El Niño to suppress upcoming hurricane season, but Pacific storms could be more active

The National Hurricane Center and its parent organization, the National Oceanic and Atmospheric Administration (NOAA), just released this season’s hurricane outlook. The season runs from June 1 to Nov. 30.

The Pacific Northwest does not get hurricanes, but it does get hurricane-force winds from strong North Pacific storms that brush the coast or track inland. Yet for those with relatives and friends who live in hurricane-prone areas along the East and Gulf coasts, or who plan to visit these regions, this outlook can be quite important for early readiness.

The outlook focused on a better-than-50% chance of a below-normal Atlantic hurricane season, with a total of eight to 14 named storms, including one to three major hurricanes of Category 3 or higher. The average number of named storms is 14. The chance of an above-normal hurricane season was anticipated to be only 10%.

The hurricane wind scale ranges from a Category 1 with sustained winds of 74 to 95 mph, a Category 3 with sustained winds of 111 to 129 mph, and a Category 5 with sustained winds of 157 mph or higher. To give perspective, the granddaddy of all non-tropical windstorms to strike the lower 48 in American history was the 1962 Columbus Day Storm. That storm had winds of up to 150 mph along the Oregon and Washington coasts, and in excess of 100 mph in the western interior valleys from Eugene, Oregon to Vancouver, B.C.

Primary driving of the hurricane season

The primary reason for the anticipated lower number of tropical cyclones in the Atlantic is the developing El Niño in the Eastern Pacific. Despite unusually warm sea surface temperatures in the 80s along the African coast, the Gulf, and the eastern seaboard, the El Niño weather pattern tends to dampen Atlantic storms.

Tropical cyclones feed off warm waters of 80 degrees or warmer, and can rapidly intensify with unusually warm waters. Eastern Pacific tropical sea surface temperatures are expected to be quite warm, leading to more tropical cyclones in this region.

The last El Niño in the Eastern Pacific tropical waters was in 2022. In October that year, Hurricane Otis rapidly intensified from a tropical storm to a Category 5 hurricane in less than 24 hours before making landfall in Mexico, thanks to the very warm ocean waters.

Preparing

It is important to prepare in advance for any tropical cyclones. Not only do they produce strong, damaging winds, but they also bring heavy rain, flooding, and even tornadoes.

But the most important is wind-driven storm surge. Since the 1960s, more than half of all tropical storm fatalities have been due to storm-surge flooding. There are a number of major storm surge examples, but one recent and quite memorable significant event was Hurricane Katrina in 2005, which struck Louisiana and Mississippi, resulting in more than 1,300 fatalities.

Hurricane forecast track map gets a makeover

The National Hurricane Center announced a major change to the hurricane forecast track map, also known as the hurricane forecast cone.

Starting June 1, the hurricane center will use an improved version of the tropical cyclone forecast cone graphic, which has been in use since 2002. This new version will now include tropical storm and hurricane watches and warnings for inland areas for the continental U.S., Hawaii, Puerto Rico, and the U.S. Virgin Islands.

The center will also initiate testing of an experimental version of the forecast cone graphic that captures a greater range of possibilities for the storm’s track by incorporating uncertainties in both movement direction and timing.

“The goal of these new hurricane forecast track maps is to enhance improving communications about hazards and risk with the public and emergency managers,” Michael Brennan, director of the Hurricane Center, said. “That’s to better convey the wind risk, and better convey that hazards can extend outside of the cone.”

The circles on the forecast cone chart will change to ellipses since research has shown the ovals are more effective at illustrating potential forecast errors along the forecast track.

“The previous chart was one that people didn’t really understand that well,” the center’s Warning Coordination Meteorologist Robbie Berg said regarding the new experimental forecast cone chart.

Being ready for hurricane season

If you have friends and relatives in these hurricane prone regions on either side of the North American continent, they need to prepare for what this hurricane season. Or if you plan to visit these same areas this summer or early fall, know in advance of any potential incoming storms and prepare ahead of time by using the hurricane center’s full suite of hurricane forecast charts. Waiting until the storm approaches may be too late.

Ted Buehner is the KIRO Newsradio meteorologist. Follow him on X and Bluesky. Read more of his stories here.