How rare are April storms in the Philippines?

MANILA, Philippines (UPDATED)– The start of the dry season in the Philippines might just be a wet one.

On Tuesday, March 31, the northeast monsoon (Amihan) ended, marking the start of the dry season in the Philippines. (READ: Summer begins in PH as new storm nears)

But just as summer had started, a typhoon entered the Philippine Area of Responsibility (PAR) on Wednesday, April 1.

Located 970 km east southeast of Virac, Catanduanes, as of 5 pm Thursday, April 2, Chedeng has maximum sustained winds of 175 km/h near the center and gusts of up to 210 km/h. It is expected to make landfall in Aurora or Isabela over the weekend.

When Typhoon Chedeng entered PAR, it was categorized as super typhoon by the United States Navy’s Joint Typhoon Warning Center (JTWC). It was then downgraded by JTWC to typhoon status. 

Just how rare are storms in the Philippines during the month of April, when it’s usually the dry season?

Second least visited

For the past 67 years, there have only been 32 tropical cyclones that entered PAR in the month of April, according to data from state weather bureau Pagasa.

The first was in 1955, when Typhoon Anita cut across the northeastern corner of PAR from April 20-27. It, however, did not affect the weather in the country.

April ties with January as the second among the months least visited by tropical cyclones, next to March and February, which only had 20 storms each since 1948. July is the month most visited by storms with 222 storms as of posting. (READ: How frequent are storms in PH in March?)

According to Pagasa’s data, among the tropical cyclones in April, typhoons were the ones that mostly visited the country. Out of 32 tropical cyclones, 16 of them were classified as typhoons. (READ: Weather 101: Tropical storm vs Super Typhoon)

The last devastating typhoon that struck the country in April was 21 years ago, when Typhoon Bising (Owen) crossed Visayas in 1994. It caused around P358 million worth of damage and killed about 11 people.

Meanwhile, for the last 20 years, there have only been 12 storms that entered the PH, with majority recurving to the Pacific Ocean.

Devastating storms

While not all of them were typhoons, some caused considerable to heavy damage to affected areas and left a number of people dead as they made landfall. Among the 16 tropical cyclones that made landfall, 8 of them brought damage to crops and property and casualty to the country.

1. Typhoon Karen, April 20-26, 1960

– maximum wind speed of 65 km/h at Surigao, passing through northeastern Mindanao, southern and western Visayas

– left considerable damage and several lives lost

2. Typhoon Karing (Violet), April 4-12, 1967

– maximum wind speed of 169 km/h in Tuguegarao

– 3 dead; with considerable damage to property

3. Typhoon Atring (Susan), April 20-24, 1969

– maximum wind speed of 111 km/h in Surigao

– 24 dead; with P15,000 worth of damage to crops and property

4. Tropical Storm Diding (Wanda), April 23-28, 1971

– maximum wind speed of 160 km/h in Tacloban

– 56 dead, 39 missing; P4.3 million in damage

5. Typhoon Atang, April 18-27, 1978

– one of the most devastating typhoons of 1978, with maximum wind speed of 180 km/h, in Romblon; crossed Guian, Samar, north of Tacloban, Masbate, and Romblon; went out of PAR but re-entered and passed through north of Itbayat, Batanes. 

– 66 dead, 45 missing, 47 injured; P245 million in damage

6. Typhoon Bebeng, April 12-20, 1979

– maximum wind speed of 180 km/h in Recon and Tacloban; passed through Tacloban, Leyte, Masbate, and Romblon; recurved then passed through southern Quezon and Camarines Norte.

– 30 dead; 63 missing, 73 injured; P267,188,074 in damage

7. Tropical Depression Bining, April 12-13, 1993

– maximum wind speed of 45 km/h; passed through Agusan del Sur and Misamis Oriental.

– 3 dead; more than P4 million in damage

8. Typhoon Bising (Owen), April 1-9, 1994

– maximum wind speed of 175 km/h in Maasin; crossed Southern Leyte, northern Cebu, northern Negros, southern Panay, and northern Palawan. 

– 11 dead; 7 missing; 20 injured; P357, 921,000 in damage

What are the chances?

While storms in the Philippines during the month of April are still possible, the chances are low.

“From January to April, the probability of tropical cyclone occurrences is low – .40. While for the rest of the [year], it’s 1.0. That’s up to December already,” Vic Manalo, senior forecaster from Pagasa, said.

Manalo said among the factors that contribute to typhoons rarely forming in those months are the northeast monsoon (amihan) and the sea surface temperature.

“We have what we called the “amihan” and sea surface temperatures, which is still low during this time [of the year]. The [sea] water is still cold during April,” Manalo explained. 

Meanwhile, Michael Padua, science research specialist from Weather Philippines, also said that storms are still possible even if the dry season has started.

What is rather unusual, he said, is this year’s super typhoon in the month of April.

“It has a cycle. After about 30-50 years, you’ll see that is the trend. That’s the average,” Padua said.

Manalo also said that once a typhoon enters PAR in April, it usually weakens as it makes landfall.

“Usually, systems during [the month of] April recurve, or the weak ones make landfall in the Visayas and Mindanao.” Padua added.

Most people are wondering why there is a typhoon even if the state weather bureau declared the onset of El Niño in the country in March. (READ: El Niño sets in; PAGASA warns of ‘erratic’ typhoon season)

“Based on our historical records, we would see that although there was an El Niño, we were still able to record strong typhoons. In short, El Niño does not affect the intensity of tropical cyclones that enter the country…. We don’t see El Niño as a contributing factor to the super typhoon [that we have now],” Manalo explained.

Typhoon Maysak ranks 3rd in strength among the super typhoons that occured in the months of January-April, next to Super Typhoon Ophelia (January 1958) and Super Typhoon Mitag (March 2002), Manalo said. – Rappler.com