- three U.S. landfalling hurricanes, versus an average value of 1.7 since 1900, and
- an Accumulated Cyclone Energy (ACE) of 134, versus an average value of 103 since 1982.
North Atlantic hurricane activity varies greatly from year to year, including 5-fold variations in ACE. The number of U.S. landfalling hurricanes in one year has varied from 0 to 6. There were multiple landfalling major hurricanes in 2004 and 2005, but then there were no landfalls of major hurricane or Florida landfalls from 2006 to 2015. Notable recent failures in forecasts of seasonal Atlantic hurricanes were the intensely active 2005 hurricane season and the low activity in 2013.
CFAN’s first seasonal forecast for Atlantic tropical cyclone activity is based on a breakthrough in understanding of the impact of global climate dynamics on Atlantic hurricane activity. CFAN has identified skillful new predictors for the number of U.S. landfalling hurricanes and the seasonal Atlantic Accumulated Cyclone Energy (ACE), which integrates the duration and intensity of Named Storms.
CFAN Senior Scientist Dr. Jim Johnstone, who is leading CFAN’s seasonal hurricane forecasts, says: “There are several different signals that point to higher than normal U.S. landfalling hurricanes.”
How do CFAN’s forecasts for 2017 Atlantic hurricane activity compare with other forecasts?
NOAA Climate Prediction Center forecasts a 45% chance of an above normal hurricane activity, with a predicted ACE range of 75%-155% of the median. 
The Colorado State University team under the leadership of Phil Klotzbach forecasts normal hurricane activity, with an ACE forecast of 100 (with a mean absolute error of 30) and a near average probability of U.S. landfalling hurricanes. 
Tropical Storm Risk forecasts average hurricane activity with an ACE forecast of 98 (with a mean absolute error of 48), with a 40% probability that U.S. landfalls will be above average. 
CFAN forecasts an ACE value of 134, with a mean absolute error of 35, and above average U.S. Landfalls.
CFAN’s forecast is unique in making a specific prediction of the number of U.S. landfalling hurricanes. Further, CFAN’s forecast uses new predictors that potentially provide greater prediction skill for years when there is no clear signal from ENSO (El Nino/La Nina). To date, the 2017 Atlantic hurricane seasonal forecasts have been regarded by forecast providers as highly uncertain owing to continued ambiguity regarding the forecasts for ENSO.
CFAN’s research team has long-standing expertise in climate dynamics and tropical meteorology research and in developing operational forecasts of tropical cyclones on timescales from 1-30 days. This seasonal forecast reflects the first time that this expertise has been integrated into a seasonal prediction of Atlantic hurricane activity.
CFAN’s President, Judith Curry says: “Our research into the climate dynamics of Atlantic hurricanes is revealing untapped sources of predictability on seasonal and longer time scales. We anticipate being able to provide more skillful forecasts at longer time horizons.”
CFAN plans to issue seasonal hurricane forecasts for the Atlantic in June, August, December and April. Further information is provided by the Forecast Summary Report. Click here to request a copy.
More detailed technical reports on CFAN’s seasonal hurricane forecast are available through paid subscription. Additional information and interviews are available on request.
Climate Forecast Applications Network (CFAN) develops innovative forecast tools to help our clients manage weather and climate risks. CFAN’s world-class research team translates the latest research and forecast innovations into solutions for our clients’ most challenging weather and climate related problems. CFAN was founded in 2006 by Judith Curry and Peter Webster and launched under Georgia Tech’s Enterprise Innovation Institute VentureLab program.