling knowing the storm had gone out to sea. Those sorts of errors just don’t happen with nearly the frequency as they did even 10 years ago.
Anyone who is a meteorologist in this market takes great pride in being accurate. We stay up late looking at the models; we evaluate, analyze and ponder every available tool we have in order to give you, the public, the best information possible. Sometimes, even with the best efforts, it doesn’t turn out as we expected and Mother Nature gently or no so gently reminds me who is boss.
Gardening this week
Depending on how aggressive you want to be in the garden, March does begin planting season. Fava beans, peas, lettuce, radish, carrots, and other cold weather crops can be planted by the end of the month. Inside, you can start many of your seedlings this month. I generally start my tomatoes in the first couple of weeks of March, which is about 8 weeks before they will go into the ground. Early this month is also the time to prune your blueberry bushes. In this week’s video I show you how to keep your blueberry bushes healthy and yielding big, juicy berries.

I’ll be updating my weather forecasts on Twitter at @growingwisdom please follow me there.


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