Wildfire risk remains high in southern Alberta

                                    

PINCHER CREEK EMERGENCY SERVICES

F I R E  -  A M B U L A N C E  -  R E S C U E

EMERGENCY “911”     OFFICE 627-5333  

Pincher Creek Fire Chief Dave Cox

Fires in structures occur at any time of the year and we have smoke alarms and a large fire prevention program internationally to reduce fire occurrence and minimize the damage a fire can cause.

Wildfires in Alberta receive at lot of attention during the spring, summer, and fall and again a large prevention program is dedicated to minimizing their impact.

What a lot of people do not appreciate is the risk of wildfire that occurs during winter.

Wildfires start from any number of sources. In summer there is a mix natural starts (lightning) and human caused starts. When the storm season ends the risk of starts still exists, predominately from humans.

Fires need three things to burn [fuel, air (oxygen), and heat]. If any one of these things is taken away the fire cannot burn.

These three things are readily available. They just need to be put together to get a fire.

Wildfires can vary from “smoldering” which grow in size very slowly and are usually easy to put out to “running” (or in the case of forest fuels, “crowning”) which grow rapidly in size and can be very difficult to put out.
This variance or fire behavior is controlled by three things; weather, fuel, and topography.
Briefly,

 Weather is the greatest variable with temperature, relative humidity, precipitation, and wind all either contributing to or hindering the growth of a fire.

Fuel in the case of wildfire is anything organic. The most important variable in fuel is whether is it living or dead. Living fuel has a lot of natural moisture and a process to maintain that moisture even when it is very dry. Dead fuel responds to the weather conditions constantly either taking on or losing moisture according to the relative humidity or precipitation.

The moisture level in a fuel determines how a fuel or even if a fuel will burn. This plus the amount of fuel and how it is arranged will determine how intense a fire is.

Topography also has an effect on fire behavior as aspect, slopes, and other features such as gullies, rock or dirt exposures, creeks, and rivers all contribute to a fire’s behavior. These features also impact the type of fuel that grows there as well. 

In any geographical area if the cards all lined up and there is a start there will be a fire regardless of the time of year.

In Southern Alberta the cards can line up any month of the year.

We currently have all the cards lined up.

We had a good growing season this last summer so there is lots of grass, stubble left over in fields, pastures, road ditches, yards, etc.

This fuel due to a dry fall and the normal cycles has all died (or cured in fire terms) so it is readily available to burn if the weather conditions are right.

The weather conditions this winter have certainly been right. We have little or no snow. We are getting lots of Chinook conditions which translates into warm, dry (low relative humidity), and windy.

With these conditions, all that is needed is a start.

In November major fires burnt around Lethbridge and south of Lethbridge in the Magrath area. This last week (in January) there were two major fires in the Willow Creek MD and one east of Medicine Hat extending into Saskatchewan.

There does not appear to be an end in sight with little snow and more Chinook conditions forecast. The abundance of dead or cured fuel we have will rapidly dry out and more major fire events may occur.

We are left with trying to minimize the starts. Mechanical or structural failure (powerlines blown down, vehicles blown over, etc.) is only part of the problem. Any normal activity involving anything that could start a fire (cleaning a stove, outdoor cooking, welding, thawing out a frozen pipe, etc.) needs to done with as much or more caution than we would have in the summer (our traditional fire season). 

If a fire starts it is critical to call the fire department as soon as possible. The quicker that action can be taken the better the chances are of keeping the fire small.