Fort McMurry Fire

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  • On this true colour satellite image from 1830UTC on Friday 6th May, 2016, the smoke from the fires (outlined in red) can be seen blowing south-eastwards. The city of Fort McMurry is seen just left of centre in the top half of the image. Image courtesy of NASA.

    The forecast pressure pattern for the coming four days, showing the low pressure system bringing the frontal system, moving eastwards and high pressure building back in across western Canada (Fort McMurry is highlighted with the small red dot).

    The forecast rainfall over central and western Canada over the coming four days (Fort McMurry is highlighted with the small red dot).

    The forecast temperature anomaly (difference between the forecast temperatures and those that are normally expected at this time of year) for the coming four days (Fort McMurry is highlighted with the small red dot).

  • Fort McMurry Fire
    07.05.2016 16:15

    The terrible fire in and around Fort McMurry in Canada have been making headlines in recent days as more than 80,000 people were evacuated from the city in Alberta to escape the path of the wild fire that have led to total devastation in the region. Fires like these are often making headlines around the world as hot and dry conditions make perfect burning conditions for small fires to rapidly grow and spread. Parts of the world that are particularly susceptible are Australia, North America and Asia, although often it is in the wide expanses of minimally inhabited areas that are affected, and it is unusual for a whole city to have to be evacuated, as was the case with Fort McMurry.

    The weather can sometimes lead to these fires starting, with lightning strikes causing sparks and fires to start. In the case of Fort McMurry, lightning was not occurring when the fire started, with the region currently experiencing a great deal of dry and settled weather under high pressure. It is likely that the cause was human. The weather is playing a factor in the growth and spread of the fire though. The Canadian Plains have been experiencing above average temperatures and below average rainfall recently, which has turned a lot of the region into prime tinder for any sparks and fires to start easily and spread quickly. The fires themselves can then help conditions become even more conducive for burning. The heat from the fire is warming the air above them to a greater extent than the surrounding air mass, which then rises, leading to the development of a heat low, similar to what develops over Iberia in the summer months. This difference from the surrounding relatively high pressure, leads to a steepening pressure gradient and strengthening winds, fanning the flames.

    Whilst some control is beginning to come to the situation in Alberta, it will likely need a total change of weather conditions to help get the fire extinguished, with winds needing to drop and rainfall to put out the flames and damp down the smoldering embers, as well as a drop in temperatures. It looks like there will be some rain moving across the region through tomorrow (Sunday 8th) as a frontal system moves eastwards, but this rain could skip to the north of the worst of the fire, which is now to the south of the city. The rest of the week looks like it will be predominantly dry, as pressure builds again and a ridge extends across the region. What the frontal system moving through will do though is to move the anomalously high temperatures away to the east, with temperatures more around the seasonal norm for the rest of the week. Hopefully this will help firefighters on the ground, and all their air support, gain full control of the situation in the near future.

    By: Rachel Vince