Since the Park Fire began Wednesday afternoon, residents from Butte and Tehama Counties have seen plumes, or column-like clouds, form above the skies of the fire.
Firefighters are calling the Park Fire a “plume dominated fire,” and Cal Fire – Butte County Public Information Scott McClein took time Sunday to explain how the plumes affect the fire’s activity.
“When you talk about a plume aspect, as you look outside you can see that column of smoke rise, and then it gets to that bright white at the very top because it has developed itself,” McClein said. “It’s now developed its own weather and any wind, so when a plume dominates it increases in size.”
A plume will develop into the sky and will eventually collapse, McClein said. What is concerning about that is when the plume does in fact collapse, it brings wind with it that will blow in 360 degrees.
“It’s not a breeze, it’s a wind,” McClein said. “Unfortunately that pushes the fire in multiple different directions, and on our side that’s what we look at. Again it does promote that smoke to go in various different directions as well, but in the fire world it’s extremely dangerous because of the multiple directions it goes in.”
California has had a wet past two years, followed with high temperatures this summer. The excessive moisture has brought more vegetation, which then has dried out due to the high temperatures.
“You combine that together, and everything is very susceptible to fire,” McClein said.
The plumes are formed when heat rises during the day on the fire, and are later cooled down at night by colder air forcing the air to be heavier.
“Now that fire’s going to turn around and come back down the hill and a plume may form,” McClein said. “That’s a simple example of what we have to pay attention to and be aware of.”
The other type of fire is considered a terrain driven fire. However, McClein noted that many fires are a mix of the two depending on the typography. Butte County and Northern California are prone to both types, McClein said. Terrain driven fires begin on the ground level and develop a weather pattern as well, but are often in narrow areas pushed by wind through heavy brush-filled areas.
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When Saturday hit, many of the plumes of smoke could not be seen any longer from most of Chico, and McClein explained that was due to an inversion layer. The temperature dropped 10-15 degrees, winds have been slight, and the smoke shields the sun.
“That smoke is at a certain area, and once that inversion layer breaks that’s holding the smoke, then it’s going to break this afternoon more than likely, so you’re going to get some sunshine,” McClein said.
McClein said that when the sun comes through the inversion layer, temperatures will rise, and fire activity is a strong potential. This makes watching the weather extremely important for all fire personnel.
McClein stressed the importance of the, “ready, set, go” model.
“Always be up and in this area,” McClein said. “Set. Make sure you have everything ready to go. Car is fueled and pointed out. And go when there’s an order to go. It’s hurting firefighters if they can’t get in.”