Saturday, January 19, 2013

Topsy Turvy Weather In Australia

You may think Philly's weather is fickle and at times odd...March 2007's roller coaster (from 80 to sleet storm in 48 hours) is my favorite example of Phickle Philly weather but Sydney may, just may, top that given what went down there in the middle of their summer.

As you may be aware, Australia has been gripped by drought over the past few months and has also been gripped by occasional bouts of extreme heat as temperatures have soared over 115 degrees on various occasions in parts of the country due to the slow arrival of their summer monsoons in the Outback. This has allowed for occasional "heat burst" events throughout the coastal cities, like Sydney and Melbourne.

Sydney's weather, in particular, has been incredibly off the wall over the past few days. Thursday's high in Sydney was only in the middle 80's, which is seasonably warm for Sydney in the midst of their summer as their average high is around 80 degrees in mid July.  However, a stronger cold front approached them from the south (remember, Southern Hemisphere weather is flipped and cold air comes in from the south) on Friday and resulted in a decent northwest wind off of the drought-parched hills to the city's west.

The result was an all-time record of 114 degrees in Sydney on Friday afternoon.  You can see that spike in temperature outlined on the graph above.  Temperatures bounced 40 degrees in about a six hour window thanks to downsloping off of the hills, plenty of sunshine, and dry them the warmest day on record.

Until that cold front came barreling through Friday evening.  Thunderstorms popped through the city during the evening hours, bringing not only relief but flipping the wind to a screaming south wind off of the Pacific Ocean.  You can see the outline of the winds kicking in during the evening hours below.  When the wind shift kicked through around 7:30 PM, temperatures began to free fall as the cold front blew through.  Temperatures dropped 18 degrees in 35 minutes.  Winds from the south gusted to 50 mph and were sustained to 40 mph, helping bring natural air conditioning in.

Chart of temperatures, dewpoint, and wind (metric) in Sydney, Australia on Friday

Over the course of Thursday, Friday, and Saturday, Sydney's highs went from 84 to 114 to 74.  Despite the heat being "dry" as dew points were in the 40's, such temperatures are still atrociously hot regardless of location...let alone a place that goes through a proverbial rollercoaster of temperature hell in a three day period of time.