From NOAA

No major hurricanes formed in the Atlantic basin – first time since 1994

The 2013 Atlantic hurricane season, which officially ends on Saturday, Nov. 30, had the fewest number of hurricanes since 1982, thanks in large part to persistent, unfavorable atmospheric conditions over the Gulf of Mexico, Caribbean Sea, and tropical Atlantic Ocean. This year is expected to rank as the sixth-least-active Atlantic hurricane season since 1950, in terms of the collective strength and duration of named storms and hurricanes.

“A combination of conditions acted to offset several climate patterns that historically have produced active hurricane seasons,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center, a division of the National Weather Service. “As a result, we did not see the large numbers of hurricanes that typically accompany these climate patterns.”

Thirteen named storms formed in the Atlantic basin this year. Two, Ingrid and Humberto, became hurricanes, but neither became major hurricanes. Although the number of named storms was above the average of 12, the numbers of hurricanes and major hurricanes were well below their averages of six and three, respectively. Major hurricanes are categories 3 and above.

PHOTO: Suomi NPP satellite peers into Tropical Storm Andrea, the first storm of the season. (Credit: NOAA/NASA)

Tropical storm Andrea, the first of the season, was the only named storm to make landfall in the United States this year. Andrea brought tornadoes, heavy rain, and minor flooding to portions of Florida, eastern Georgia and eastern South Carolina, causing one fatality.

The 2013 hurricane season was only the third below-normal season in the last 19 years, since 1995, when the current high-activity era for Atlantic hurricanes began.

“This unexpectedly low activity is linked to an unpredictable atmospheric pattern that prevented the growth of storms by producing exceptionally dry, sinking air and strong vertical wind shear in much of the main hurricane formation region, which spans the tropical Atlantic Ocean and Caribbean Sea,” said Bell. “Also detrimental to some tropical cyclones this year were several strong outbreaks of dry and stable air that originated over Africa.”

PHOTO: OES East satellite tracks Subtropical Storm Melissa, the last storm of the season. (Credit: NOAA)

Unlike the U.S., which was largely spared this year, Mexico was battered by eight storms, including three from the Atlantic basin and five from the eastern North Pacific. Of these eight landfalling systems, five struck as tropical storms and three as hurricanes.

NOAA and the U.S. Air Force Reserve flew 45 hurricane hunter aircraft reconnaissance missions over the Atlantic basin this season, totaling 435 hours–the fewest number of flight hours since at least 1966.

NOAA will issue its 2014 Atlantic Hurricane Outlook in late May, prior to the start of the season on June 1.

From What’s Up With That?

A couple of days ago, Dr. Roger Pielke Jr. updated his famous graph of hurricane drought, and despite some ribbing from me on what could happen in May 2014, has confidently extended the drought out to the start of the hurricane season in June 2014: see Graph 1

No mention of the failure of the predictions in 2013, nor the fact that this year goes against wild claims made by alarmists of increasing hurricanes due to global warming, something Pielke Jr. also illustrates with a new graph:

Graph 2 shows total US hurricane landfalls 1900 through 2013.

The five-year period ending 2013 has seen 2 hurricane landfalls. That is a record low since 1900. Two other five-year periods have seen 3 landfalls (years ending in 1984 and 1994). Prior to 1970 the fewest landfalls over a five-year period was 6. From 1940 to 1957, every 5-year period had more than 10 hurricane landfalls (1904-1920 was almost as active).

The red line in the graph above shows a decrease in the number of US landfalls of more than 25% since (which given variability, may just be an artifact and not reflecting a secular change). There is no evidence to support more or more intense US hurricanes. The data actually suggests much the opposite.

Dr Ryan Maue adds:

Here’s sorted list of North Atlantic hurricane ACE numbers from 1950-2013 — this year tied for 5th lowest on record http://models.weatherbell.com/ace_thru_dec31_sort.dat

For more on this story go to:

http://wattsupwiththat.com/2013/11/25/2013-slowest-hurricane-season-in-30-years/