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INCA Nowcasting system. RTC Training, Israel November 2017. The lecture topics: System background Infrastructure & I/O Products. System Background. System background. INCA – Integrated Nowcasting through Comprehensive Analysis.
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INCANowcasting system RTC Training, Israel November 2017
The lecture topics: • System background • Infrastructure & I/O • Products
System background • INCA – Integrated Nowcasting through Comprehensive Analysis. • Developed by ZAMG: http://www.zamg.ac.at/fix/INCA_system.pdf • IMS joined INCA-CE project in 2011. • Operational mode since 2013
System background System input Automatic Weather Station Observation measurements INCA System output Numerical Weather Prediction Model forecast Nowcast – short range forecast Weather RADAR Meteorological Satellite
System background • The added value of the system: • High resolution and Bias correction. • Nowcasting. • Improvement of the short range forecast (first 6 hours) and in farther forecasting range.
System background A look “Inside” INCA Forecasted field Temperature & Humidity module Forecasted field NWP NWP processing module Input Wind module Stations/RADAR/Satellite Forecasted field n’th module
System background • NWP processing module • Reads the NWP model fields and Interpolates them to INCA levels and grid: • Spatial resolution: 1km/100m (Lambert Conic Conformal projection). • Vertical resolution: 200m to all fields, except for wind 125m. • Forecast time resolution: 10 minutes/Hourly basis. • Processing includes 2D and 3D interpolation. • The fields on INCA grid are being used by the system’s module to create the Nowcast.
System background Bilinear interpolation (wikipedia): considers the closest 2x2 neighborhood of known pixel values surrounding the unknown pixel's computed location. It then takes a weighted average of these 4 pixels to arrive at its final, interpolated value. The weight on each of the 4 pixel values is based on the computed pixel's distance (in 2D space) from each of the known points. http://en.wikipedia.org/wiki/Bilinear_interpolation
System background Trilinear interpolation (wikipedia): is the extension of linear interpolation, which operates in spaces with dimension D = 1, and bilinear interpolation, which operates with dimension D = 2, to dimension D = 3. http://en.wikipedia.org/wiki/Trilinear_interpolation First we interpolate along z (imagine we are pushing the front face of the cube to the back), giving: Then we interpolate these values (along y, as we were pushing the top edge to the bottom), giving: Finally we interpolate these values along x (walking through a line):
System background • The different modules take into account: • physical effect of the topography. • change of temperature gradient at the boundary layer.
System background • The different modules take into account - continue: • the heating/cooling of the surface during the day/night. • the differences between the NWP to the Observations. • Mass conservation during the wind flow. • The effect of AWS one on the other. • The effect of orography on precipitation… etc.
System background The Analysis & Forecast maps are in 1km/100m resolution. The forecast range is defined by the user First 6-12 hours are combination of system and NWP The rest of the forecast range – donation of the NWP downscaled to INCA’s grid and topography
System background Averaged on 88 AWS for the month of june INCA Analysis INCA forecast NWP
Infrastructure & I/O • Linux based system. • Serial computing (in export version). • Bash shell scripts wrapping c and Fortran code. • At IMS graphics output is with Python and GRADS.
Infrastructure & I/O • Numerical Prediction Model Input: • GRIB 1 format • Hourly basis • At IMS: ECMWF/COSMO • 2D & 3D fields: temperature, precipitation, etc. • Convention: ECMWF+000.grb….ECMWF+012.grb
Infrastructure & I/O • Automatic Weather Station Input: • Hourly/10 minutes • At IMS, database mining using ad-hoc pearl script. • Text file including gathered measurements from stations observation. • Meta data file regarding stations: geographic location, altitude, etc.
Infrastructure & I/O • RADAR data input: • Raw data • Post processed: clutter filtering, CAPPI 1km product. • 5 minutes basis.
Infrastructure & I/O • System output: • ASCII files • BIL (Binary Interpolated ) files – simple binary file without header. • Images • Post-procced data: Meteograms, PDF
Infrastructure & I/O INCA wind module example
Infrastructure & I/O The stages of calculating wind at 10m: Reading INCA topography and land use (Surface type). Calculating f10 factor. Reading stations metadata. Getting precipitation data for effect on wind calculation – optional. Defining system levels. Calculating shaved elements. Reading data stations observations. Reading data from Radio-Sonda - optional. Reading the NWP wind fields in INCA levels and grid.
Infrastructure & I/O The stages of calculating wind at 10m - continue: Finding wind differences between the NWP and stations. Finding wind differences between the NWP and Radio-Sonda - optional. Creating NWP/OBS interpolated differences map. Creating Precipitation wind effect interpolated map – optional. Adding relaxation procedure – mass conservation Creating wind at 10m adding “lake” effect. Writing modules output fields as ASCII and BIL files.
Infrastructure & I/O f10 factor calculation – depends on differences between the INCA and the NWP topography
Infrastructure & I/O IDW Interpolation of the NWP and station wind differences Example is taken from the temperature IDW. Same is done for the wind. Constants for wind are n=4 and c=20. (INCA_system.pdf).
Infrastructure & I/O Shave elements method is used for Mass conservation calculation (INCA_system.pdf). (2011_Haiden_et_al.pdf)
Infrastructure & I/O from DWD slide show about z coordinate system and shaved elements
Infrastructure & I/O Mass Conservation (מתוך INCA_system.pdf).
Infrastructure & I/O Adding the “lake” effect
Infrastructure & I/O Forecast is created by using weights between INCA Analysis and NWP
products • INCA system customers: • Israel Meteorological Service: • Forecasting department/operation center - INCA maps, Forecast to Airfields, NWP/OBS auto-check. • Research & Development department - evapotranspiration , radiation calculations. • Climate department • Chemical Hazard spill application • Israel Hydrology Service/Water Authority • INCA precipitation analysis coupled with Hydrological model. • Israel fire fighters/Police/Road Safety Agency • TV channels • The public
products Snow case 19-20/02/2015
products Grus in Snowing “Hola” valley http://www.nrg.co.il/online/1/ART2/678/158.html
products Nowcast for Airfields
products Severe storm case 7/5/2014
products From INCA_system.pdf