MDSS Lab Prototype: MDSS Lab Prototype: Road Weather Forecast System EnhancementsRoad Weather Forecast System Enhancements
Bill Myers
National Center For Atmospheric Research(NCAR)
MDSS Stakeholder MeetingBoulder, CO20 October 2005Photo by Dave Parsons
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Overview
• RWFS Enhancements through Release 4
• Frost Deposition Module• Ongoing Upgrades
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RWFS Enhancements in Release 4.0
• Precip variables’ weights hard-wired– Quality observations lacking– Spatial and inter-variable consistency
• Added snow-water ratio algorithm– Better snowfall estimate
• Refined insolation data sources (model blend)– Model data compared to Vaisala sensor
• MOS forecast interpolation– Improved forecasts where interpolation makes sense
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Frost Deposition Module
• Based on ISU Frost Deposition Model (Tina Greenfield)
• Tries to capture uncertainty in forecast– Frost deposition is very sensitive– Monte Carlo approach varies air temperature, dew point,
and wind speed
• Fuzzy logic interest map applied to each permutation’s output– More credence given to larger frost accumulations– Likelihood of forecast permutation related to weight
• Output– Frost potential (not probability of frost)– Can be thresholded to provided Low, Medium, High alerts
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Frost Module Operations
Weather Forecasts
Road Temp Forecasts
Bridge Temp Forecasts
Bridge Frost Forecasts
Road Condition Forecasts
• Road Temp
• Bridge Temp
• Bridge Frost Potential
MDSS 4.0 generates Bridge Frost forecasts though Road Frost could be calculated
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Ongoing Weather Forecast Improvements
• Improved forecasts of extreme events– Model Error Correction (MEC) captures rare events better
than current scheme (Dynamic MOS)
• Incorporation of radar data– Precipitation extrapolation provides better forecast in first
few hours (than model/RWIS combination)– Need to trend toward model forecast seamlessly– Provides improved spatial pseudo-observations
• Higher resolution NCEP data– GRIB-2 encoded model data is available– Fully uncompressed data sets are unwieldy– Need tools to extract only relevant information