Northeast Pacific breaks record for its most active hurricane season
The region officially broke the record early Sunday evening
The northeastern Pacific Ocean just cracked the top spot for its most active hurricane season ever recorded.
Almost every hurricane that’s formed this year intensified into a major Category 3 storm or stronger, including three scale-topping Category 5 storms.
A record-setting El Niño is largely responsible for this hyperactive hurricane season.
DON’T MISS: ‘ACE’ is the best way to measure a hurricane season’s ferocity
A historic season with more room for growth
As of Oct. 11, we’ve seen 21 storms form throughout the eastern and central parts of the Pacific basin this season, which have caused major damage from Hawaii to Mexico.
Beyond counting the raw number of storms, forecasters measure the true intensity of a hurricane season using Accumulated Cyclone Energy (ACE).
This metric accounts for the intensity and longevity of each storm. A stronger, longer-lived storm will generate a much higher ACE value than one that’s weak and brief.
Data from Colorado State University reflects that the northeastern Pacific’s ACE value hit 318.8 as of 5:00 p.m. EDT on Sunday.
This beats the previous all-time record of 318.1 observed during the robust 2018 hurricane season. Just three storms -- Polo, Lowell, and Nolo -- have accounted for nearly half of this season’s total alone.
An average year across the northeastern Pacific basin generates an ACE value of 132.7, making this hyperactive season more than twice as active as normal.
Hurricane Simon pushed the season over the top as its high-end Category 4 winds and torrential rains brought dangerous conditions to western Mexico through the weekend.
A jaw-dropping number of powerful storms
Very warm waters and an exceptionally favourable atmosphere, both influenced by El Niño, allowed 11 of this year’s 21 storms in the northeastern Pacific to grow into hurricanes. All but two of those storms achieved major hurricane intensity.
Three hurricanes peaked as Category 5s, including Genevieve, Lowell, and Polo, the latter of which grew into the region’s second-most intense hurricane on record in terms of air pressure.
Ten storms so far have affected land, with Hawaii and Mexico taking the brunt of the damage.
Hurricanes Lala, Moke, Lowell, and Nolo all brought extensive flooding rains to Hawaii, making for one of its worst hurricane seasons on record. The airport in Hilo, on the Big Island, recorded more than 940 mm of rain betwen Aug. 1 and Sept. 30, which is more than double the average over that two-month span.
Number likely to grow as season continues
Hurricane season in both the northeastern Pacific and the Atlantic basins continues through Nov. 30.
It’s likely we’ll see additional storms in the Pacific in the days and weeks to come, which would further pad this already lofty total.
For as much as El Niño has influenced a hyperactive season on the western side of North America, that’s how much the unusually hot ocean waters have suppressed Atlantic hurricane activity.
This year’s ACE value in the Atlantic is running less than 20 per cent of normal for the middle of October. Hurricane Isaias, which recently made landfall in Florida, was the basin’s latest first hurricane on record. This year’s sluggish activity beat the previous record by more than three weeks.