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Final Program


Oral

2025 Symposium on Hydro-climate and Climate Change (Watershed)

A Seasonal Forecasting System for the Sacramento River Basin in California

Monday, May 19, 2025
3:00 PM - 3:15 PM Alaska Daylight Time (AKDT)
Room: Room 1
Abstract Submission: In order to forecast monthly river inflows to outlet locations of various sub-basins of the Sacramento River Basin in California during January – July period of the year, a numerical atmospheric/hydrologic modeling system was coupled with a statistical updating system to create a seasonal flow forecasting system. This system first dynamically downscales the global forecasts of NOAA’s Climate Forecast System Version 2 (CFSV2) to the region of the Sacramento River Basin at 9 km grid resolution and hourly intervals by means of the Weather Research Forecast (WRF) regional atmospheric model. Then the refined climate forecast outputs from WRF are input into the Watershed Hydro-climate Model (WEHY-HCM) which is made up of the Watershed Environmental Hydrology (WEHY) model that is coupled to the WRF model. With these inputs, first the land surface conditions, especially the snow conditions over Northern California are forecast. Then these forecasts are integrated to other hydrologic components of the WEHY model in order to develop the monthly flow forecasts at various sub-basin outlets of the Sacramento River Basin during the January – July period within each year. These atmospheric/hydrologic numerical model-based monthly flow forecasts are then updated by monthly flow observations at the sub-basin gage sites by an exponential smoothing filter in order to issue the final monthly forecasts. This seasonal forecasting system will be described by means of an example application to one of the sub-basins of the Sacramento River Basin.

Learning Objectives/Expected Outcome (Optional) :