Eastern Pacific Tropical Storm Outlook

In Weather Routing Inc.’s newsletter, senior meteorologist Amanda Delaney filed this report: “We are approximately a month from the start of the Eastern Pacific Ocean Tropical Cyclone Season.” The season officially begins on May 15 and lasts through November 30. “So how active will the season be this year? Let’s see what factors play into this prediction.

“An average tropical cyclone season in the East Pacific usually yields 15-16 named tropical cyclones (tropical storm status or greater), 9 hurricanes and 4 major hurricanes (category 3 or greater).

“Tropical cyclones need several conditions in order to develop. These are sea surface temperatures of 26°C [78.8°F] or more, light winds aloft, and abundant atmosphere moisture. If these features are present or are predicted in the future, we can expect an above average season.”

“A weather phenomenon that will help determine whether it will be an above normal or below normal tropical cyclone season is: El Niño, La Niña or neutral phase occurrence through the season,” continues Delaney. “As of April 15, the status of El Niño is warm neutral. Neither El Niño or La Niña is present.

“Normal trade winds exist with cooler-than-normal sea surface temperatures found off Northwestern South America and over the Central Tropical Pacific. Squalls are present to the north of the equator over the Eastern Pacific in this pattern.

“The sea surface temperatures over the Eastern Tropical Pacific are warmer than normal (by 1-3 degrees Celsius and are at or above 26°C).
While it is likely that this neutral phase will continue through the autumn, there is a chance that a weak La Niña could develop toward late summer/early autumn.

“Given the above factors, WRI expects an above average tropical activity for the 2020 East Pacific tropical season, with an anticipated 17-20 named tropical systems.”