Six hurricanes, three of them major, and 12 named storms overall. That is what we have seen so far in the 2017 Atlantic hurricane season. The first of those six hurricanes was after the peak of the season began Aug. 1. As of Sept. 13, peak season is roughly half over.
The National Oceanic and Atmospheric Administration predicted an active Atlantic hurricane season in May, then upped their projections in a scheduled August revision to forecast an even busier one, predicting 14 to 19 named storms, five to nine hurricanes, and two to five major hurricanes this season.
While we have had 12 named storms so far this year, the first hurricane didn’t appear until Franklin on Aug. 9, and the 35 days since then have brought five more, already taking us into the range predicted by the NOAA for the entire season. We also are already in the projected range for major hurricanes.
There are still 48 days until hurricane season ends Oct. 31.
“We’re only at the halfway point. We’re still in the peak of the season. This season is not over,” said Dennis Feltgen, spokesman for the National Hurricane Center. “We’ve got a lot of season to go. It was expected to be an active season, and it is.”
The current standard-bearer for active hurricane seasons is 2005, which gave us so many named storms that the hurricane center had to switch to Greek letters to keep naming them (they skip the letters Q, U, X, Y, and Z because there are few common names that start with them). The stand out among them was Hurricane Katrina, which devastated New Orleans and the surrounding Gulf Coast region.
Feltgen did not want to draw comparisons between 2005’s Atlantic hurricane season and the current one. When asked if 2017 could be as bad as 2005, he would only offer a pensive, “I hope not.”
2005 vs. 2017
By this point in 2005 there had been 14 named storms versus 2017’s 12. There were seven hurricanes, four of them major, through Sept. 13, 2005, while 2017 has had six hurricanes and three major hurricanes through the same point.
However, 2017 has already seen two major hurricanes make landfall in the continental U.S., both of them as Category 4 storms, while 2005 brought Hurricane Katrina to our shores as a Category 3 the first week of September.
From Sept. 13 forward in 2005, the Atlantic saw 12 more named storms, including seven additional hurricanes, of which three were major.
If 2017 progresses in the same fashion, we would see 24 named storms by the end of the season, including 13 hurricanes and six major hurricanes. That would put us above estimates in every category.
Four additional tropical cyclones developed in 2005 after the formal end of the season, with the last, Tropical Storm Zeta, forming in late December of that year and not dissipating until January of 2006. This is a stark reminder that nature does not abide deadlines.
Fun fact: the hurricane center recycles storm names every four years, retiring the names of massive storms that do extensive damage, meaning that with a few exceptions we are operating from the same list of names this year that we did in 2005.
Records set in 2017
Even if 2017 does not eclipse 2005, this hurricane season has already been record setting in a number of ways.
Hurricane Irma maintained maximum sustained winds of 185 mph for 37 hours. Only Hurricane Allen in 1980 had faster winds. Setting aside the fact that those wind velocities tie it for second fastest sustained winds in history, the duration of those speeds makes Irma the strongest Atlantic hurricane on record, according to Feltgen.
Meanwhile, Hurricane Harvey set a record for most rainfall in the continental U.S. with 51.88 inches according to the National Weather Service.
This also is the first year where two hurricanes with wind velocities of 150 mph or greater have coexisted in the Atlantic, according to Colorado State University research scientist Philip Klotzbach.
Why has the 2017 Atlantic hurricane season been so active?
An El Nino that was expected to combat strengthening tropical systems had not developed as of early August, according to the NOAA.
The first half of the 2017 season saw six named storms, half of what is normally seen during years when most named storms occur in the peak part of the season. Statistically, in years with many early named storms, there also are more named storms in the peak period.
Warmer waters and low wind shear play directly in to the development of tropical cyclones, and waters and wind in the Atlantic have been very conducive to the formation of storms like Harvey, Irma and Jose, according to the NOAA.
Nobody can say for sure how many more storms there might be this season. Even timing the end of the season isn’t a sure thing, as 2005 proves.