Prediction of Seasonal Atlantic Basin Accumulated Cyclone Energy from 1 July

The Tropical Meteorology Project at Colorado State University currently issues seasonal forecasts for Atlantic basin hurricane activity in early April, June, and August. This paper examines the potential for issuing an additional seasonal forecast on 1 July, using a two-predictor forecast model. The two predictors are selected from the ECMWF Interim Re-Analysis (ERA-Interim) and explain over 60% of the cross-validated variance in post–30 June accumulated cyclone energy over the hindcast period from 1979 to 2012. The two predictors selected areMay–June-averaged 2-m temperatures in the eastern tropical and subtropical Atlantic along with May–June 200-mb zonal winds in the tropical Indian Ocean. The May–June-averaged 2-m temperatures are shown to strongly correlate with August–October 2-m temperatures in the main development region, while the 200-mb zonal wind flow over the tropical Indian Ocean is shown to strongly correlate with El Ni~ no–SouthernOscillation. In addition, each predictor is shown to correlate significantly with accumulated cyclone energy, both during the hindcast period of 1979–2012 and with an independent period from 1948 to 1978.