A weather system passed through the Northeast on Thursday rather innocuously, bringing gusty winds and snow squalls. However, now over the northwest Atlantic Ocean, it’s transforming into a beastly low-pressure area that is explosively developing and could break records. It even triggered a rare state of emergency in St. John’s — a place used to whopper snowstorms.
The meteorological bomb is affecting parts of Newfoundland and Labrador in Canada with hurricane-force winds, hefty snowfall totals and whiteout conditions all but eliminating visibility. Just off the coast, 30-foot waves are beginning to build, as well.
“If the forecast works out like I think it will, this will be the single most intense storm I’ve experienced in my life,” said Eddie Sheerr, chief meteorologist at NTV News in Newfoundland.
Sheerr is anticipating the worst conditions to come as the storm passes just offshore east of St. John’s on Friday afternoon and evening, with “nearly 12 hours of winds sustained in the 40 to 50 mph range, and gusts nearing 80 to 90 mph.”
On Friday morning, St. John’s Airport in Newfoundland picked up four inches of snow in one hour.
Blizzard criteria have already been met at St. John’s Airport, with at least 6 hours logged by Friday afternoon. At that time, gusts were close to 70 mph, with sustained winds equivalent to a strong tropical storm.
Winds will become even stronger into Friday evening, perhaps approaching hurricane force. Gusts near 90 mph may be in the offing by nightfall.
Roughly 10,000 people in the vicinity of St. John’s were without electricity Friday evening. That number is expected to climb, perhaps significantly.
Meanwhile, the 20 to 32 inches of snow Sheerr is calling for in St. John’s could rank as the city’s single greatest one-day snowfall on record. Records at the airport date to 1942.
Some social media reports indicate close to three feet had fallen in a few locales by mid afternoon Friday.
Snow drifts of 8 to 10 feet also aren’t out of the question.
“If the snow [was] where this storm ended,” he said, it would make the storm impressive in its own right. However, the winds and waves will make it even more impactful.
Why the ferocious conditions? The system will be in the midst of undergoing “bombogenesis” as its northwestern flank slams Newfoundland and Labrador, unleashing an arsenal of extreme conditions.
As storms intensify, they expel more air than they ingest. That evacuation of air from the upper levels causes surface air pressure to drop. In general, the lower the air pressure reading, the stronger the storm. The rate at which the air pressure falls is an indicator of how quickly the storm is intensifying.
For a system to qualify as a “bomb,” its air pressure must plummet — decreasing by at least 24 millibars in 24 hours. Mean sea level air pressure in most locales is around 1015 millibars.
On Thursday morning, the fledgling storm was passing through the Northeast, with its minimum central pressure analyzed at 1009 millibars. A tightening gradient, or change in air pressure with distance, made for blustery winds over New England near the coastline. Gusts to 45 mph were clocked in Boston.
As of Friday morning, the storm appeared to be hovering in the mid 960s, with a shot at pressure readings dipping into the upper 950-millibar range during the evening.
Among the interesting elements of this storm is that the strongest winds won’t precede the storm but, rather, occur in its wake.
Newfoundland, Labrador and the Canadian Maritimes will be subjected to the storm’s “comma head,” a region of wraparound moisture that pinwheels back northwest of the low’s center. It’s in that zone that a band of mid-level frontogenesis — or a tightening temperature gradient across a short distance — will enhance upward motion and boost snowfall rates. Snow could thump down at rates approaching three inches or more per hour shortly after noontime Friday.
Meanwhile, a storm surge warning is in effect for parts of the region, as the storm’s persistent onshore flow could yield water levels running more than two feet above average in spots. Waves of 30 feet are possible near the coastline but could approach 60 feet well offshore.
The European wave model simulates a few 50-foot waves over the open Atlantic as far south as Bermuda.
The storm will begin to abate into the early morning hours Saturday. From there, the storm is slated to make a run at Greenland, arriving Sunday with 100 mph wind gusts in the nation’s southeastern coastal regions, and depositing a strip of up to two feet of snow. It could also affect Iceland, although less severely.