Real Climate Records

Reason We Get Them

It is possible that Perth will swelter beneath another heat wave by the week end.

This disheartening prophecy was ventured by an official at the Commonwealth Meteorological Department this morning.

Asked to define just exactly what a heat wave is and why, this official remarked with a smile that; there were probably very few people who failed to recognise one when they met it. As a rule, however, everyone is content to take a heat wave for granted and leave it at that. What makes it come is usually regarded as a matter of considerable insignificance compared with the fact that it is here.

“Generally speaking, a heat wave occurs,” explained the weather expert, “when pressure lines run from north to south. As the wind always blows along pressure lines a north to south disposition will always give north or south winds according to relative points of higher and lower pressures.”

“If the higher pressures are inland the winds will be northerly. Therefore blowing from tropics to temperate regions. If, on the other hand, the higher pressures are out to sea, the winds will be southerly, taking their origin from the cool Southern Ocean.”

And that is the scientific explanation of why our collars stick to our necks and all the other super-summer discomforts which we are called upon to endure at this time of the year.