Temperatures in parts of Sydney dropped around 10 degrees in just 15 minutes after a strong southern change hit the city just before 5pm on Thursday.
The Bureau of Meteorology has issued a severe weather warning for damaging winds affecting Sydney and the Illawarra region, warning shocks above 90 km / h are possible.
Weatherzone Meteorologist Joel Pippard said NSW’s south coast also experienced “rapid temperature drops”, with mercury falling seven degrees in 10 minutes in Ulladulla earlier Thursday afternoon.
All of Sydney experienced temperatures 30 degrees and higher Thursday with gusty westerly winds keeping the temperature warm.
Just before 5pm, temperatures began to drop rapidly as the southern change reached Sydney.
At Sydney Airport, the temperature at 16.43 was 29.9, but just 15 minutes later it had dropped 10 degrees to 19.9. At Observatory Hill, the temperature dropped from 29 degrees at 16:40 to 19.5 an hour later.
“The southern change is associated with a cold front. When it comes around the corner of the southern NSW coast, it helps [the change] become stronger due to the sea breeze effect – the difference between water and land temperatures, ”said Pippard.
“It helps amplify this change, so when it arrives … when the country is at its hottest and the cool change is still just as cool, it creates a big temperature difference, a big increase in wind speed and causes a rapid temperature drop, when it actually arrives. ”
The southern change caused gusts of 94 km / h at Kiama, on the south coast.