70% chance of below normal hurricane season in 2015: NOAA

The U.S. NOAA’s Climate Prediction Center released its official May forecast for the 2015 Atlantic tropical storm & hurricane season today, predicting a 70% chance of a below normal season and citing the potential for El Niño to suppress activity this year.

For the 2015 hurricane season NOAA forecasts a 70% likelihood that there will be between 6 and 11 named tropical storms with wind speeds of 39 mph or higher. Between 3 and 6 of these storms could develop into hurricanes, with winds of 74 mph or higher, while between 0 and 2 could become major hurricanes of Category 3, 4 or 5 with winds of 111 mph or higher.

Adding this forecast into our average, from the group of forecasters we track, gives an average prediction for 2015 so far of 9.58 named storms, 4.92 hurricanes and 1.58 major hurricanes for the season. The NOAA forecast has lowered the average slightly for all strengths of storm.

The NOAA place a 70% chance on 2015 turning into a below-normal season, while it gives a 20% chance of a near-normal season, and a 10% chance of it defying the forecasts and becoming an above-normal season for hurricane activity.

NOAA Administrator Kathryn Sullivan, Ph.D., warned that a low forecast doesn’t necessarily mean a low impact season; “A below-normal season doesn’t mean we’re off the hook. As we’ve seen before, below-normal seasons can still produce catastrophic impacts to communities,”  she explained, referring to 1992 when only seven named storms formed, yet the first was Andrew the Category 5 hurricane that devastated South Florida.

“The main factor expected to suppress the hurricane season this year is El Niño, which is already affecting wind and pressure patterns, and is forecast to last through the hurricane season,” commented Gerry Bell, Ph.D., the lead seasonal hurricane forecaster with NOAA’s Climate Prediction Center. “El Niño may also intensify as the season progresses, and is expected to have its greatest influence during the peak months of the season. We also expect sea surface temperatures in the tropical Atlantic to be close to normal, whereas warmer waters would have supported storm development.”

The prediction published today includes Tropical Storm Ana, but the NOAA notes that its early development should not be considered an indicator of the overall season strength.

While the Atlantic is predicted to be quieter than normal, the Eastern Pacific and Central Pacific basins are both forecast to see above average activity in the 2015 season.

The NOAA expects the Eastern Pacific hurricane basin will have a 70% percent chance of an above-normal hurricane season, with a 70% probability of 15 to 22 named storms, 7 to 12 of which are expected to become hurricanes, including 5 to 8 major hurricanes. For the Central Pacific hurricane basin, NOAA predicts a 70% chance of an above-normal season with between 5 and 8 tropical cyclones likely.

Of course, seasonal forecasts do not change the view of risk for the insurance, reinsurance, catastrophe bond and ILS markets, that is set by scientific understanding and the use of risk models. While the chances of storms forming may be considered lower through this season, the risk that one storm develops sufficiently and takes a track towards the U.S. coastline, or other insured areas, remains.

The NOAA outlook is aligned with other forecasters in calling for a below average Atlantic hurricane season in 2015. Keep an eye on the tropics as the season develops, with Artemis’ 2015 Atlantic Tropical Storm & Hurricane Season page.