September is peak hurricane season. We’ve already witnessed a swell of record-breaking storm activity this year, and there’s still two months left to go.
On Thursday, Hurricane Lorenzo became the largest and most powerful hurricane to make it so far east in the Atlantic. The storm’s quick growth was unusual for hurricanes in the Atlantic, which usually gain intensity further west.
Two weeks ago, six named storms were active at once in the Atlantic and Pacific, hitting a record first set in 1992, forecasters reported. The onslaught threw the National Hurricane Center into high gear.
“All four workstations in the NHC Operations Area are in full use this morning,” the center said in a Tweet.
All four workstations in the NHC Operations Area are in full use this morning as NHC hurricane specialists prepare forecasts on current & developing systems over the Atlantic & eastern North Pacific basins. @NWS @NHC_Atlantic @NHC_Pacific https://t.co/3TBiIEfPWT pic.twitter.com/453LzE1LaC
— National Hurricane Center (@NWSNHC) September 17, 2019
And earlier this month, Hurricane Dorian — the strongest recorded storm to ever strike the Bahamas — tied for the strongest hurricane ever observed in the open Atlantic, according to NHC estimates.
As for the overall number of storms, though, NOAA did not expect 2019 to be a record-setting year. So far, the Atlantic basin has survived 12 named storms and five hurricanes. The northeast Pacific, which has had a pretty quiet season, has seen 13 named storms.
But conditions are ripe for an “above-average” end to the season, said Phil Klotzbach, a research scientist at Colorado State University.
“We still have October and November to go, so it remains to be seen exactly how much above-average the season will end up being,” he said.
For the Atlantic basin, NOAA defines an active season as having at least:
- 13 named storms (winds of 39 mph or greater)
- 7 hurricanes (winds of 74 mph or greater)
- 3 major hurricanes (winds of 111 mph or greater)
- 111 Accumulated Cyclone Energy units (an integrated metric that accounts for frequency, intensity and duration)
Currently, we’re at:
- 12 named storms
- 5 hurricanes
- 3 major hurricanes
- 97 ACE (will be at 111 ACE before Lorenzo dissipates)
While forecasters initially predicted an average hurricane season, NOAA adjusted this prediction in August, saying that an end to El Nino activity could cause an above-normal Atlantic season. NOAA predicted 10 to 17 named storms, five to nine hurricanes, and two to four major hurricanes.
“One of the primary things that is likely behind the above-average season is the movement away from El Nino,” Klotzbach said. “The winds blowing over the tropical Atlantic were weaker than normal. Because of these weaker winds, there was less mixing and churning up of the ocean surface which promoted the warming that took place there.”
So what role does climate change play in this above-average season? A partial one, Klotzbach said.
“There certainly is a long-term trend for warming sea surface temperatures in the tropical Atlantic that is likely partially due to climate change, but I think most of what happened this year is just natural variability,” he said.
Penn State University meteorologist Michael Mann, however, believes climate change has been playing a much greater role.
“There is a direct linkage between climate change and these intensifying and more damaging storms,” he said.
(Photo: wikimedia commons)
Warmer surface waters mean more moisture, which allows for worse flooding and faster and greater storm intensification, Mann said. Climate change is also slowing down the jet stream, which means storms are more likely to stall upon landfall and cause damage.
With two months left to go, authorities are sending residents one message: Bw prepared.
“By far, the most important message that needs to be reiterated to the public at this time is that coastal residents need to remain prepared in case a storm strikes,” NOAA said.
This article originally appeared on USA TODAY
