It was on June 16, 1972, that a disturbance in the northwestern Caribbean became Tropical Storm Agnes, which went on to become one of the deadliest and most destructive tropical cyclones on record.
As the name indicated, it was the first tropical storm – one with peak winds of 39 mph – of that Atlantic Basin season. It formed right around the “normal” time for a first storm, and that was about its only claim to normality.
The 2017 season already has had an "A" storm, Arlene in April, and the National Hurricane Center’s outlook sees the potential for two more named storms by early next week. Typically a third one doesn’t occur until July 6.
Before those nascent storms earn names, we might get a peek at one of the changes the hurricane center made making in its advisory system under erstwhile director Rick Knabb, who has rejoined former employer, the Weather Channel. (The hurricane center hasn’t yet named his successor.)
For the first time the hurricane center has the option of posting advisories on incipient disturbances before they become depressions or tropical storms.
Also, in addition to the projected paths, the center will be generating “wind arrival” maps to let people know when they can expect to experience tropical-storm, another Knabb initiative.
Farther along in the career of potential storms, the hurricane center will continue to issue advisories for tropical storms even after they move into the higher latitudes and lose their so-called tropical characteristics.
The center took extreme heat in 2012 for dropping advisories after Sandy became “post-tropical” and proceeded to rip apart Long Beach Island, set a record for power outages inland, and flooded New York City.
One thing that won’t change is the Saffir-Simpson hurricane-rating scale, whose weakness was underscored by Agnes in 1972.
The hurricane scale takes into account only peak winds, with 74 mph being the threshold for a hurricane, and 111 mph for a “major hurricane.”
Agnes, which became a hurricane in the Gulf of Mexico before reverting to a tropical storm, later merged with another system and mutated into a destructive rainstorm, doing much of its damage long after it was stripped of hurricane status.
It was blamed for more than 120 deaths, 45 in flood-ravaged Pennsylvania. Touring the region by helicopter, President Nixon declared: “We saw devastation everywhere.”
Improving upon the wind scale has been an elusive pursuit, Knabb said in an interview last week.
“We in the meteorological community have been debating and thinking and discussing that for years and years,” said Knabb, who became the center’s director in 2012. )Incidentally, it is still searching for a replacement.)
“There is no one scale that could possibly convey all the wind and water hazards,” he said. “There are too many factors.”
For now, he said, the best strategy is to talk about individual hazards – forecasts that address how much rain could how, who strong the winds might be, how far a storm surge might penetrate.
As Agnes proved, it's not always just about the wind.