El Niño-linked high ocean temps cause early rainfall, super typhoon entry— Pagasa
IMPACT ON US OUTPOST Video grabs show the damage caused by high winds and precipitation a day after super typhoon Mawar passed over Tumon Bay, Guam, on May 25, 2023. Mawar passed just north of the US territory of Guam on Wednesday, the island’s governor said, bringing destructive winds to the Pacific military outpost. — Photos by AFP
MANILA, Philippines —State meteorologists said Friday that high oceanic water temperatures in the Pacific, commonly linked with an El Niño-Southern Oscillation phase, caused early rainfall and the entry of a super typhoon at this time of year.
In a press briefing on Super Typhoon Mawar, Dr. Esperanza Cayanan of Pagasa discussed if the early rainy season and Mawar could impact El Niño predictions.
Pagasa had predicted an 80% possibility of El Niño season between June and August 2023 and a 41% chance of more significant ocean surface warming later in the year.
READ: Pagasa: PH has 41% chance to experience ‘strong’ El Niño this year
In response, Cayanan stressed El Niño also influences the rainy season by enhancing the southwest monsoon or habagat, as higher ocean surface temperatures are conducive to forming cloud bands and, eventually, stronger tropical cyclones.
READ: El Niño may bring more rain to western part of PH during habagat season – Pagasa
“What we are saying about the onset of the rainy season, the relationship of El Niño based on our observation, is that if we have an El Niño, it enhances our habagat. That’s why we expect higher than normal rainfall. So, at the onset of our rainy season, we think it would be next week and that we would have higher rainfall by June-July and even August, because that’s when we would feel El Niño,” she said in Filipino.
“We would have more or above normal rainfall, particularly because of the enhanced habagat. So that’s the relationship. If we have an El Niño but we still have strong rains, this is what researchers call a reversal — we have rains first before we experience a water shortage towards the latter part of this quarter, which is now the impact of El Niño,” she explained.
Pagasa’s latest weather bulletin on Mawar — which would be named “Betty” once it enters the Philippine area of responsibility (PAR) — showed that as of Friday afternoon (May 26, 2023), the cyclone is still packing maximum sustained winds of 215 kilometers per hour (kph) near the center, and gustiness of up to 260 kph.
It was last seen 1,705 kilometers east of southeastern Luzon, moving west at 20 kph.
While Mawar is expected to weaken when it enters PAR gradually, it is rare for the Philippines to experience super typhoons in May.
When Haiyan or Super Typhoon Yolanda struck the eastern Philippines with maximum sustained winds of over 220 kilometers per hour (kph), it happened in November.
READ: One of world’s strongest typhoons lashes Philippines
Recent super typhoons also hit the country during the same timeframe:
Super Typhoon Rolly hit eastern Luzon during the latter part of October 2020.
Super Typhoon Odette hit the eastern side of the country a year after, particularly in December.
READ: ‘Rolly’ nearing super typhoon category, seen growing more powerful
READ: Odette: Impact on PH described as ‘catastrophic’
When asked if climate change plays a part in stronger cyclones, Cayanan said that evidence shows higher air temperatures contribute to more severe weather events.
“Based on our observations, there really is evidence that our air temperature is higher, so the temperature of our environment rises also and if seas are hotter, there would be more available energy, more water to evaporate and condense as clouds — more energy available for the development and intensification of tropical cyclones,” Cayanan said.
“So we could maybe relate that if the water surface temperature is higher, then we could see the formation of stronger cyclones. So that — higher temperatures — could contribute,” she added.
Earlier, Pagasa meteorologists have urged Filipinos not to be complacent just because Mawar is expected to weaken once it enters PAR, as it would still be a typhoon-category cyclone.
Cayanan said in the same briefing that Mawar would not hit the country like Super Typhoon Yolanda did. However, she urged the public not to think of it as weak, as it can still carry strong gusts of winds.
READ: Super Typhoon Mawar even stronger as it gets nearer to PAR border
