September 11, 2025, by Research Science

Dear Sitka Community,

The Science Center extends its sympathies to the people whose homes were impacted by the slope failure at Cascade Creek Road last night. We are relieved that there was no loss of life. As we enter the autumn and our storms become more frequent and intense, we want to take this opportunity to remind the community of the tools they have at their disposal for assessing weather and hazard conditions to make decisions around their safety.

The best resource for learning about incoming rain events and their potential impacts is the National Weather Service’s Juneau Office. You can access the office’s forecast information at wwww.weather.gov/ajk, where you can see their 5-day-outlook, and can click on Baranof Island on their interactive map for a detailed day-by-day forecast for Sitka and to access any relevant Special Weather Statements. You can also access their Facebook and X pages.

After checking the NWS forecasts, another tool you can refer to in order to assess potential impacts of heavy rainfall events is the Sitkalandslide.org dashboard. The Sitkalandslide.org dashboard uses rainfall data from the airport, forecasts from the National Weather Service, and historical landslide data from landslides in the past 20 years in the Sitka area to generate landslide risk level predictions. Posted risk levels are combined with recommended actions to guide community members toward emergency preparedness and informed decision-making during periods of elevated hazard, with the goal of protecting human life.

Hillslopes with alterations such as road cuts or other infrastructure can fail at lower rainfall amounts than natural hillslopes. We recommend additional caution on or beneath these slopes, even when forecasted landslide risk is “low” or “moderate.” Note that a “low” risk level on the dashboard does not mean that the risk level is zero.

 

There have been recent outages all over Southeast Alaska for the communications services that send precipitation data to the Weather Service and to our dashboard in real time. Unfortunately, the airport’s rainfall data is not currently connecting to our dashboard. If the dashboard had received the rainfall data in real-time from the airport, it would have triggered a “moderate” risk level forecast, beginning around 6pm (graph shown below). We are monitoring this situation and will put updates out on our social media when this issue has been resolved. In the meantime, the dashboard is still providing future risk level predictions based on NWS forecasts. You can learn more about the dashboard, landslides, and how you can prepare for them at https://sitkascience.org/research-projects/landslide-warning-system/.

We look forward to communicating additional tools and guidance for how to assess risk and make decisions around your safety. For any questions or to get in touch with our geohazards team, please reach out to landslides@sitkascience.org.

Thank you and stay safe,

The Sitka Sound Science Center team