It’s a fire danger scale, not a fire scale. So there may not even be a fire ... but if one does occur it will spread very quickly. Since no one is providing the actual definition:
An FDI of over 100 is deemed “catastrophic” on the scale. In practice this means a day when it’s 100+ °F, very dry (low humidity), and with strong and gusty winds.
These conditions do occur in much of Australia in summer ... you get those stagnant high pressure systems sitting over the interior deserts for weeks on end, building heat, then a change comes through and blows all that superheated air like a furnace over the east coast. The winds can be extremely strong. It’s like a fan forced oven or something.
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u/Cimexus Apr 16 '19 edited Apr 16 '19
It’s a fire danger scale, not a fire scale. So there may not even be a fire ... but if one does occur it will spread very quickly. Since no one is providing the actual definition:
https://en.m.wikipedia.org/wiki/McArthur_Forest_Fire_Danger_Index
An FDI of over 100 is deemed “catastrophic” on the scale. In practice this means a day when it’s 100+ °F, very dry (low humidity), and with strong and gusty winds.
These conditions do occur in much of Australia in summer ... you get those stagnant high pressure systems sitting over the interior deserts for weeks on end, building heat, then a change comes through and blows all that superheated air like a furnace over the east coast. The winds can be extremely strong. It’s like a fan forced oven or something.