ESSC Scientist Michael Mann and researcher Michael Kozar have released their prediction for the 2011 North Atlantic hurricane season, which starts on June 1st.
The prediction is for 16.25 +/- 4.0 total named storms, which corresponds to between 12 and 20 storms with a best estimate of 16 named storms. This prediction was made using the statistical model of Sabbatelli and Mann (2007, see PDF here), including the corrections for the historical undercount of events (Mann et al., 2007, see PDF here).
The assumptions behind this forecast are (a) that the current warm sea surface temperture (SST) anomaly (0.90 C from NOAA’s Coral Reef Watch, see SST anomaly image here) in the Main Development Region (MDR) in the North Atlantic persists throughout the 2011 hurricane season and (b) near-neutral conditions in the tropical Pacific during boreal Fall/Winter 2011 (see ENSO predictions here) and climatological mean conditions for the North Atlantic Oscillation (NAO) in Fall/Winter 2011.
For the first year, Mann and Kozar are testing an alternative model that uses "relative" MDR SST (MDR SST with the average tropical mean SST subtracted) in place of MDR SST. This model predicts a substantially higher 18.86 +/- 4.3 (i.e. between 15 and 23 with a best estimate of 19) total named storms.
In 2007, Mann and Thomas Sabbatelli predicted the exact number of named storms (15) for that season (see 2007 prediction). Mann and Sabbatelli predicted 8 to 15 named storms in 2009, with a lower range of 6 to 13 in the event of a strong El Nino (NINO3 anomaly +1 C or greater, see 2009 prediction). The 2009 season was relatively quiet with 9 named storms partially due to the development of a strong El Nino. Last year, Mann and Kozar predicted between 19 and 28 named storms, with a best estimate of 23 storms (see 2010 prediction). The National Hurricane Center identified 19 named storms during the 2010 Atlantic Hurricane Season (1 June 2010 to 30 November 2010).
Mann, M.E., Sabbatelli, T.A., Neu, U., Evidence for a Modest Undercount Bias in Early Historical Atlantic Tropical Cyclone Counts, Geophys. Res. Lett., 34, L22707, doi:10.1029/2007GL031781, 2007.
Sabbatelli, T.A., Mann, M.E., The Influence of Climate State Variables on Atlantic Tropical Cyclone Occurrence Rates, J. Geophys. Res., 112, D17114, doi: 10.1029/2007JD008385, 2007.
Last Updated: 16 May, 2011 3:19 PM