Forecast for Hoosier Legally and Physically Available Yield

Summary

Details

1. Forecast Yield for 2022 is 7,860 acre-feet, which is 60.3% of average actual yield (13,025) from 1988-2021

This forecast was made on May 1, 2022
Data sources:

• from WEAP model Favorite called "Hoosier L&P Actual and Forecast Yield"


2. Forecasts made this year by SEI and WEAP (download CSV)



Forecast Date	Forecast
2/12/2022	5,828 AF
3/2/2022	6,479 AF
3/5/2022	7,438 AF
3/7/2022	7,284 AF
3/15/2022	7,710 AF
4/2/2022	7,438 AF
4/15/2022	7,405 AF
5/1/2022	7,860 AF



3. Unconstrained Yields prior to 2022, with current forecast



Data sources:

• Historical Unconstrained Yields for 1988-2021 from: BlueYields.xlsx:'Unconstrained Yield'!A4:B37


4. Snow Water Equivalent (SWE)

Observed Hoosier SWE on May 1, 2022: 14.3 inches, which is 91% of May 1 average SWE (15.7 in) from 1981-2021

Modeled and forecasted SWE ("Snow Depth (MWE)") compared to Hoosier SNOTEL site ("Snow Gauge")


Data sources:

• Historical SWE from SNOTEL website (SNOTEL Site 531: Hoosier Pass, CO)
• Modeled/forecasted SWE
From WEAP model favorite: "Snow Accumulation vs. Gauge Hoosier 3000 to 3500")


5. Streamflow at Shoshone


Data sources:

• from WEAP model favorite: "Shoshone Gauge Comparison"



6. Streamflow near Cameo


Data sources:

• from WEAP model favorite: "Cameo Gauge Comparison"



7. Precipitation for the Water Year (Oct 1 to Sep 30)


Data sources:

• from WEAP model favorite: "Precipitation Upper Blue"



8. Cumulative WY-to-date precipitation (Oct 1 to May 1)

Cumulative precipitation from Current Water Year start (Oct 1) to date of forecast (May 1); also compared to historical years

Data sources:

• from WEAP model favorite: "Precipitation Upper Blue", summed over weeks from Oct 1 to May 1



9. Cumulative precipitation from forecast date to end of WY (May 1 to Sep 30)


Data sources:

• from WEAP model favorite: "Precipitation Upper Blue", summed over weeks from May 1 to Sep 30

Methods

1. Use of GridMET climate products
Climate data from GridMET: https://www.climatologylab.org/gridmet.html

Direct download and processing into WEAP of:
• Historical daily climate (1979 through 2021)
• Year to date daily climate (Jan 1, 2022 through yesterday)
• Seasonal daily forecast: Available first of each month for 7 months ahead


2. How the climate datasets are assembled



3. How the WEAP model is run
• Forecast to be made on Feb 8 (let's say)
• Use the WEAP interface to update climate datasets, both year to date and seasonal forecast
• Run the model for WY 1980 through WY 2023
• Extract results for Hoosier L&P
• Sum the results from Apr 1 through Nov 30, 2022

WEAP Model

References and Links

1. Forecast streamflows by USDA Natural Resources Conservation Service (NRCS)
• Colorado Forecast Streamflow Point Map
• How NRCS forecasts are made
2. Snowpack Map
3. Gridmet Seasonal Forecast Maps
4. Observed SWE from SNOTEL site 531