NOAA & UK Met Office join forecasts for “extraordinary” hurricane season

The US weather service NOAA and the UK’s Met Office have both issued forecasts that join others in suggesting the 2024 Atlantic hurricane season will be a very active one, with each opting for storm numbers well above the average and NOAA saying it looks likely to be an “extraordinary” year.

The UK Met Office’s forecast actually came out yesterday, but we waited for NOAA’s announcement, made just now, to provide the two forecasts together for our readers.

Like every other forecaster of tropical storm and hurricane activity in the Atlantic basin for 2024, the pair are expecting the tropics to be particularly active this year.

The UK’s Met Office said that it forecasts the most likely number of named tropical storms for the 2024 season in the Atlantic will be 22, giving a 70% chance that the number will be from 16 to 28, above the 1991-2020 long-term average of 14.

The UK Met Office forecasts the most likely number of hurricanes this season will be 12, giving a 70% chance that the number will be in the range 8 to 16, again well above the 1991-2020 long-term average of 7.

On major hurricanes, the UK Met Office forecasts 4 for this season, saying there is a 70% chance the number will be in the range 2 to 6, again over the 1991-2020 long-term average of 3.

Finally, the UK Met Office predicts an ACE index of 212, with a 70% chance ACE will be between 131 and 293, above the 1991-2020 average of 121.

The US weather service NOAA has just announced its figures and again they are pointing to a good deal of activity in the Atlantic tropics this hurricane season, 85% above normal activity being the prediction.

NOAA is predicting between 17 and 25 named tropical storms, between 8 and 13 hurricanes and 4 to 7 major hurricanes, with ACE in a range from 150% to 245% of norm.

Notably, NOAA executives said today that this forecast is the highest number of named storms, hurricanes and major hurricanes that the agency has ever given in its May forecast.

The forecast for ACE index is the second highest ever given for a May forecast by NOAA.

NOAA Administrator Rick Spinrad warned that “this season is looking to be an extraordinary one.”

Overall, NOAA is forecasting an 85% chance of an above normal 2024 hurricane season in the Atlantic, with just a 10% chance of activity being near-normal and 5% it could be below normal.

Incorporating these latest forecast figures from the UK Met Office and NOAA, alongside the others we track, takes our Artemis Average forecast for the 2024 hurricane season, to 23 named storms, 12 hurricanes, 5 major hurricanes, with a seasonal ACE Index score of 217.

Hurricane seasons official start date is June 1st and ocean heat content levels in the main development region (MDR) are said to remain well above the norm, while Atlantic SST’s overall are slightly above average, having cooled off in some areas.

Many were expecting the warm waters would kick hurricane season off early, but now meteorologists are pointing to conditions that are seen as largely not conducive to storm formation, as well as some wind shear being evident, which could keep the Atlantic tropics quiet for another week or two.

Meanwhile, expectations that La Nina will form during the season have moderated slightly and while there is still seen to be a chance of this occurring, it could prove to be a little later than originally anticipated, which can also have a bearing as to how conducive conditions in the Atlantic tropics are for tropical storm development.

Although, perhaps notably, the UK Met Office still said yesterday that, “There is a strong signal in our forecast for La Niña to develop and persist through the peak of the Atlantic hurricane season (August to October 2024).”

They added, “When combined with a forecast of continued warmer than average sea-surface temperatures in the tropical North Atlantic, conditions appear very favourable for most likely well above average tropical storm activity in the North Atlantic, as seen in the 2024 forecast.”

With this official US government outlook, Rick Spinrad of NOAA also highlighted the forecast for a 77% chance of La Nina in the August to October time frame, as well as saying that modelling still predicts above average SST’s for that period as well.

But with waters still plenty warm enough, as and when conditions do become more favourable to storm formation, we should certainly expect a busy season still, although as ever it’s worth mentioning that it is only strong landfalling hurricanes that hit areas of significant coastal exposure concentration that really trouble the reinsurance, catastrophe bond and insurance-linked securities (ILS) markets.

Track the 2024 Atlantic tropical storm and hurricane season on our dedicated page and we’ll update you as new information emerges.