2020 Forecast – Hyperactive Atlantic Hurricane season

hyperactive Atlantic hurricane season

Penn State University issues a Hurricane Season forecast at about this time each year. the 2020 Forecast is now available.

You will find their 2020 Forecast here.

It is worth paying attention to it. Their forecast is for a rather large number of Hurricanes in just the Atlantic.

It is the largest number they have ever predicted.

What is the 2020 Forecast?

The prediction is for 19.8 +/- 4.4 total named tropical cyclones, which corresponds to a range between 15 and 24 storms, with a best estimate of 20 named storms.

Who worked on this Forecast?

ESSC scientists Dr. Michael E. Mann and Daniel J. Brouillette and alumnus Dr. Michael Kozar.

This is their seasonal prediction for the 2020 North Atlantic hurricane season. That season officially starts on 1 June and runs through 30 November.

How exactly did they create this Forecast?

Their 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.

The assumptions behind this forecast are (a) the persistence of current North Atlantic Main Development Region (MDR) sea surface temperature (SST) anomalies (+1.1 °C in early to mid-April 2020 from NOAA’s Coral Reef Watch) throughout the 2020 hurricane season, (b) the development of mild El Niño-Southern Oscillation (ENSO)-negative conditions by boreal late summer and early fall 2020 (ENSO forecasts here; we used mid-April 2020), and (c) climatological mean conditions for the North Atlantic Oscillation in boreal fall/winter 2020-2021.

If no La Niña develops, then the prediction will be slightly lower: 18.3 +/- 4.3 storms (range of 14-23 storms, with a best guess of 19). 

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 considerably lower prediction (13.6 +/- 3.7 total named storms). This alternative model also includes mild ENSO-negative conditions.

How Accurate has their Forecast been in Previous years?

They have been issuing this since 2007, so we can look back to compare the forecast and see how well they did.

Previous Forecasts:

Year (click to see forecast)PredictionBest GuessRangeActual Count
200911.5 +/- 3.4128-15 (6-13 if El Niño)9
201023.4 +/- 4.82319-2819
201116.25 +/- 4.01612-2019
201211.2 +/- 3.3118-1519
201316.0 +/- 4.01612-2014
20149.3 +/- 3.096-128
20156.9 +/- 2.674-1011
201618.9 +/- 4.41914-2415
201715.3 +/- 3.91511-2017
201810.2 +/- 3.2107-1315
201910.1 +/- 3.2107-1318

Climate Change?

There are of course seasonal variations. However, the reality of the world we live in is that Hurricanes are basically driven by heat from the ocean. In a warming world heating up the ocean has a rather predictable result.

Hurricanes – Further Reading

here are a few of my previous postings …

Hurricane Forecast – Tweets

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