Wind is the most common weather-related cause of outages for City Light’s transmission and distribution system. Current design, maintenance and emergency response of the system are based on historical windstorm seasonality, direction, frequency, and intensity (i.e. wind speed). Changes in regional climate are projected to alter windstorms and lightning risk, potentially shifting the frequency and intensity of outages in City Light’s service area. Information on projected changes in wind under future climate scenarios can help inform both short and long-term adaptation strategies to reduce vulnerability to wind and lightning.

Results are based on three regional climate simulations using the WRF (Weather Research and Forecasting) regional climate model, each driven by a different global climate model. Wind is included in the model outputs; lightning risk is estimated using the Thunderstorm Potential index. Model results are analyzed for both a historic (1970-2000) and a projected future time period (2040-2070).

Seattle City Light Climate Change Analysis: This report looks at climate change effects on regional climate, streamflow, and stream temperature to support Seattle City Light’s assessment of impacts of projected climate change on operations at the Skagit and Boundary hydroelectric projects and on future electricity load in its service territory.

Seattle City Light 2015 Climate Change Vulnerability Assessment and Adaptation Plan: The plan assesses the potential impacts of climate change to the utility and identifies actions that can be taken to reduce vulnerability and increase resilience.

Seattle City Light Historical Climate Trends data visualization and report: This work was designed to provide a centralized assessment of historical trends across a range of locations and metrics that are of interest to Seattle City Light.