WA Radio Scanner Users' Group

FFDI possibly the Forest Fire Danger Index? The one you usually see in our forecasts is the grassland one (McArthur Meter IV).

See http://www.firebreak.com.au/mcarthur_meter.html

Fastlane wrote:FFDI possibly the Forest Fire Danger Index? The one you usually see in our forecasts is the grassland one (McArthur Meter IV).

See http://www.firebreak.com.au/mcarthur_meter.html

Yeah, we used to get the Mark 5? Forest Index over in Sydney and it was usually referred to just as FDI. I only thought it went to 100 but was possible to get it a bit higher in armageddon conditions (super dry air, extremely low fuel moisture content). Anything over 70 was "erratic and uncontrollable".

I know the top end of the meter (50 or 60 +) was found to be way out in prediction of fire behavior, especially for spotting in heavy fuels and ladder fuels (Karri like forests). Not suprising as McArthur did most of his testing on Black Mountain in Canberra which is quite open and would probably be lucky to get past 20tph fine fuels. Some research was going on over here to come up with a new model but I'm unsure how far it got.

It looks like most of the east coast (SA, NSW, VIC) is going to have a bad day saturday, and then we get our share of wind on Sunday and Monday before the heat on Tuesday Wednesday and Thursday... fingers crossed it ends there.

FFDI - Forest Fire Danger Index
GFDI - Grass Fire Danger Index

There are two McArthur meters, one for forest and one for grass. They do have different scales and values. So when refering to a value, you need to specify what meter you are refering to.

observer wrote:FFDI - Forest Fire Danger Index
GFDI - Grass Fire Danger Index

There are two McArthur meters, one for forest and one for grass. They do have different scales and values. So when refering to a value, you need to specify what meter you are refering to.

Actually, there's 3...

yep, there's also the SFDI - Snow Fire Danger Index
Too be honest fastlane I can only find 2 different types, Forest and Grassland, but I can find a Mk 4 and 5 of the grassland.
http://www.firebreak.com.au/mcarthur_meter.html

There is 3, if I can find my wildfire behavior books I will have a look. But the 2 that we use are the grassland one and the bushland one.

Don't forget that over in sydney we have the DI which stands for Drought Index and has a value from 0-200 and anything above 100 its going to be a hard fire to control.

Tyranus wrote:yep, there's also the SFDI - Snow Fire Danger Index
Too be honest fastlane I can only find 2 different types, Forest and Grassland, but I can find a Mk 4 and 5 of the grassland.
http://www.firebreak.com.au/mcarthur_meter.html

That was my point. The Mk 4 and 5 are different and provide different information and use different 'inputs'.. it's not just a 'new version' to outdate the old one..

The third one would be for something along the lines of coastal heath or possible for spinifex country... I'm going for coastal heath.

You also have CALM's "Red Book"...

Helitak_670 & Fastlane, are you thinking of the "Grass Fire Spread Meter" as the 3rd meter?

Also Helitak_670. Don't get the Drought Index (DI) confused with the FFDI. The DI is one of the factors used to determine the Drought Factor (DF), along with the Rainfall to 9am and the number of days between rainfall. THe DF is then used to determine the FFDI, along with the RH, Temp and wind speed. saying that if the DI is high (100+), usually the FFDI will be very high to extreme.

If anyone is around, Weather conditions in Victoria have just deteriorated with massive increases in fire activity.

If you have access, check out the BOM weather radar for Melbourne Airport

http://mirror.bom.gov.au/products/IDR513.loop.shtml

That is NOT rain but heavy forest going up in smoke. Also check the box for show weather observations and not the wind vectors showing the front has moved into the SW of frame (I don't have image posting ability but if you want I can PM you a screenshot.)

Also check out the Bairnsdale radar which is picking up the top of a plume over near Licola?

dlcat1 wrote: http://mirror.bom.gov.au/products/IDR513.loop.shtml

That is NOT rain but heavy forest going up in smoke.

Faaaaaarrrr out!!!

Listening to CFA stream and they have just issued a Red Flag warning to all crews (unknown which fire) but wind change expected at 1800hrs to the south west at 50 - 75 km/hr reducing to 45 km/hr.

Either way not good.

Enviro wrote:Listening to CFA stream and they have just issued a Red Flag warning to all crews (unknown which fire) but wind change expected at 1800hrs to the south west at 50 - 75 km/hr reducing to 45 km/hr.

Either way not good.

I didn't know CFA had a stream.

1800hrs I'd expect it would be one of the fires to the North or SE of Melbourne. Either the Jindivik/Tornimbruk fire or the one that's cut the hume highway.

That's close to the textbook worse case 90 degree wind change

Melbourne airport radar is/was now unavailable. (wind finding?) but Bairnsdale still has coverage and I hope to get some screenshots of the plume movement as the change arrives.