- Winter Storm Riley is hammering the East Coast with rain, sleet, and intense winds on Friday.
- The nor’easter is undergoing the rapid intensification process known as “bombogenesis,” a term meteorologists use to describe storms that become so-called bomb cyclones.
- This isn’t uncommon for nor’easters, but this one is expected to be particularly bad.
- Record flooding in Boston is possible for the second time this winter.
At the start of the year, a nor’easter intensified so quickly that it became what meteorologists call a “bomb cyclone.”
It appears that’s happening again.
The storm is undergoing a rapid intensification process called “bombogenesis,” which means its central pressure is dropping quickly (an indicator of a storm’s strength).
So-called bomb-cyclone conditions are not uncommon for nor’easters, but this one could be even more intense than the storm earlier this year and cause record flooding and intense damage.
The Boston branch of the National Weather Service warned of major coastal flooding and beach erosion Friday night. Earlier in the day, it said this storm is on par with the most intense nor’easters in recent history, including storms in December 1992 and April 1997.
“Many have asked how this event will compare to January 4,” the branch said in a statement on Friday. “Our thinking is there will likely be more structural damage in this event given the larger waves and occurring over multiple tide cycles. Many neighbourhoods will likely become isolated, some for extended periods of time.”
On Twitter on Thursday, NWS Boston warned: “Take this storm seriously! This is a LIFE & DEATH situation for those living along the coast.”
Those in affected areas should listen to local authorities and heed advice to stay indoors or evacuate as requested.
What to expect
As of 5:40 p.m. ET, all flood watches had been discontinued in the Tri-State area, according to the New York branch of the National Weather Service, but moderate to major coastal flooding was still possible – with inundation of 2 to 3 1/2 feet in vulnerable areas, the office said.
Potentially vulnerable areas include, Lower New York Harbour and the Bays of Long Island. South Queens and South Nassau/Riverhead were considered the most vulnerable, according to the National Weather Service assessment
In its 10:25 p.m. update, the Weather Channel reported “damaging winds” from western New York to the mountains of North Carolina.
A map of the Tri-State area showed maximum wind gusts of 41 mph in Boston and 33 mph in Philadelphia.
But in Barnstable, Massachusetts, wind gusts reached 93 mph on Friday night. Wind gusts on Nantucket Island clocked in at 89 mph, the Weather Channel reported.
Earlier Friday, the storm had knocked out power to more than 500,000 homes and businesses and caused more than 2,000 flight cancellations. Those outages could potentially last several days.
“Riley will be a Nor’easter with major impacts on many different scales across a large area,” Tom Niziol, an expert on winter storms with the Weather Channel, told Business Insider in a statement.
Maryland Gov. Larry Hogan declared a state of emergency on Friday night due to power outages and dangerous winds. “Please use common sense, heed all warnings, and stay inside and off the roads if possible,” Hogan said in an emailed statement.
The heavy winds are expected to batter the coasts and inland mountain regions, knocking down trees and power lines.
They’re also expected to exacerbate coastal flooding. In Boston, experts are predicting moderate to major flooding for three tide cycles.
A 3-foot storm surge is coming into the city on top of approximately 11-foot tides, with two high tides Friday and one on Saturday.
The flooding could set records in the city and be worse than the January 4 storm, during which parts of Boston were inundated with icy water.
Meanwhile, massive waves are stretching down the coast to Bermuda.
“All in all, Winter Storm Riley will bring in the month of March like a roaring lion,” Niziol said.
NOW WATCH: Briefing videos
Business Insider Emails & Alerts
Site highlights each day to your inbox.