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6/29/2005 Q2 Workshop, Norman, OK 3-D Radar Mosaic and Initial Q2 Development Plans Jian Zhang 1, Ken Howard 2, and Steve Vasiloff 2 1 University of Oklahoma, Norman, OK 2 National Severe Storms Lab, Norman, OK
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Outline NMQ Components Overview Single Radar Process 2-D Radar Mosaic 3-D Radar Mosaic Initial Q2 Development Plans Outlook
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Outline NMQ Components Overview Single Radar Process 2-D Radar Mosaic 3-D Radar Mosaic Initial Q2 Development Plans Outlook
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Radar Satellite Sfc Obs & Sounding Lightning Model QPE Ingest & QC & QC Rain Gauge HydroModel* NMQ Overview Flowchart PrecipProducts HydroProducts Users QPF 2D/3DRadarMosaic MosaicProducts Verification
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Radar Satellite Sfc Obs & Sounding Lightning Model QPE Ingest & QC & QC Rain Gauge HydroModel* NMQ Overview Flowchart PrecipProducts HydroProducts Users QPF 2D/3DRadarMosaic MosaicProducts Verification
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NMQ Philosophy An open R&D system Dynamic enhancements/improvements to scientific components Real-time 24/7 testing and evaluation on CONUS domain to address real-world problems A real-time verification system Cost-effective algorithms for operational benefits Incorporation of new data as they become available A common framework for joint scientific research and development
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Data Ingest Radar WSR-88D, level-II and level-III (140+radars) WSR-88D, level-II and level-III (140+radars) Canadian radar network (~35 radars, efforts undergoing) TDWR (ongoing, limited data availability) CASA/gap-filling radars (future) Dual-pol radar data (future)
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Data Ingest (Cont.) Satellite GOES IR imagery data (Tb) GOES IR imagery data (Tb) For QC and radar-satellite QPE For QC and radar-satellite QPE GOES sounder data (ECA) GOES sounder data (ECA) For QC For QC Other (GOES multi-spectral, exploring) Auto Estimator (efforts undergoing) GMSRA (future) GMSRA (future) GOES Multi-Spectral Rainfall Algorithm SCaMPR (future) SCaMPR (future) Self-Calibrating Multivariate Precipitation Retrieval
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Data Ingest (cont.) Rain Gauge Rain Gauge NCEP/USGS hourly gage data NCEP/USGS hourly gage data OK mesonet OK mesonet Additional gage networks (mesowest, LCRA, prism) Other?
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Data Ingest (cont.) Model (RUC 20km, hourly analysis) Model (RUC 20km, hourly analysis) Upper Air Sounding Upper Air Sounding Lightning Lightning Surface Observations (ASOS) (future) Other?
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Outline NMQ Components Overview Single Radar Process 2-D Radar Mosaic 3-D Radar Mosaic Initial Q2 Development Plans Outlook
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Single Radar Process Reflectivity QC (dynamically evolving effort!) Noise filter Noise filter Sun beam filter Sun beam filter Terrain based QC (hybrid scan) Terrain based QC (hybrid scan) Horizontal texture and vertical structure based QC Temporal continuity based QC Satellite based QC Satellite based QC Dual-pol data (future) Velocity Dealiasing Velocity Dealiasing
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Noise Filter
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Sunbeam Filter
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Horizontal and Vertical Structure Based QC
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To remove the hardware testing pattern: Check sudden increase in echo coverage between consecutive volume scans Temporal Continuity QC
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Effective Cloud Amount
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Single Radar Process (cont.) Reflectivity climatology Reflectivity climatology Brightband Identification Brightband Identification Precipitation typing Precipitation typing (1-good strat rain; 2- bad strat rain; 3-good strat snow; 4- bad strat snow; 5-mixed phase; 6-convective). (1-good strat rain; 2- bad strat rain; 3-good strat snow; 4- bad strat snow; 5-mixed phase; 6-convective). Hybrid scan reflectivity and the associated height Hybrid scan reflectivity and the associated height Composite reflectivity (QC and UnQC) and the associated height Composite reflectivity (QC and UnQC) and the associated height Vertical Profile of Reflectivity (VPR) VPR-adjusted hybrid scan reflectivity
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22 Convective/Stratiform Segregation dBZ > 50 in any bin or, dBZ > 30 at temperatures 30 at temperatures < -10 C or, 1 lightning flash Composite Reflectivity Precip Flags Convective
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Bright Band Identification (BBID) (Gourley and Calvert, 2003, WAF) 3-D Reflectivity Field Find Layer of Higher Reflectivity Vertical Reflectivity Gradient Spatial/Temporal Smoothing
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Precipitation type classification Stratiform rain/snow Precip. type Composite refl.
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Single Radar Process (cont.) 3-D Single Radar Cartesian (SRC) Grid reflectivity (QC’d and UnQC’d) 3-D Single Radar Cartesian (SRC) Grid reflectivity (QC’d and UnQC’d) 3-D SRC reflectivity (QC’d with VPR gap-filling) Multi-scale storm tracking 3-D SRC grid with synchronization
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X Single Radar Cartesian Grid R R = 460km for coastal radars and 300km for other radars. Horizontal grid (~1km x 1km) Vertical grid (31 levels)
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3-D Spherical to Cartesian Transformation (Zhang et al. 2005, JTECH) oo o o + No BB: Vertical linear interpolation BB exists: Vertical and horizontal linear interpolation BB o o + No BB
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Convective Case1: RHI, 263° Raw Interpolated
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Stratiform Case 2: RHI, 0° Raw Interpolated
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Outline NMQ Components Overview Single Radar Process 2-D Radar Mosaic 3-D Radar Mosaic Initial Q2 Development Plans Outlook
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2-D Radar Mosaic Composite reflectivity (QC’d and UnQC’d) and associated height Hybrid scan reflectivity (QC’d, with and without VPR-adjustment) Precipitation type Radar coverage maps (spatial and temporal) Layered composite reflectivity (e.g., the lowest 4 tilts)
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2D Hybrid Scan Refl Mosaic
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2D HYBREF height AGL
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Strat Rain (good) Convective (good) Bright Band (bad) Frozen (bad) 2D Precipitation Type Mosaic
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Outline NMQ Components Overview Single Radar Process 2-D Radar Mosaic 3-D Radar Mosaic Initial Q2 Development Plans Outlook
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3-D Radar Mosaic 3-D multi-radar mosaic grid QC’d QC’d UnQC’d QC’d with VPR gap-filling 2-D derived products: Composite reflectivity and the associated height Composite reflectivity and the associated height Hybrid scan reflectivity and associated height Hybrid scan reflectivity and associated height Hail products (SHI, POSH, MEHS) Hail products (SHI, POSH, MEHS) VIL and VILD VIL and VILD ETOP ETOP Layered composite reflectivity
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Computational Tiles
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Cross Sections from 3-D Mosaic Dallas Hail Storm, 5/5/1995
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Vertical Cross Section Loop (W- E)
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Outline NMQ Components Overview Single Radar Process 2-D Radar Mosaic 3-D Radar Mosaic Initial Q2 Development Plans Outlook
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Q2 Components Radar QPE Satellite QPE Rain gage QPE Multi-sensor QPEs Radar+satellite (& model and sounding) Radar+gage Radar+satellite+gage
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Radar QPE Rain rate Derived from: Hybrid scan reflectivity from 3-D radar mosaic (QC’d, with and without VPR gap-filling) Layer composite reflectivity of the lowest 4 tilts (from 2D radar mosaic) Different Z-R relationships based on 2D mosaic precip type field 1km x 1km, update every 5 min Accumulations (1- to 72-h or longer)
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Z-R relationships Taiwan Oklahoma Convective Oklahoma Stratiform
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Satellite QPE Products from existing algorithms: Hydro (Auto) Estimator GMSRA SCaMPR
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Rain Gauge QPE Individual stations Objective analysis -- gridded gage products (e.g., ADAS) Issues: Bad data Spatial representativeness of gage obs Non-uniform and sparse gage distributions Terrain effects Real-time latency
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Radar-satellite QPE Radar rain rate - satellite Tb regressions Multiple regressions -- one for each weather regimes Initial weather regimes are defined by: Surface temperature zones (hourly RUC surface analysis) Regression using data pairs within a running hourly window Rain rate averaged for each 1 deg Tb bin Derive a dynamic exponential regression to the data in a least square fit sense Various rules to prevent an ill-conditioned regression
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Radar-satellite QPE (Contd.) Satellite rain rate Apply regression curves to the Tb field in each weather regimes and obtain rain rate Distance weighted mean across boundaries between different weather regimes Use rain/no-rain mask (defined by radar obs and satellite) Accumulations (1-72h)
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Satellite/Radar Regression Regression Equation Radar Rainrate Satellite CTT Regresses co-located satellite Tb with stratiform R from radar. One for each weather regimes. Updates regression curves hourly and purges old data Surface Temp
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Generating Multi-sensor Rate Q2 Rainfall Rate Regr. Eqn Regression parameters are used to calibrate cloud-top temperature field by supplying precipitation rates Satellite CTT Surface Temp
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Radar-gage QPE Pre-defined bias regions (radar umbrella? basins? weather regimes?) Regional radar/gage bias adjustment Compute mean radar/gage bias for each bias region Adjust radar QPE using the bias Smoothing over the boundaries between bias regions Point radar/gage bias adjustment Compute radar/gage bias at each gage station Objective analysis of the point biases Adjust radar QPE using the gridded bias field Bias is based on hourly accumulation Adjustment is performed in real-time dynamically
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Outline NMQ Components Overview Single Radar Process 2-D Radar Mosaic 3-D Radar Mosaic Initial Q2 Development Plans Outlook
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Outlook Radar QPE Improve radar data QC VPR/range correction Additional data streams Continue improving precip typing including identification of warm rain process More adaptive Z-R relationships Gage QPE Improved gage QC Adaptive influence of radius for objective analysis Non-uniform spatial distributions Terrain effects (mountain mapper?)
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Precipitation typing Warm/cold rain Cold rain echo core (dbZ) Warm rain echo core (dbZ) -10°C time height time height 40 50 60 50
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New Data Streams (e.g. TDWR) Better coverage at lower atmosphere Higher spatial resolution near urban areas
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Outlook ( Contd.) Radar-satellite QPE Refine weather regimes for satellite-radar regressions Multi-variable regression using multi-spectral satellite data (SCaMPR concepts) Systematic verification Extensive case studies from different weather regimes Real-time verification of all products Quantification of uncertainties in different QPEs
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6/29/2005 Q2 Workshop, Norman, OK THANK YOU! Jian.zhang@noaa.gov
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