What can one really say about a day like this.
A strong cold front approaching from the south-west set up a day of catastrophic fire conditions, with strong north westerly winds gusting to 80km across the lower north of SA bringing minus dewpoints and temperatures above 34 degrees. Combined with a large amount of crop still in the ground, there was enormous areas of tinder dry grass in the Mid North.
The fire started near Pinery, and almost immediately fanned by near gale winds took off uncontrollably to the south-east. The fire grew in intensity but at this stage only had a narrow fire front but was already causing significant damage and expanding on its flanks quite quickly. The significance of the fire was beginning to be realised and within an hour, multiple air bombers and 40 fire fighting units were desperately trying to douse the flames before the expected wind change was to hit. I was west of Hamley Bridge, about 12-15km to the east of the fire at this time watching it grow in intensity and spreading gradually east, and rapidly south and south-east. The town of Mallala was under serious threat at this stage and was being evacuated and houses had already been lost. I knew the very serious threat this fire posed as the classic ‘big fire’ setup was going to occur within an hour and there were no emergency vehicles in sight to warn of the grave danger that this area was soon about to face. The big fire setup refers to the classic summer synoptics involved with cold fronts where hot interior air is dragged down ahead of a cold front, strengthened by the temperature gradient (which in this case was quite large, it would go on to produce snow to low levels in Tasmania). This causes fires to rapidly form long, relatively thin lines which when intersected by the wind change, often at 90 degrees turn the thin line into an enormous wall of flames within minutes and this can happen very suddenly. It was in fact this very same process that caused the Ash Wednesday fires to be so destructive and deadly and today was no exception.
I could see the fire spotting out just ahead of the flanks as the winds gradually turned more westerly and with the front not far away, I back tracked 5km to near Hamley Bridge to give myself a buffer for when the change hit. I could see flames amongst the Mallee trees to the west right as the westerly change hit it and the speed at which this fire increased in intensity was terrifying. The fire was entering its most destructive phase as up to 90km gusts slammed into it forming what was to become a 41km firefront moving at high speeds to the east-north-east. Along with the front came forced uplift, and because there was no smoke out ahead to obscure this sudden release of energy, enormous plumes of smoke billowed rapidly outwards and upwards towards me in a volcanic eruption/pyroclastic flow style. The sudden uplift was sufficient to break the cap under the mid level cloud where the smoke had been limited to, and launched it up way up into the upper troposphere with a pyro cu head and a huge wall of black boiling ash, back lit by the flames. Reports from people in the area suggest flame heights in excess of 20m (from a grassfire like holy shit) with it moving at up to 80km/h. The fire gained momentum so incredibly fast it was in essence likely a firestorm for a short period through the areas of Pinkerton Plains into Hamley Bridge, and southwards towards Wasleys before the fire fragmented into smaller lines due to the gale winds and some towns acting as blocks. Humidity increased and temperature dropped rapidly behind the change and conditions in terms of wind, temps and humidity all gradually moderated in the hours afterward, weakening the fire on approach to Kapunda, southwards into the Barossa Valley. It was still a significant fire at this stage however with widespread ember attacks burning many homes.