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Snow Modeling R&D: Hydrology Lab Perspectives. Mike Smith NOAA/OHD/HL Cold Regions Hydrology Workshop November 15-19, 2004. Snow Modeling R&D: OHD/HL Perspectives. Ideas derived from:
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Snow Modeling R&D:Hydrology Lab Perspectives Mike Smith NOAA/OHD/HL Cold Regions Hydrology Workshop November 15-19, 2004
Snow Modeling R&D:OHD/HL Perspectives • Ideas derived from: • ‘Reflections on Future Directions in Snow Modeling for the Hydrology Program of the National Weather Service’ (Eric Anderson, 2003) • Victor Koren’s research: energy budget snow modeling, SnowMIP, NCEP model suite.
Snow Modeling R&D:OHD/HL Perspectives • Snow-17: General • Provide RFCs with better understanding of physics and limitations of the model. • More complete documentation of Snow-17 • Further training
Snow Modeling R&D:OHD/HL Perspectives • Snow-17 Lumped Calibration • Better tools: Updated ICP • ICP re-programming funded in FY05 • Basis for enhancements: Areal Depletion Curve analysis • Consistency: calibration to operations • Simulations very sensitive to temperature biases • Need: consistent Mean Areal Temp. algorithm • Short term: Initial: revised diurnal coefficients in OFS MAT • Long term: ‘unified’ MAT • Calibration - Obs. Real Time - Forecast • Based on E. Anderson’s 2004 DOH analysis • Based on instantaneous data
Snow Modeling R&D:OHD/HL Perspectives • SNOW-17 in distributed mode • Why? • Utility of Snow-17 not fully explored • Straightforward enough to run at RFC • Needs • Parameters • Gridded input data • Recommendations: lumped vs distributed mode • Forecast issues: deterministic, ensemble
Snow Modeling R&D:OHD/HL Perspectives • SNOW-17 in distributed mode: Progress • Snow-17 now in HL-RMS distributed model • Testing in MARFC Juniata Basin • Gage-only precipitation • Radar precip. estimates • RUC model gridded temperatures • No areal depletion curve
Snow Modeling R&D: OHD/HL Perspectives Basins of the Mid-Atlantic river Forecast Center Snow-17 in Distributed Mode - Test Basins -Total number of pixels =497 (4x4km) - Watershed area = 8687 km2 - Model parameters = a priori - Channel parameters are derived from USGS measurements at Newport.
Simulations for Raystown Branch at Saxton PA. Distributed API and Snow-17
Snow Modeling R&D:OHD/HL Perspectives • Analysis of Meteorolgical Forcings • Why? • Energy budget models can provide improved simulations compared to Snow-17 in certain conditions. • Energy budget models sensitive to data quality. • Helpful to understand quality of existing and new sources of met. forcing: radiation, wind, etc.
Snow Modeling R&D:OHD/HL Perspectives • Example: Analysis of satellite solar radiation • Rachel Pinker, U. Md: recent satellite solar radiation data very noisy in snow-covered areas. • Modifications • New algorithm for considering cloud cover • Increased resolution • Example: Analysis of QPE-SUMS data • Contexts • DMIP 2 • Large area distributed model runs
Snow Modeling R&D:OHD/HL Perspectives • Areas of potential HL-NOHRSC collaboration • HL understands NOHRSC data processing • Use of SNODAS 1km rain+melt for large area HL-RMS runs • NOHRSC contribute data to DMIP 2 if possible/appropriate. • DMIP 2 addresses science questions pertinent to NOHRSC • HL provides analyses of forcings to NOHRSC • Use of SNODAS for objective updates to Snow-17