Soil Saturation - Warning Decision Training Division (WDTD)

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Soil Saturation

Short Description

A comparison of the current model output of the water content in the top-layer soils at model initialization time to the maximum storage capacity of those top-layer soils.

Subproducts

CREST and SAC-SMA. The FLASH EF5 framework runs multiple hydrological models using a common input. For MRMS Version 12, there is a soil saturation product for the 2 models listed above.

Primary Users

NWS: WFO, RFC

Input Sources

MRMS Radar-Only QPE

Resolution

Spatial: ~1 km x 1 km

Temporal: 10 minutes

Product Creation

The FLASH EF5 model framework uses MRMS Radar-Only QPE as input into the 2 hydrological models (CREST and SAC-SMA) which then use a subset of these hydrological principles (infiltration, storage, interflow, evapotranspiration, and runoff) to route the precipitation through the basins. The amount of modeled water content in the top-layer soils at model initialization time for each grid point is compared to the maximum storage capacity of those top-layer soils in each grid point. The result is a percentage value of maximum storage capacity.

Technical Details

Latest Update: MRMS Version 12

NOTE: In version 12, all FLASH products now use the instantaneous rainfall rates from the Dual-pol radar synthetic QPE product.

Accessible on:

Operational AWIPS
1. V11.5 -- MRMS menu
2. V12 -- via LDM, if set-up
MRMS Development site

References

Gourley, J., Z. Flamig, H. Vergara, P. Kirstetter, R. Clark III, E. Argyle, A. Arthur, S. Martinaitis, G. Terti, J. Erlingis, Y. Hong, and K. Howard, 2016: The Flooded Locations And Simulated Hydrographs (FLASH) project: improving the tools for flash flood monitoring and prediction across the United States. Bull. Amer. Meteor. Soc. doi:10.1175/BAMS-D-15-00247.1, in press.

Jiahu Wang , Yang Hong , Li Li , Jonathan J. Gourley , Sadiq I. Khan , Koray K. Yilmaz , Robert F. Adler , Frederick S. Policelli , Shahid Habib , Daniel Irwn , Ashutosh S. Limaye , Tesfaye Korme & Lawrence Okello (2011) The coupled routing and excess storage (CREST) distributed hydrological model, Hydrological Sciences Journal, 56:1, 84-98, DOI: 10.1080/02626667.2010.543087

Strengths

By modeling the water cycle using these more robust state-of-the-science hydrological models, flash flood prediction becomes more objective and scientifically sound.

Limitations

All limitations associated with MRMS Radar-Only QPE apply

Significant amounts of snowmelt are not accounted for in this version of FLASH

FLASH model does not account for river diversions such as dams

Rainfall forcing is stopped at the model initialization time

No post-processing of data, so model values may not be representative of in-situ, or remotely sensed observations.

Quality Control

This product is subject to the MRMS 3D Reflectivity Cube quality control (QC) process.

Applications

Diagnose antecedent conditions conducive to flash flooding (e.g. previous flooding events)

Compare with recently updated FFG grids

Example Images

Figure 1. Example of Soil Saturation where there is a broad area of values exceeding 50% which indicates that there has been recent rainfall in the area which might lead to quicker flash flooding if another precipitation event moved over this area.