Compiled Plans & Documents OPW18-0342 02

                                                             Retirement Living & Aged Care Facility
                                                                    Grasstree Court, Sunrise Beach


4.5         Fire Weather
It remains important to understand the influence of fire weather with regard to how it can affect
bushfire risk levels on a daily, weekly or seasonal basis.

In South East Queensland, hot-air fire wind is typically generated by west, north-west and south-
westerlies and cool-air fire wind is generated by south-westerlies which are prevalent during
Southern Queensland’s fire season which extends from August to March, annually. In some situations
however, south-easterlies can also drive bushfire behaviour on occasion.

Notwithstanding the above, it is noted bushfires do not always conform to widely-accepted
characteristics. Other fire weather conditions must also be contemplated such as preceding
weather conditions (such as low rainfall or drought), air temperature and relative humidity. If the
area has been subject to drought or low rainfall for a period of time, vegetation health tends to
deteriorate with increased leaf drop, curing and drying. This contributes to increased ground fuel
loads and general ignition susceptibility. Prolonged dry periods also reduce soil moisture content.

Air temperatures of above 30 degrees Celsius are typically conducive to increased fire weather, as
are extended periods of higher than average air temperatures. In conjunction, low relative humidity
(i.e. low air moisture content) is also a contributing factor to increased fire weather.

In concert, all of the above factors can impact on the ability for fire to propagate, and alter
behaviour and intensity characteristics and as such, fire weather is a significant component of
bushfire hazard. Whilst an assessment of vegetation types, fuel loads, effective slope and other
factors can be readily undertaken, fire weather can fluctuate across days, weeks and seasons and
can have a significant impact on the potential for bushfire threat as well as influence bushfire
behaviour and intensity.

The Forest Fire Danger Index (FFDI) is a commonly used method to readily advise the community of
the likely ability of fire suppression based on fire weather, which is used to inform the Fire Danger
Rating (FDR) System at Figure 4. It is important to maintain awareness as to the level of local fire
danger during the fire season.




                         Figure 5 - Fire danger ratings (Source: RFSQ, 2013)




Status: Final                                                                               March 2019
Project No.: 18-030                                                                            Page 18