Hail and thunderstorms possible over Manila today – PAGASA

State weather forecasters on Monday warned residents in Metro Manila of possible hail, or bits of ice, that may fall during thunderstorms within the day.

 

PAGASA forecaster Alvin Pura made the warning on Monday, as the state weather bureau warned of another thunderstorm over Metro Manila in the next 12 hours.

 

"Baka may mga hailstorm. Ang iba malaking patak ng tubig, ibig sabihin natunaw ang yelo," Pura said in an interview on dzBB radio.

 

He advised residents to bring their umbrellas especially if they go out in the afternoon or evening.

 

Pura also advised those with Internet access to check the PAGASA account @dost_pagasa for updates.

 

"Sundan ang aming Twitter account, doon maaring balaan kung may thunderstorm (Just follow our Twitter account for updates and warnings on thunderstorms)," he said.

 

Thunderstorms had brought heavy rain over Metro Manila since Friday. On Sunday, thunderstorms brought floods that affected at least 300 residents in Quezon City.

 

The US-based University Corporation for Atmosphierc Research, a consortium of 100 member university and academic affiliates in resarch and training in atmospheric and related Earth system sciences, said hail is formed in huge cumulonimbus clouds or thunderheads.

 

It said that when the sun heats the ground during the day, the air close to the ground is heated, and the hot air rises and cools.

 

When the warm air cooled so much it cannot retain its moisture, water vapor condenses, forming puffy-looking clouds, "and the condensing moisture releases heat of its own into the surrounding air, causing the air to rise faster and give up even more moisture."

 

"At temperatures higher than -40 degrees Celsius, a supercooled water drop needs something on which to freeze, or it remains liquid. Ice crystals, frozen raindrops, dust, and salt from the ocean are also present in the cloud. On collision, supercooled water will freeze onto any of these hosts, creating new hailstones or enlarging those that already exist," it said (http://www.ucar.edu/communications/factsheets/Hail.html).

 

Thunderstorm may affect NCR, Rizal

 

PAGASA earlier issued a 10 a.m. advisory warning of possible thunderstorms over Metro Manila in the next 12 hours.

 

In an 11:50 a.m. advisory, it also warned of a possible thunderstorm affecting Antipolo, Cainta, Angono, Taytay and Antipolo City within the next two hours.

 

"All are advised to take precautionary measures against heavy rains, strong gusty winds, lightning and possible flash floods. Keep monitoring for updates," it said. — TJD, GMA News