Q&A – What Is an Average Hurricane Season & How Often Has NOAA Predicted One? – Driven By Braman Motorcars
Each day I feature a listener question sent by one of these methods.
Email: brianmudd@iheartmedia.com
Social: @brianmuddradio
iHeartRadio: Use the Talkback feature – the microphone button on our station page in the iHeart app.
Today’s Entry: Today’s note was submitted via talkback asking about whether NOAA was hyping hurricane season with above-average reporting expected.
Bottom Line: At the onset of this year’s hurricane season, which thankfully remains free of any activity, I've continued to receive many inquires like today’s, about forecasting methodology and accuracy. As I addressed prior to hurricane season, NOAA’s preseason forecasting has proven to be the most accurate as they’ve correctly called two of the previous five hurricane seasons within their preseason activity range (all other preseason forecasters have missed total activity each of the previous five seasons). But still, that’s only 40% success in recent predictions. So, about today’s question. Is there potentially an implicit bias to project above average hurricane seasons in the era of climate change hysteria by many?
Since the advent of satellite technology in 1966, the average number of named storms during the Atlantic hurricane season is 14. Often forecasters will look at 30-year trends to define what an average season is. Over the most recent 30-years, the average number of named storms per season has been 15. This analysis shows that the trend has been towards more activity but only by an average of one extra named storm per season on average compared to the historical norms. So before diving into a deeper dive into NOAA’s preseason forecasting tendencies, let’s look at how many hurricane seasons have been average to below average since the advent of NOAA’s preseason hurricane forecasting starting with their first preseason forecast in 1999.
- 14 average- to- below average seasons with 12 above average seasons.
What has NOAA projected over that same time frame?
- 16 above average seasons compared to 10 average or below average seasons
It’s worth noting that NOAA always offers up a probability of outcomes rather than saying definitively that a season will be above or below average. For example, NOAA’s preseason forecast for this season, predicted a 60% chance of an above-normal season, a 30% chance of a near-normal season and a 10% chance of a below-normal season. So yes, on balance it’s an above average forecast; however, they’re saying it’s a 60-40 type of proposition this season.
NOAA’s preseason forecast has generally aligned with the level of activity 86% of the time. That’s a really strong performance. In other words, NOAA hasn’t just been the most accurate hurricane forecaster in recent years; they’ve consistently provided accurate guidance regarding the level of activity heading into hurricane season.
It’s possible that the perception of hyped hurricane seasons is due to the other preseason forecasts that’ve proven to be less accurate and have used sensational verbiage as well.
This hurricane season has started out somewhat similarly to last year’s hurricane season with Saharan dust in the air, no preseason activity and no activity during the first half of June. The first named storm last year, Tropical Storm Alberto, developed on June 19th. This year’s forecasting has essentially called for a similar season to last year’s hurricane season. June 19th is the first benchmark to check off to see if we’ll potentially track towards less activity than last year’s above average season. That National Hurricane Center isn’t projecting any activity for the next seven days, which takes us at least until the 17th and more Saharan dust is in the air making its way across the Atlantic right now. Fingers crossed...