Less snow?! The change in Tuesday’s nor’easter precipitation shift, explained

DEDHAM, Mass. — Tuesday’s nor’easter ended up shifting on a track that took the storm about 50 miles south of where it was previously forecast to hit, drastically altering expected snowfall totals in Massachusetts.

Tuesday nor’easter: Latest timeline, expected snow totals, maps, threats after storm shifts

The late (Monday afternoon) change in the forecast came after towns and cities called off school, announced snow emergencies, and implemented winter storm parking bans.

As a result of the track shift, the band of higher snowfall remained south of Boston and the Massachusetts Turnpike. Points along the South Shore and the upper Cape were still expected to see up to 9 inches of snow but with much lower totals than initially thought to the north and west.

Forecast models over the weekend heading Monday showed the possibility of more than a foot of snow across much of the Bay State.

The whole axis of heavy rain moved about 50 miles south since yesterday... That means the heaviest snow will fall south of the Mass Pike instead of reaching the MA/NH border. @Boston25 #mawx #nhwx #newengland pic.twitter.com/EV9Nh4CWLw
— Shiri Spear (@ShiriSpear) February 13, 2024

Boston 25′s Gene Lavanchy asked Boston 25 Meteorologist Shiri Spear, “What happened?” She explained.

“We had to shift those bands with the heaviest precipitation. A little shift can make a big difference in those numbers. The numbers obviously went down,” Spear explained. “You had the snow days, with little to no snow.”

The Boston 25 Weather team had cautioned since last week that the track of the storm was subject to change, but Spear called this occurrence “pretty unusual.”

“It’s pretty unusual for it to change that late in the game, so I understand why the [school] cancellations were done early,” Spear said. “I just have a feeling with the next storm it’s going to be last minute, morning of.”

In a post on X on Monday night, Boston 25 Meteorologist Tucker Antico wrote, “One of the greatest swings in data that I can remember. Have to save this one for the records, though I hardly doubt I’ll forget it.”

Euro Ensemble. 12Z Sunday to 12Z Monday.

One of the greatest swings in data that I can remember. Have to save this one for the records, though I hardly doubt I'll forget it. pic.twitter.com/potD25krke
— Tucker Antico (@tuckerweather) February 13, 2024