While the country has been experiencing longer nights since the autumnal equinox last month, it will still take some time before markedly colder nights can be felt throughout the archipelago.
In its latest climate outlook covering the period Oct. 2017 through March 2018, the Philippine Atmospheric Geophysical and Astronomical Services Administration (Pagasa) forecasts “slightly warmer than average surface temperature” in most areas of the country for the remainder of 2017.
For sure, cold surges and “slightly cooler than average” temperatures are expected, but these will be mostly felt in the mountainous areas of Luzon, and only starting 2018, according to the climate outlook.
Pagasa weather forecaster Sheila Reyes said as much in a recent phone interview with the Inquirer.
Reyes explained that cold temperatures presently being experienced in some areas in the country were most likely due to effects of prevailing weather systems this month, namely: intertropical convergence zone (ITCZ), thunderstorms, low pressure areas (LPA), ridge of high pressure areas, easterlies, tail-end of a cold front, and transition from the southwest monsoon (habagat) to the northeast monsoon
season (amihan).
One to two tropical cyclones are expected to hit the country this month, though none of the low pressure areas that have developed or entered the Philippine area of responsibility has intensified thus far, Reyes said.
The LPAs are also not associated with the northeast monsoon, she added.
She said that the onset of the northeast monsoon, or cold winds from the northeast, should be expected by the latter part of the month or early November.
The Philippines has been experiencing longer nights since the autumnal equinox last Sept. 23.
During the equinox, which occurs twice annually, day and night are of approximately equal duration across the world.
After the autumnal equinox, Pagasa said “Philippine nights will be longer as the sun moves below the celestial equator toward the southern hemisphere.”