Extended-range Tropical Cyclone Genesis Forecasts at the National Hurricane Center

Extended-range genesis forecasts at the National Hurricane Center

Eric Blake, Todd Kimberlain and John Cangialosi National Hurricane Center

Dynamical computer models have been gradually acquiring skill in forecasting longer-range tropical cyclone (TC) genesis. In addition, previous research has identified intraseasonal patterns favorable for TC genesis (such as the MJO or Kelvin wave passage) that have the potential to add value to the model solutions in the medium range. Using these tools, a three-year experiment has been underway since 2009 at the National Hurricane Center to determine if it is possible to skillfully forecast genesis in the 54 hour to 120 hour range. Preliminary results suggest there is some skill, although it is less than the short-term genesis forecasts. If this experiment proves successful, these verification data could support extending the forecast length of the NHC Tropical Weather Outlook genesis products, which has remained steady at 48 hours during the past few decades.