There is a high probability of a new El Niño taking hold in the Marshall Islands and the north Pacific later this year, according to US weather forecasters. “There is a 60 percent chance of El Niño in the Northern Hemisphere in September-November, increasing to 70 percent during the winter 2018-19,” said the Pacific ENSO Update issued earlier this month by Guam weather officials who track climate conditions in US-affiliated islands.
For the Marshall Islands, an El Niño usually causes extended drought. An “El Niño watch” by weather forecasters was triggered earlier this year in response to ocean warming that indicated El Niño conditions were brewing. “Some weather features more typical of El Niño have recently occurred, including a very wet eastern Micronesia, several early season tropical disturbances in eastern Micronesia and some unusual westerly winds in eastern Micronesia,” said the report.
“From Pohnpei and eastward, conditions were mostly wetter than average (during the first six months of 2018), with rainfall amounts at Kwajalein and Majuro surging to new historical highs,” said the Guam weather report. “During July and August, the pattern of abundant rainfall in the east — RMI — continued, with persistent dryness in the far west — Palau.”
Rainfall for Majuro over the past 12 months set an all-time record high, while rain at Kwajalein from January to June was record-setting. The new 12-month and six-month records wipe out previous records dating back to when rain data first began being collected in the mid-1950s. Twelve-month periods ending in July show that Majuro broke the 200 inch level for the first-time ever this past July. Meanwhile, Kwajalein was deluged from January to June — a period that is normally a dry season. Its six-month total topped 80 inches, well above previous six-month rainfall records, according to the Pacific ENSO Update.
“The high rainfall didn’t just edge-out previous highs — it crushed the old high marks by large margins,” said the Update.
But there’s a down side to heavy rainfall in the Marshall Islands. “Very heavy rainfall in the RMI early in the year is often associated with El Niño onset,” said the Update. “However, a wet spring has also occurred…thus limiting the usefulness of this phenomenon as a predictor of El Niño.”
Still, weather forecasters see the record-setting rainfall in the RMI as a “red flag” suggesting the weather system “may soon shift to El Niño.”
The weather forecast says all of RMI will continue receiving above-average rainfall through June 2019.
Read more about this in the September 21, 2018 edition of the Marshall Islands Journal.