weather forecast. Unusual, seasonal cold spells over Australia and South America, and this is why «3B Meteo

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Two regions in the Southern Hemisphere will experience temperatures well below average up to 10/15 ° C; This happens one month after the arrival of the Australian summer.

An unusual cold wave is currently occurring in South America Because of the cold air front that will bring an air mass of Antarctic origin to affect many countries. The intensity of the advection is like pushing cold air over the equator for the next few days, until it reaches the Caribbean Sea.

According to the Extreme Expectations Indicator of Ecmwf Expected temperatures are statistically significant, extremes for this period.

These are the consequences of the development of a powerful hurricane near Chile, A zone circulation mass that facilitates the entry of a very cold air mass (down to -6 sigma at about 1,500 m) from Antarctica. It’s an exceptionally cold start to November even over part of Australia, Especially in the southeast where Melbourne did not exceed 13 degrees Celsius with rain and even cold. It is the second coldest day in the past decades. Snow is expected in Victoria and New South Wales in the off-season as cold Antarctic air will reach southern Australia and Tasmania, bringing widespread rain in the coming days. Bad weather in Australia results from the collision of a mass of cold polar air with warm, humid subtropical air. The Nina and negative IOD also result in record precipitation in eastern Australia.

The southern hemisphere has often been especially cold since August. Strong cold waves have been unleashed especially in South America with temperatures 10-15°C below normal.

On the vertical plane, the stratospheric polar vortex is also very cold and compressed And it had an impact on the circulatory events in the lower classes. The cold values ​​in the stratosphere are believed to be a result of the amount of water vapor generated by the eruption of the Tonga volcano in January; But at the moment only hypotheses remain.

After this arc of increase in wave activity, in the next few days conditioning is expected by the polar stratosphere in Antarctica with a rapid rise in the AAO index. It must be said that during La Nina the chances of positive SAM indicators increase.

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