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Woodson Lees Ferry WY flow forecast: Difference between revisions

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This streamflow forecast uses a machine learning (random forest) model trained on [https://www.usbr.gov/lc/region/g4000/NaturalFlow/LFnatFlow1906-2023.2023.8.17.xlsx Reclamation annual natural flow for the Colorado River at Lees Ferry, AZ] for water years 1921-2023 as the predictand and predictors including Pacific Decadal Oscillation (PDO; https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat) index, Atlantic Multidecadal Oscillation (AMO; https://www1.ncdc.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.amo.dat) index, as well as Community Earth System Model - Large Ensemble (CESM-LE; https://www.cesm.ucar.edu/community-projects/lens/data-sets) precipitation and minimum temperature forecasts. The PDO and AMO predictors are July-August-September averages preceding the start of each water year and the CESM-LE precip. and temp. predictors are October through September averages coinciding with the water year being forecast. E.g., for the 2024 water year forecast (October 2023 - September 2024 total natural flow), PDO and AMO predictors are July 2023 through September 2023 monthly averages and CESM-LE precip. and temp. predictors are October 2023 through September 2024 monthly averages. The random forest forecast is a 600-member ensemble.
This experimental streamflow forecast uses a machine learning (random forest) model trained on [https://www.usbr.gov/lc/region/g4000/NaturalFlow/LFnatFlow1906-2023.2023.8.17.xlsx Reclamation annual natural flow for the Colorado River at Lees Ferry, AZ] for water years 1921-2023 as the predictand. The predictors include:
*[https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat Pacific Decadal Oscillation] (PDO) index, July-August-September average preceding the water year being forecast
*[https://www1.ncdc.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.amo.dat Atlantic Multidecadal Oscillation (AMO) index, July-August-September average preceding the water year being forecast
*[https://www.cesm.ucar.edu/community-projects/lens/data-sets) Community Earth System Model - Large Ensemble (CESM-LE) forecasts of precipitation and minimum temperature, October through September average coinciding with the water year being forecast  
For example, for the 2024 water year forecast (October 2023 - September 2024 total natural flow), PDO and AMO predictors are July 2023 through September 2023 monthly averages, and the CESM-LE precipitation and temperature predictors are October 2023 through September 2024 monthly averages. The random forest forecast is a 600-member ensemble.


The second plot below shows the 'variable importance' for each predictor over the 1921-2023 training period; each variable does add value (this is how the variables were selected), and AMO and PDO have the highest importance.
The second plot below shows the 'variable importance' for each predictor over the 1921-2023 training period; each variable does add value (this is how the variables were selected), and AMO and PDO have the highest importance.

Revision as of 11:25, 27 November 2023

This experimental streamflow forecast uses a machine learning (random forest) model trained on Reclamation annual natural flow for the Colorado River at Lees Ferry, AZ for water years 1921-2023 as the predictand. The predictors include:

For example, for the 2024 water year forecast (October 2023 - September 2024 total natural flow), PDO and AMO predictors are July 2023 through September 2023 monthly averages, and the CESM-LE precipitation and temperature predictors are October 2023 through September 2024 monthly averages. The random forest forecast is a 600-member ensemble.

The second plot below shows the 'variable importance' for each predictor over the 1921-2023 training period; each variable does add value (this is how the variables were selected), and AMO and PDO have the highest importance.