Hydrometeorological Observations

Background

Scientists in RAL’s Hydrometeorological Applications Program (HAP) are actively engaged in numerous observational studies aimed at improving the understanding of critical processes that control various linkages in the water cycle.  In FY2017 and FY2018 staff have engaged in several field observation efforts focused on winter precipitation, snowpack, snowmelt and runoff.  In addition to requiring a comprehensive scientific research strategy, these projects demand significant integration of instrument engineering and field work skills to collect research-quality data in Colorado’s extreme mountain environments.

High-elevation monitoring for snowpack and water supply predictions

Background

Figure 1:  HydroInspector web mapping service display of observation stations (white circles) and observation and model time series (right hand side time series plots) from the Upper Rio Grande observation and modeling project.
Figure 1:  HydroInspector web mapping service display of observation stations (white circles) and observation and model time series (right hand side time series plots) from the Upper Rio Grande observation and modeling project.

In 2017 a network of snowpack, soil moisture, near surface meteorological and stream water level measurement stations was maintained in the Conejos River basin in southern Colorado (see Fig 1 below). White circles indicate location of NCAR measurement stations, blue squares are NRCS SNOTEL stations, green triangles are Colorado Division of Water Resources streamflow stations).   These stations were deployed in 2014 as part of the inter-agency Rio-SNO-FLO project which is performing observational and modeling based research aimed at improving the characterization and prediction of snowpack and seasonal water supplies in the headwaters of the Upper Rio Grande.  This work is being done in collaboration with the Conejos Water Conservancy District, the State of Colorado, the NOAA Severe Storms Laboratory and NASA’s Jet Propulsion Laboratory.  Research conducted during 2017 documented the performance of observed vs. modeled snowpack depth and near-surface temperature, humidity, and incoming solar radiation.  These results are summarized in a report to the State of Colorado (Gochis et al., 2016; Karsten et al. 2017).  The principal outcomes of this work were that research radars possessed significant skill in estimating mountain snowfall as validated by surface precipitation gauges in the southern Colorado region and that when used to drive a physics-based hydrologic model, resulting snowpack and streamflow simulations were significantly improved over simulations using background national analyses of precipitation. Additionally, it was also found that direct insertion of airborne lidar derived estimates of snowpack across the basin into a high-resolution hydrologic model had a direct and positive impact on snowmelt-driven seasonal water supply forecasts.  As a result, the State of Colorado is currently exploring financial alternatives to purchasing and deploying a gap-filling radar in the Upper Rio Grande basin.

Gochis, D.J, K. Howard, J. Busto, J. Deems, N. Coombs, L. Tang, I. Maycumber, K. Bormann, L. Karsten, A. Dugger, N. Langley, J. Mickey, T. Painter, M. Rchardson, and S.M. Skiles, 2016: Upper Rio Grande Basin Snowfall Measurement and Streamflow (RIO-SNO-FLOW) Forecasting Improvement Project. Project report submitted to the Colorado Water Conservation Board. Available online at: http://cwcb.state.co.us/public-information/publications/Pages/StudiesRep....

Karsten, L., D.J. Gochis, A. Dugger, K. Howard, L. Tang, J. Deems, T. Painter, G. Fall, C. Olheiser, 2017: Assessing the impact of operational meteorological forcings and experimental radar snowfall estimates on simulated snowpack conditions in the headwaters of the Upper Rio Grande River basin, In preparation.

2018 Accomplishments

Figure 2: GoogleEarth map plot of the proposed installation sites (yellow balloons) of 4 new SNOTEL lite stations to be deployed in the Upper Taylor River Basin near Crested Butte, Colorado.  Inset photo shows the system hardware.
Figure 2: GoogleEarth map plot of the proposed installation sites (yellow balloons) of 4 new SNOTEL lite stations to be deployed in the Upper Taylor River Basin near Crested Butte, Colorado.  Inset photo shows the system hardware.

In collaboration with the Upper Gunnison River Water Conservancy District (UGRWCD) and the Natural Resources Conservation Service (NRCS) NCAR installed 4 new SNOTEL-Lite stations in the Upper Taylor River basin in southern Colorado. (Use the same figure2)

Real-time measurements from these stations are being fed into the GOES satellite communication system and are being downloaded and integrated into the operational NRCS station data stream.  NCAR is currently in the process of displaying this information for the UGRWCD using the NCAR/RAL HydroInspector tool along with other model-based snowpack and streamflow prediction products.

In collaboration with the Conejos Water Conservancy District, the State of Colorado, the NOAA Severe Storms Laboratory and NASA’s Jet Propulsion Laboratory  5 new SNOLITE stations were installed in the headwaters of the Conejos River basin in Upper Rio Grande basin in southern Colorado. The data from these stations is in the process of being telemetered via GOES satellite back to NCAR for quality control, archival, analysis and model evaluation.

In FY2019 and beyond these stations will be used to validate model-estimated and remotely-sensed observations of snowpack, soil moisture, precipitation, and other near-surface meteorological conditions.