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www.meteogroup.com. WRF for winter roads. Hugo Hartmann , Jelle Wisse, Daniël van Dijke. Presentation 7B.5 – 14th Annual WRF User’s Workshop, 24-28 June 2013. Winter roads…. Winter is beautiful. but that is not the topic of this presentation….
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www.meteogroup.com WRF for winter roads Hugo Hartmann, Jelle Wisse, Daniël van Dijke Presentation 7B.5 – 14th Annual WRF User’s Workshop, 24-28 June 2013
Winter roads… Winter is beautiful... but that is not the topic of this presentation… Winter is also very dangerous for public safety!
RoadCast • A weather forecasting service of MeteoGroup
Outline • MeteoGroup‘sRoadCast • WRF casedefinition • Results • Conclusions & Outlook
RoadCast RoadCast core “Land-surface model” Local measurements Route based forecast Database with for all routes: sky and solar view factor Weather forecast…
RoadCast sensitivity to temperature variations Forecastof roadsurfacetemperature Observedroadsurfacetemperature Otterlo Otterlo 17 Feb 2011 (clear-skynight) Ede Ede Arnhem Arnhem • Observedtemperaturevariations are more extreme (land-use, topography) • Solution: usemeasured air temperatureprofile as input to the model (thermal map) WRF?? EXPENSIVE!
RoadCast RoadCast core “Land-surface model” Local measurements Route based forecast Database with for all routes: sky and solar view factor Weather forecast… Thermal map, TT measurement / simulation
WRF case definition • Project aim: Investigatewhether WRF is able to simulaterealisticlocal air temperaturevariationsduringclear and calmnights • Domain of interest: Wales, complex terrain ridge 22 km ridge valley 16 km 0 km valley 10 km 35 km 28 km Google Earth
WRF case definition Synopticsituations (clear-sky) CASE ‘EAST’ – EASTERLY WIND CASE ‘NORTH’ – NORTHERLY WIND March 26-27, 2012 March 28-29, 2012
WRF case definition WRF 3.3.1 (7.5 km – 1.5 km – 0.5 km) • ECMWF 00z input (0.125° 15 km) • One-waynested • Simulation time: 2 days (1 dayspin-up) • 39 eta levels (first level 10 m) • 148 x 148 gridpoints (0.5 km) 7.5 km 0.5 km 1.5 km Google Earth WRF 7.5 km WRF 1.5 km WRF 0.5 km
Results (0.5 km) – 15 UTC EAST NORTH N 0 20°C 0 20°C 0 10 m/s 0 10 m/s
Results (0.5 km) – 5 UTC EAST NORTH N 0 20°C 0 20°C Page 13 0 10 m/s 0 10 m/s
Results – 5 UTC EAST NORTH Page 14
Results – Ridge EAST NORTH
Results – Valley EAST NORTH
Conclusions & Outlook • More cases needed • Thermal map strongly depends on wind speed/direction, stability atmosphere) • 1.5 km / 0.5 km comparable results, but steep peaks/valleys still not resolved satisfactory • Explore potential of improved wind parameterization scheme (Jimenez and Dudhia, 2011) • Explore other PBL schemes • Nearest neighbour procedure not the best option for generating the thermal map • develop alternative methodology(ies) for representative gridpoints
www.meteogroup.com Thankyou