A scorching heat wave is to hit the Korean Peninsula beginning this week, the state weather agency said Tuesday, without ruling out the possibility of extremely hot weather due to stagnant high-pressure air masses.

The Korea Meteorological Administration (KMA) said that the seasonal monsoon period is to virtually end on the peninsula after some scattered rain showers nationwide in the day and full-scale sweltering heat will take over.

Daytime highs will rise by up to 3 C to above 35 C in many parts of the country starting Wednesday, the KMA said, noting the sensible temperatures will be higher by 1 C or more due to high humidity.

The agency predicted that the nation may be hit by a so-called heat dome phenomenon from this week, as the North Pacific high pressure and the Tibetan high pressure, both containing hot air, are forecast to meet over the peninsula.  A heat dome is a phenomenon in which high pressure stagnates in an area and acts like a pressure cooker lid to trap sweltering heat and continue to raise temperatures.

The KMA said it will issue more heat wave advisories and warnings nationwide, as temperatures are expected to rise further in the days ahead.

Residents in urban areas, in particular, will also suffer from the tropical night phenomenon, which occurs when the temperature does not fall under 25 C during the nighttime, it added.

"A scorching heat wave is to begin with the influx of the North Pacific high pressure. However, it is too early to tell whether extremely hot weather will unfold here as the Tibetan high pressure has yet to show any movement," a KMA official said.

"A sweltering heat wave will persist for the time being, but whether the heat dome phenomenon will actually occur remains to be seen due to variability linked to typhoons and other factors," the official explained. (Yonhap)