Government Forecasters Issue their Highest Hurricane Season Outlook to Date

“This season is looking to be an extraordinary one” says NOAA's administrator

2024 hurricane season outlooks from Colorado State University (issued April 4^th) and NOAA (issued May 23^rd). The seasonal predictions from both groups are the highest ever issued since pre-season outlooks began in 1995 (CSU) and 1999 (NOAA).

On Thursday, government forecasters – including senior forecasters from the National Hurricane Center – issued their highest predictions headed into a hurricane season since federal hurricane outlooks began in 1999.

The team of scientists at NOAA, the parent agency of the National Weather Service, predicts an 85% chance of an above-average Atlantic hurricane season in 2024, with 17-25 named storms and 8-13 hurricanes, with 4-7 becoming Category 3, 4, or 5 hurricanes. The 30-year (1991-2020) seasonal averages are 14 named storms, 7 hurricanes, and 3 Category 3 or stronger hurricanes.

Regarding their aggressive predictions, NOAA Administrator Dr. Rick Spinrad commented, “This season is looking to be an extraordinary one in a number of ways.”

The strong outlook from NOAA follows similarly bullish forecasts from other groups, such as Colorado State University, which issued its highest seasonal predictions to date back in early April.

Record warmth paired with a looming La Niña

NOAA’s forecast comes as tropical Atlantic waters reach all-time records for the time of year. As of this week, 92% of the Main Development Region of the Atlantic – where 85% of Category 3, 4, and 5 hurricanes form – is at record or near-record seasonal warmth.

Top 5 warmest and coldest sea surface temperature anomalies for the week ending May 22^nd (based on the 1981-2024 period of record). Over 90% of the Atlantic Main Development Region (black box) is at record (deep red) or near record (light red) levels for the time of year.

The astonishing heat blanketing the entire hurricane belt is forecast to continue into August, September, and October – the peak months of the hurricane season. Government forecasters note high sea surface temperatures favor rapid intensification episodes and major hurricane development, which contribute to high accumulated cyclone energy or ACE, a scorecard of hurricane season activity. NOAA expects an ACE of 1.5 to 2.5 times the average, a forecast second only to their 2010 ACE predictions.

Perhaps the biggest wildcard this hurricane season is the anticipated arrival of La Niña by late summer or early fall. The potent El Niño of 2023 is quickly becoming a distant memory and NOAA is forecasting a near 80% chance of La Niña conditions – a cooling of the waters around the equator in the eastern Pacific – as hurricane season hits its stride this fall.

Probability of La Niña conditions (blue bar), neutral (gray bar), or El Niño (red bar) conditions for each three-month period into 2025 from NOAA. NOAA is forecasting a 77% chance of La Niña conditions by August-September-October (ASO) 2024, the peak months of hurricane season. Credit: Columbia Climate School International Research Institute (IRI).

La Niña conditions tend to reduce disruptive wind shear in the Atlantic, which can tear at organizing hurricanes. The reduction in shear from La Niña is typically most pronounced in the western part of the Atlantic and Caribbean, which could favor storm development closer to land areas, including the mainland U.S., in 2024.

A reason to be concerned, but not alarmed

National Weather Service Director Ken Graham noted the eye-catching seasonal hurricane outlook issued Thursday was “a reason to be concerned, but not alarmed.” Pre-season hurricane outlooks can’t tell us where or when a hurricane might strike – we can’t accurately forecast short-term weather conditions this far out – and it only takes one bad hurricane to make a bad hurricane season, regardless of the overall numbers.

Graham reminded coastal residents that every Category 5 hurricane that made landfall in the U.S. in the past 100 years was a tropical storm or weaker only three days before landfall. “These storms don’t care about your timelines,” he noted, making now – and before a storm threatens – the best time to prepare.

Category 5 hurricanes making landfall on the mainland U.S. All were only tropical storms or weaker 3 days prior to making landfall. Credit: Brian McNoldy/University of Miami.

As Florida readies for the upcoming hurricane season, the state is offering multiple two-week sales tax holidays this summer to eliminate the tax burden on disaster preparedness items. The first such sales tax holiday will extend from June 1^st to June 14^th. A list of disaster preparedness items that qualify can be found here.

Mostly quiet for now in the Atlantic

The National Hurricane Center Thursday morning was highlighting an area of storminess extending from the central Caribbean into the southwestern Atlantic.

This disturbed weather is being produced by a nearby jet stream dip interacting with a broad area of low pressure. The presence of strong nearby jet stream winds and dry air wrapping in from the west will limit development odds. There’s a small window for subtropical development in the coming days as the low-pressure area moves into the central Atlantic and away from the islands.

Regardless, the main threat will be the possibility of flooding rains and mudslides from Haiti and the Dominican Republic to Puerto Rico and the U.S. Virgin Islands into early next week.  

We’ll recommence daily newsletter updates through hurricane season beginning next Friday, May 31st.