The day before the storm hit, I mentioned at work that it might be a top 5 winter storm in my 11-plus years at the station. I think it lived up to that billing.
It was January 4. Thursday. An unusually intense low happened to take the ideal track for Aroostook County to receive heavy snow. By the way, when you hear “intense low,” that means that the central pressure, where the lowest pressure is, is unusually low. And anytime that happens, you are assured of a lot of wind, both during and following the storm, and in this case, we had two days of post-storm wind. That wind had plenty of snow to blow around, as amounts ranged from 12 to 22 inches across The County and western New Brunswick. The official total at Caribou was 18.8”. Getting a foot and a half of snow in a single storm is not a common occurrence in northern Maine. But it happened because this storm took the perfect track, up through the Bay of Fundy, and into eastern New Brunswick. The heaviest snow and heaviest snow rates are found northwest of the low pressure center, which is where we were.
Now, the title of this column refers to what a longtime plow operator told me. He’s a guy who works one of the more heavily traveled roads in Aroostook County. He told me that the post-storm drifting was the worst that he had seen in his 12 years on the job.
I also ran into two different people at the post office who said that the evening conditions driving from Presque Isle to Caribou on that Thursday evening were the worst they had ever seen, and each person is a longtime resident.
The week prior, following the Christmas storm, and the widespread whiteouts which followed on Boxing Day, guidance had been hinting at a strong storm around the 4th of January, and sure enough, that turned out to be the very date. The storm brought a “new” term into the public consciousness, a term that meteorologists don’t use, but which the media did: “bomb cyclone.” The thing is, there is nothing new about a cyclone (which is just another name for a low pressure system) bombing out. So by using the term, “bomb cyclone,” it simply means a low that has bombed out. OK, that’s great. But what does it mean? When a low bombs out, it means that the central pressure has decreased by a given amount over a 24-hour period. The pressure fall that is the minimum threshold for a low bombing out, is 24 millibars (0.71” on the scale you’re probably more used to) in 24 hours.
The atmospheric conditions were ripe for this low to bomb out off the U.S. East Coast, and bomb out it did. In fact, the storm (lows are sometimes called “storms”) more than doubled the baseline rate of 24 millibars in 24 hours. As mentioned, intense lows come with a lot of wind, and the highest wind gust from this storm was 106 mph, on the western side of Cape Breton Island in Nova Scotia. There was also a hurricane-force wind gust of 75 mph recorded along the Massachusetts coast.
This was an unusually intense low (it was analyzed at 10 p.m. on Jan 4 at 949 millibars, 28.02 inches when the center was near the mouth of the Bay of Fundy). If you are a weather hobbyist, you know that is a very, very low pressure. And when you get down that low, the wind will crank for a while as the storm pulls away.
That’s the point we tried to hit as hard as we could, that two days of blowing and drifting would follow the storm, and that both the 5th and 6th would see significant travel impacts, even though the blizzard and winter storm warnings would have been dropped a day or two before. Warnings such as these are usually ended after the new snow has stopped falling, and that has a tendency to get people to let their guard down.
Sometimes, as we saw, very significant impacts continue, long after the falling snow has ended.
By the way, we received some questions as to why we showed no blizzard warning for New Brunswick.
Our new system picks up warnings from both the National Weather Service, and Environment Canada. The latter had issued a winter storm warning, but not a blizzard warning. That’s why the Caribou-issued blizzard warning stopped right at the border.
Ted Shapiro holds the Broadcast Seal of Approval from both the American Meteorological Society and the National Weather Association. An Alexandria, Va. native, he has been chief meteorologist at WAGM-TV since 2006. Email him at tshapiro@wagmtv.com.
