McGuire Fire Burn Area Flash Flood Potential


The McGuire Fire, located in central Idaho,
burned nearly 43,500 acres during it�s lifespan, which began in late August of 2012. As a result
of this intensely burnt area of terrain, flash flooding could become a major threat, especially
for the town of Dixie. The following is information on the potential impacts from flash flooding
that may occur. The McGuire Fire, located in central Idaho,
burned nearly 43,500 acres during it�s lifespan, which began in late August of 2012. As a result
of this intensely burnt area of terrain, flash flooding could become a major threat, especially
for the town of Dixie. The following is information on the potential impacts from flash flooding
that may occur. The area pictured here in orange is the terrain
that was severely damaged by the McGuire Fire. Rainfall runoff will accumulate in the Crooked
Creek watershed, directly affecting Crooked Creek, which runs through the town of Dixie.
This is the particular area of interest, should flash flooding occur.
Here is an example of what the terrain looks like in and around where the McGuire Fire
blazed. You can see that the heavily scorched terrain has little vegetation left to soak
up future rain. This type of burn scar is what primes locations such at this for the
high potential to see flash flooding. So what type of rainfall is necessary for
burn scar flash flooding? The main type of rain is high intensity rainfall produced by
thunderstorms, either from individual thunderstorms, or a line of thunderstorms training over the
burn area. This could definitely produce a flash flood scenario, which, for the McGuire
Burn Area, will be one half an inch of rain or more in 30 minutes. The other type of rainfall
that could occur over the burn area will be stratiform rainfall. This will be a prolonged
period of steady rainfall, which could last a few days. If this occurs, it will NOT yield
a flash flood scenario. Why? Because we NEED high intensity rainfall. This is the most
important thing to remember. Here is a video showing a flash flood that
occurred over a different burn area, which had the same threshold as the McGuire Fire.
This was the result of having met that threshold. Please press the �arrow� button to begin
the movie. Now let�s take a closer look at the Crooked
Creek watershed, and how flash flooding could potentially impact residents of Dixie, particularly
those living close to Crooked Creek. This is a zoomed in image of downtown Dixie,
which could be directly affected by flash flooding along Crooked Creek, which as you
can see from the arrows, runs very closely to homes, businesses, and frequently traveled
roadways. Should flash flooding occur, damage to structures and closure of roadways are
likely due to high water and debris flows. Rock washouts from upstream could deposit
across portions of Main Street and Airway Drive. If the washouts are large enough, road
closures could occur, causing residents to use alternate travel routes for a time.
If you have any further questions on flash flood potential from the McGuire Fire burn
area, please call us at: 406-329-4840, or go to our website at: www.weather.gov/missoula.

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