The 2013 hurricane season can best be surmised in 2 bullet points:
-- well below the seasonal forecasts
The season began active enough as "Andrea" developed early in the season -- in early June -- & hit Florida as a tropical storm dumping heavy rain & spawning several tornadoes including 2 EF-1 tornadoes (Fernandina Beach
) on the First Coast (Duval & Nassau Co.). Heavy rains hit Fl. & Ga. as well.
The rest of the season was nothing short of quiet. While the number of storms was not remarkably low (though there were several short-lived &/or even borderline named storms), the intensity was well below avg.
The following storms have been summarized by the NHC of far:
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.
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."
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. Image below is "Andrea" as it approaches Fl. the first week of June (GOES East Satellite/NOAA).
From a forecasting standpoint, the long range forecasts for the hurricane season were way overdone (just 30% of avg. since 1981). Colorado St. University -- Dr. Bill Gray & Dr. Phil Klotzbach -- has issued a seasonal summary -- click ** here ** -- & try to explain why the forecast was off by so much. One of the points that I happen to strongly agree with is the atypical meridional flow that so dominated the East/NE Atlantic from midsummer through early fall. There are reports that CSU funding is lacking & that the seasonal hurricane forecasts could be suspended - click ** here **. Some high (low) points from the season according to CSU:
Special Characteristics of the 2013 Hurricane Season The 2013 hurricane season had the following special characteristics:
• Thirteen named storms occurred during 2013. This is the most named storms to occur in a year with two or fewer hurricanes in the historical record. The 1931 hurricane season had thirteen named storms but only three hurricanes.
• 35.75 named storm days (NSD) occurred during 2013. This is the fewest NSD since 2009 (30 NSD).
• Two hurricanes formed in 2013. This is the fewest hurricanes since 1982 - when two hurricanes also formed.
• No major hurricanes formed in 2013. The last year with no major hurricane formations was 1994. • ACE in 2013 was only 30 units. This is the lowest ACE for an Atlantic hurricane season since 1983 (17 ACE).
• No major hurricanes made US landfall in 2013. The last major hurricane to make US landfall was Wilma (2005), so the US has now gone eight years without a major hurricane landfall. Since 1878 when relatively reliable landfall data became available, the US has never had an eight-year period without a major hurricane landfall.
• The maximum intensity reached by any TC this year was 75 knots (Humberto and Ingrid). This is the weakest maximum intensity achieved by the most intense TC of a season since 1968 (Gladys - 75 knots).
• Humberto reached hurricane strength early on September 11. It became the second latest forming first hurricane of the year, developing into a hurricane just hours before the previous record latest forming first hurricane of the year (Gustav - 2002)
• Two TCs formed in the Main Development Region (south of 23.5°N, east of 75°W) prior to 1 August. The last year with two TCs forming in this region prior to 1 August was 2005. The median ACE of the 10 years with two TCs in the MDR prior to 1 August was 174 ACE units. The 2013 season clearly defied many of the typical pre-season climate signals.