CEBU is set to experience a high heat index until the first week of October 2019, according to the state weather bureau.
This is caused by the prevalence of easterly winds, a change of wind direction that signifies that the southwest monsoon (Habagat) is transitioning to northeast monsoon (Amihan) that will bring mild temperatures and little or no rainfall.
The Amihan period in the Philippines often starts around November or December, and ends sometime in May or June. The other months are Habagat season.
Weather specialist Jhomar Eclarino said Cebu experienced its hottest day on Friday, Sept. 27, after the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) Visayas bureau based in Lapu-Lapu City recorded a heat index of 41 degrees Celsius.
“The main reason we are experiencing a hot weather condition is the easterlies. The characteristics of the air brought by the easterlies is ‘warm and moist.’ We normally experience this during the transition period,” he said. “The temperature is expected to cool down when Amihan finally dominates the country’s weather system by November.”
The heat index, according to Pagasa, is a human discomfort index perceived by humans as the temperature affecting the body.
According to Eclarino, when the heat index reaches 40 to 41 degrees Celsius, it already falls under the “extreme caution” category.
“It’s already under the ‘extreme caution’ category as it could possibly trigger heat cramps and heat stress. Should there be continuous activities outside, directly to sunlight, it could possibly trigger heat stroke,” he said.
He then advised the public to properly hydrate themselves and to stay indoors as much as possible.
“We have to avoid direct exposure to sunlight from 10 a.m until 3 p.m. because it’s within that time that we can record the maximum temperature and the maximum heat index. It is advisable to wear lightly colored and comfortable clothes. Remember to properly hydrate yourself, and to continuously monitor weather advisories,” he said.
Other areas in Central Visayas, outside of Cebu, also had the heat index of 39-40 degrees Celsius on Friday, he added.
As of September this year, the lowest heat index recorded in Cebu was at 35 degrees Celsius.
There are two factors affecting the heat index, the weather bureau said.
These are the (maximum) air temperature and the relative humidity (or the amount of moisture in the atmosphere).
High air temperatures and high relative humidity will give high apparent temperatures or indices.
“As of 12:25 p.m. Friday, our maximum air temperature is 34.3 degrees Celsius, while the relative humidity is 53 percent,” Eclarino said.
Meanwhile, a tropical depression (TD) is also expected to enter the Philippine Area of Responsibility (PAR) on Saturday, Sept. 28.
Eclarino said once it enters PAR, it will be named TD Onyok, the fifth tropical depression to enter the country for the month of September. As of 3 p.m. Friday, it was seen at 1,410 kilometers east of Visayas.
“Basing from its track, there is no chance that it could make landfall in the country. It does not pull the southwest monsoon that much. That is why the rains experienced here in the Visayas are isolated. What’s critical are the thunderstorms because these localized thunderstorms could bring moderate to heavy rains in some parts of the region,” he said.
Onyok is expected to be out of PAR by Tuesday, Oct. 1. (WBS)