Climate Outlook

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Issue_32_December_2018-6

Every fortnight the Bureau of Meteorology (BOM) publishes climate outlooks for the next few months. These can be handy when planning longer trips or if you have a busy month of bushwalking coming up it can help give you a sense of what the temperate and rainfall trends are likely to be.

Climate Outlook December 2018 - January 2019

6 | BWA December 2018

Climate outlook vs weather forecastsA weather forecast is generally reliable for the next few days or week and gives you a sense of the likely specific temperature minimums, maximums as well as home much rain you can expect on each day. Climate data is not a forecast, rather is the average or typical weather patterns for an area over recent history. Climate information has the average minimum temperatures, average maximums temperatures and rainfall for a period of time, giving a sense of what we can typically generally expect.

This Climate outlook is actually a forecast that gives us a sense of how much to expect the weather to deviate from these normal climate conditions. It gives us the probability of it being hotter/colder or wetter/drier than normal for specific areas.

The BOM provides more details on their climate outlook pages including the significant influences on their models that impacted on the forcast, such as El Niño. These are generally sea temperature related, but we will not go into the details in these summaries.

Temperature outlook for December to FebruaryGenerally, we are looking at a warmer than typical summer days and nights for Australia.

Days are very likely to be warmer than average for most of Australia. Chances of a warmer summer are greater than 80% over of Australia, with lower chances for southern and western coastal areas closer to 70%.

Nights are also very likely to be warmer than average across most of Australia, with chances of warmer nights exceeding 80% over most of the country. Far western WA is really the only area that is more likely to have cooler than average summer nights.

Chance of exceeding the December maximum temperature

Chance of exceeding the January maximum temperature

Chance of exceeding the December minimum temperature

Chance of exceeding the January minimum temperature

Chance of exceeding median maximum temperature (%)

Chance of exceeding median minimum temperature (%)

BWA December 2018 | 7

You can watch the BOM video here.

Rainfall outlook for December to FebruaryGenerally, for most of southern and eastern Australia, there is a roughly equal chance of wetter or drier three months.

However, it is likely to be drier than average for large parts of Western Australia, Queensland and the Top End of the Northern Territory. For the remainder of the country, there are roughly equal chances of a wetter or drier three months.

Bushfire risks in southeastern Australia have reduced at the start of summer due to rain, but even a short hot and dry spell will see this risk increase quickly again.

We can expect mostly low streamflows across Australia for December 2018 to January 2019.

Low flows observed at 75% of locations in October across Australia. The flows are likely to stay low at by far the majority of measure areas for summer.

December rainfall map

January rainfall map

Chance of exceeding median rainfall (%)

Rain outlook December 2018 - February 2019

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Rainfall (mm)

8 | BWA December 2018