Event (6) Intense spotting on fire flank

Air Observer

This photo looking from Uriarra Crossing to Pig Hill,shows a stable lateral edge of a smoke plume. A large number of spot fires can be seen under or just outside of the shadow of the plume. One of these spotfires was observed to become established and reach maximum rate-of-spread within three minutes of ignition, despite five helicopters arriving within that time. Note that documented channelling events were underway at the back of this flank (at Pig Hill) and in the lower-left corner of the image (at Uriarra Crossing).

Field Observer

This photo is a still from a WIN TV news video 149.03° -35.34° looking NW at about 16:00 AEDST on 18th January, 2003.

This photo, taken in Eucumbene Drive in Duffy, shows the typical situation downwind of a channelling event. The landscape is ignited by spotfires, which rapidly amalgamate. There is no headfire. The smaller headfires are being drawn toward established ones. The latter often have tall flames (over 90m has been confirmed), but little or no lean on the flames.
Also associated are ember storms, which require strong winds. It is likely that a sequence of events occurs, culminating in the spot fires.
Observer safety becomes the initial concern if this is seen, followed by reporting the observation.

Implications

Phenomenon	Urgency	Indicated Red Flag Warning
Dynamic channelling	2	6) Channelling event
Deep flaming zone	?	2) Conditions conducive to plume-driven fire
Violent pyro-convection	?	1) Plume-driven fire
Wind Change at Fire	?	5) Wind change
Convergence Zone	?	????

Browsing the Event List

Previous event page

Event List

Next event page

This material arises from work carried out by the HighFire Risk Project.

Material prepared by R. McRae September 2009.