As the Valley Fire in Northern California continues to burn, the forecasted rain can help and hurt.
The Valley Fire north of San Francisco, CA has burned 70,000 acres and is 30% contained. Active fire and visible flames still cover a lot of the area, and the rain expected today will likely help firefighting efforts to cool and douse these parts of the fire. However, for the areas already scorched by this blaze, like Middletown, with burned, unprotected soil, the rain brings further concerns of landslides and flash flooding.
Many variables lead to increases in risk for an area for landslides and flash floods. One such consideration is recently burned areas that have little to no vegetation to hold the soil in place and minimize erosion. Another notable fire in Northern California is the Butte Fire (71,780 acres, 45% contained) near San Andreas which is also in areas of mountainous terrain. This increased slope is another concern after a wildfire when rain approaches.
Images like the one seen above (taken by a RedZone Liaison on the ground near the Valley Fire today) are becoming common as large wildfires continue to burn across the Western US and Alaska this fire season. Many show no signs of being contained until snowfall.