The 2014 North Atlantic Hurricane Season: Penn State ESSC makes prediction

ESSC scientist Michael E. Mann, alumnus Michael Kozar, and researcher Sonya Miller have released their seasonal prediction for the 2014 North Atlantic hurricane season, which officially starts on June 1st and runs through November 30th.

The prediction is for 9.3 +/- 3.0 total named tropical cyclones, which corresponds to a range between 6 and 12 storms with a best estimate of 9 named storms. This prediction was made using the statistical model of Kozar et al. (2012, see PDF here). This statistical model builds upon the past work of Sabbatelli and Mann (2007, see PDF here) by considering a larger number of climate predictors and including corrections for the historical undercount of events (see footnotes).

The assumptions behind this forecast are (a) the persistence of current North Atlantic Main Development Region (MDR) sea surface temperature (SST) anomalies (0.29°C in mid-May 2014 from NOAA’s Coral Reef Watch) throughout the 2014 hurricane season, (b) development of a moderate El Niño (Niño3 anomaly of 1°C) in the equatorial Pacific during boreal Fall/Winter 2014-15 (Climate Prediction Center ENSO Discussion), and (c) climatological mean conditions for the North Atlantic Oscillation in Fall/Winter 2014-15.

If a milder El Niño develops instead (Niño3 anomaly of ~0.5°C), then the prediction will be slightly higher: 10.1 +/- 3.1 storms (range of 7-13 storms with a best guess of 10).  If a very strong El Niño develops (Niño3 anomaly of ~2°C), then the prediction will be slightly lower: 7.9 +/- 2.8 storms (range of 5-11 storms with a best guess of 8).

Using an alternative model that uses "relative" MDR SST (MDR SST with the average tropical mean SST subtracted) in place of MDR SST yields a similar prediction (8.3 +/- 2.9 total named storms).

Previous Forecasts:

Year (click to see forecast)
Prediction
Best Guess
Range
Actual Count
2007 n/a 15 n/a 15
2009 11.5 +/- 3.4 12 8-15 (6-13 if El Niño) 9
2010 23.4 +/- 4.8 23 19-28 19
2011 16.25 +/- 4.0 16 12-20 19
2012 11.2 +/- 3.3 11 8-15 19
2013 16.0 +/- 4.0 16 12-20 14

References:       
Kozar, M.E., Mann, M.E., Camargo, S.J., Kossin, J.P., Evans, J.L., 2012: Stratified statistical models of North Atlantic basin-wide and regional tropical cyclone counts, J. Geophys. Res., 117, D18103, doi:10.1029/2011JD017170.

Mann, M.E., Sabbatelli, T.A., Neu, U., 2007: Evidence for a Modest Undercount Bias in Early Historical Atlantic Tropical Cyclone Counts, Geophys. Res. Lett., 34, L22707, doi:10.1029/2007GL031781.

Sabbatelli, T.A., Mann, M.E., 2007: The Influence of Climate State Variables on Atlantic Tropical Cyclone Occurrence Rates, J. Geophys. Res., 112, D17114, doi: 10.1029/2007JD008385.

Vecchi, G.A., Knutson, T.R., 2008: On Estimates of Historical North Atlantic Tropical Cyclone Activity, J.Climate, 21, 3580-3600, doi:10.1175/2008JCLI2178.

Footnotes:

The tropical cyclone series was corrected based on an estimated historical undercount taken from Vecchi and Knutson (2008).

Prediction made: 12 May 2014

This webpage last updated: 16 May 2014