Victor Koren’s modified Sacramento model has been integrated into the Hydrology Laboratory's Research Modeling System (HL-RMS) distributed model. His new Sacramento model combines the principles of heat transfer and physical soil properties to compute physically-based estimates of soil moisture and soil temperature (see Appendix).

In another development, HL-RMS has been modified to run over the entire continental US (CONUS). Victor, Fekadu Moreda, and Zhengtao Cui recently ran the new versions of the SAC model and HL-RMS over CONUS using seven days of hourly NEXRAD (NEXt generation RADar) Stage IV data as shown in Figure 1.  Figures 2, 3, and 4 show actual computed soil moisture content in three different layers at the end of the seven day run of HL-RMS.  Figure 5 shows computed surface runoff.  In all these figures, the modeling resolution is 4km by 4km.

We see such large scale, high resolution tests as an exciting opportunity to develop new tools and prototype products for future RFC forecast operations:

1. Prototype versions of new water resources products can be tested. These include soil moisture and soil temperature for agricultural users. Such products are foundational to the NOAA Water Resources program as shown in Figure 6.

2. Gridded values of physically-based soil moisture can potentially be used to evaluate Flash Flood Guidance (FFG).

3. CONUS-scale runs will allow us to more effectively identify where our modeling efforts work and where they need improvement. This results in an accelerated research-to-operations pathway.

4. Research collaborators such as the University of Arizona can more effectively test their modeling improvements and calibration strategies. The University of Arizona is currently working with a version of HL-RMS running on their system.

5. New distributed model calibration strategies can be tested.

6. CONUS runs of HL-RMS can expedite the evaluation of new precipitation products such as National Severe Storms Laboratory’s NMQ (National Mosaic and multi-sensor Quantitative precipitation estimation) and Q2 (next generation Quantitative Precipitation Estimation).

7. Such testing supports NOAA mission goals listed in the NOAA 2005-2010 Strategic Plan:

1. Performance objectives for Weather and Water Mission Goal:

Increase development, application, and transition of advanced science and technology to operations and services.

2. Cross Cutting Priorities:

Ensuring sound, state-of-art research.

8. CONUS runs of HL-RMS can contribute to the development of the National Integrated Drought Information System (NIDIS).

Fig.2  4km Computed Soil Moisture in 0-25cm layer at hour 0, June 17, 2004.  (Enlarge)

Fig.3  4km Computed Soil Moisture in 0-5 cm Layer at hour 0 on June 17, 2004.  (Enlarge)

Fig.4  4km Computed Soil Moisture in 25-100cm Layer at hour 0 on June 17, 2004.  (Enlarge)

Fig.5  4km Computed Surface Runoff at hour 0 on June 17, 2004. Units are in mm/hour.  (Enlarge)