Tuesday, December 9, 2014

2014 Season Summary

The 2014 Atlantic Hurricane Season had below-average activity, with a total of

9 cyclones attaining tropical depression status,
8 cyclones attaining tropical storm status,
6 cyclones attaining hurricane status, and
2 cyclones attaining major hurricane status.

Before the beginning of the season, I predicted that there would be

13 cyclones attaining tropical depression status,
12 cyclones attaining tropical storm status,
4 cyclones attaining hurricane status, and
1 cyclone attaining major hurricane status.

The season was in fact below-average, particularly in number of named storms (8) which was well below the 30 year average (12) and what I predicted. In addition, the season had the fewest named storms since the 1997 season. The number of hurricanes and major hurricanes were closer to average, and were higher than my predictions.

A weak El Nino event did develop by late spring of 2014, contributing to stronger upper-level winds across the Atlantic basin and inhibiting development. In addition, though sea surface temperatures were anomalously warm over the subtropical Atlantic basin, SST values remained near average closer to the equator; the Gulf of Mexico even trended below average during parts of the season, limiting development there (Tropical Storm Dolly was the only tropical storm-strength cyclone to exist there).

Adding to these factors was a near- to below-normal West African monsoon, which made tropical waves emerging into the east Atlantic less frequent and vigorous. Stable air over the Atlantic itself also inhibited cyclone formation. In contrast, the East Pacific basin had above-average activity, consistent with the presence of an El Nino. Most land areas in the Atlantic were spared significant damage this season, with only tropical storm landfalls in Mexico, Central America, and the eastern Caribbean, and a single landfalling hurricane, Hurricane Arthur, in the United States. A notable exception to this was Bermuda, which was hit directly by two hurricanes in a very short span (see below).

Some other notable facts and statistics concerning this season are:

  • Hurricane Gonzalo was the strongest storm of the season, a category 4 hurricane with 145 mph winds and a minimum pressure of 940 mb, making it the strongest Atlantic cyclone since Hurricane Igor of 2010
  • Hurricane Arthur made landfall in North Carolina on July 3 (EDT), making it the earliest in a season a hurricane has ever made landfall in the state
  • Hurricane Fay and Hurricane Gonzalo directly hit Bermuda on October 12 (Fay was a tropical storm at the time) and October 17, respectively, an unprecedented two direct hits in a six-day period for the island
  • Tropical Storm Hanna formed from the remnants of Tropical Storm Trudy of the East Pacific basin, which had made landfall in Mexico on October 18, dissipated, and crossed into the Gulf of Mexico

Overall, the 2014 Atlantic Hurricane Season was quiet, showing consistency with pre-season forecasts.

Sources: http://www.esrl.noaa.gov/psd/enso/mei/, http://www.ncdc.noaa.gov/teleconnections/enso/indicators/sea-temp-anom.php, http://www.noaanews.noaa.gov/stories2014/20141124_hurricaneseasonwrapup_2014.html