4 WMO WEATHER FORECASTING RANGES NowcastingA description of current weather parameters and 0 -2 hours description of forecasted weather parametersVery short-rangeUp to 12 hours description of weather parametersShort-rangeBeyond 12 hours and up to 72 hours description of weather parametersMedium-rangeBeyond 72 hours and up to 240 hours description of weather parametersExtended-rangeBeyond 10 days and up to 30 days description of weather parameters, usually averaged and expressed as a departure from climate values for that period.Long-rangeMonthly outlookThree month or 90 day outlookSeasonal outlookFrom 30 days up to two yearsDescription of averaged weather parameters expressed as a departure (deviation, variation, anomaly) from climate values for that month (not necessarily the coming month).Description of averaged weather parameters expressed as a departure from climate values for that 90 day period (not necessarily the coming 90 day period).Description of averaged weather parameters expressed as a departure from climate values for that season.Climate forecastingClimate variability predictionClimate predictionBeyond two yearsDescription of the expected climate parameters associated with the variation of inter-annual, decadal and multi-decadal climate anomalies.Description of expected future climate including the effects of both natural and human influences.
5 COMPONENTS of FORECAST SYSTEM 1. Observing system2. Telecommunication system3. Computer system4. Data assimilation5. Model6. Postprocessing
9 The system of equations (conservation laws applied to individual parcels of air) (from E.Kalnay) V. Bjerknes (1904) pointed out for the first time that there is a complete set of 7 equations with 7 unknowns that governs the evolution of the atmosphere:conservation of the 3-dimensional momentum (equations of motion),conservation of dry air mass (continuity equation),the equation of state for perfect gases,conservation of energy (first law of thermodynamics),equations for the conservation of moisture in all its phases.They include in their solution fast gravity and sound waves, and therefore in their space and time discretization they require the use of smaller time steps, or alternative techniques that slow them down. For models with a horizontal grid size larger than 10 km, it is customary to replace the vertical component of the equation of motion with its hydrostatic approximation, in which the vertical acceleration is neglected compared with gravitational acceleration (buoyancy). With this approximation, it is convenient to use atmospheric pressure, instead of height, as a vertical coordinate.
12 Coordinate systems: p, sigma, z, eta, hybrid Models of atmosphere: Steps: global km, local 7-12 km; Methods: splitting, semi-Lagrangian scheme (23), ensembles, nonhydrostatic, gridsData assimilation: (4)D-Var, Kalman filterReanalyses NCEP / NCAR USA years (1948-…; T62L28~210km) Reanalyses-2 (ETA RR 32 km, 45 layers) ECMWF ERA-15 (TL106L31~150km, ), ERA-40 (TL159L60~120km, 3D-Var, mid )FEATURES OF INFORMATION AND COMPUTATIONAL TECHNOLOGIES IN ATMOSPHERIC SCIENCES
13 Modern and Possible further development computational technologies ensemble simulation
14 ECMWF: FORECASTING SYSTEM - DECEMBER 2003 Model:Smallest half-wavelength resolved:40 km (triangular spectral truncation 511)Vertical grid: hybrid levels (top pressure: 10 Pa)Time-step: minutesNumerical scheme: Semi-Lagrangian, semi- implicit time-stepping formulation.Number of grid points in model:20,911,680 upper-air, 1,394,112 in land surface and sub- surface layers. The grid for computation of physical processes is a reduced, linear Gaussian grid, on which single- level parameters are available. The grid spacing is close to 40km.Variables at each grid point (recalculated at each time-step):Wind, temperature, humidity, cloud fraction and water/ ice content, ozone content (also pressure at surface grid-points)Physics:orography (terrain height and sub-grid-scale), drainage, precipitation, temperature, ground humidity, snow-fall, snow-cover & snow melt, radiation (incoming short-wave and out-going long-wave), friction (at surface and in free atmosphere), sub-grid-scale orographic drag - gravity waves and blocking effects, evaporation, sensible & latent heat flux, oceanic waves.
15 ECMWF: FORECASTING SYSTEM - DECEMBER 2003 Data Assimilation:Analysis:Mass & wind (four-dimensional variational multi- variate analysis on 60 model levels)Humidity (four-dimensional variational analysis on model levels up to 250 hPa)Surface parameters (sea surface temperature from NCEP Washington analysis, sea ice from SSM/I satellite data), soil water content, snow depth, and screen level temperature and humidityData used:Global satellite data (SATOB/AMV, (A)TOVS, Quikscat, SSM/I, SBUV, GOME, Meteosat7 WV radiance),Global free-atmosphere data (AIREP, AMDAR, TEMP, PILOT, TEMP/DROP, PROFILERS),Oceanic data (SYNOP/SHIP, PILOT/SHIP, TEMP/SHIP, DRIBU),Land data (SYNOP). Data checking and validation is applied to each parameter used. Thinning procedures are applied when observations are redundant at the model scale.
16 Nonhydrostatic models the Penn State/NCAR Mesoscale Model (e.g., Dudhia, 1993),the CAPS Advanced Regional prediction System (Xue et al, 1995),NCEP's Regional Spectral Model (Juang et al, 1997),the Mesoscale Compressible Community (MCC) model (Laprise et al, 1997),the CSU RAMS Tripoli and Cotton (1980),the US Navy COAMPS (Hodur, 1997).
18 WRF Development Teams Courtesy NCAR WG1 WG3 WG6 WG12 WG5 WG4 WG7 WG9
19 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) Model Physics in High Resolution NWPPhysics“No Man’s Land”kmCumulus ParameterizationResolved ConvectionLESPBL ParameterizationTwo Stream Radiation3-D RadiationFrom Joe Klemp, NCAR (Bad Orb, )
20 Weather Research and Forecasting Model Goals: Develop an advanced mesoscale forecast and assimilation system, and accelerate research advances into operations36h WRF Precip ForecastAnalyzed Precip27 Sept. 2002Collaborative partnership, principally among NCAR, NOAA,DoD, OU/CAPS, FAA, and university communityMulti-agency WRF governance; development conductedby 15 WRF Working GroupsSoftware framework provides portable, scalable code withplug-compatible modulesOngoing active testing and rapidly growing community useOver 1,400 registered community users, annualworkshops and tutorials for research communityDaily experimental real-time forecasting at NCAR ,NCEP, NSSL, FSL, AFWA, U. of IllinoisOperational implementation at NCEP and AFWA in FY04From Joe Klemp, NCAR (Bad Orb, )
21 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) Hurricane IsabelNOAA –17 AVHRR 13 Sep 03 14:48 GMTFrom Joe Klemp, NCAR (Bad Orb, )
22 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) Hurricane Isabel Track18/1700Z4 km WRFInitialized 17/0000Z10 km WRFInitialized 15/1200ZFrom Joe Klemp, NCAR (Bad Orb, )
23 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) Hurricane Isabel 3 h Precip ForecastWRF Model10 km grid5 day forecastInitialized:12 UTC 15 Sep 03From Joe Klemp, NCAR (Bad Orb, )
24 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) 48 h Hurricane Isabel Reflectivity ForecastInitialized 00 UTC 17 Sep 03Radar Composite4 km WRF forecastFrom Joe Klemp, NCAR (Bad Orb, )
25 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) Hurricane Isabel Reflectivity at Landfall18 Sep ZRadar Composite41 h forecast from 4 km WRFFrom Joe Klemp, NCAR (Bad Orb, )
26 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) Hurricane Isabel Surface-Wind ForecastWRF Model4 km grid2 day forecastInitialized:00 UTC 17 Sep 03From Joe Klemp, NCAR (Bad Orb, )
27 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) WRF Mass Coordinate CoreTerrain-following hydrostatic pressure vertical coordinateArakawa C-grid, two-way interacting nested grids (soon)3rd order Runge-Kutta split-explicit time differencingConserves mass, momentum, dry entropy, and scalarsusing flux form prognostic equations5th order upwind or 6th order centered differencingfor advectionPhysics for CR applications: Lin microphysics, YSU PBL,OSU/MM5 LSM, Dudhia shortwave/RRTM longwaveradiation, no cumulus parameterizationFrom Joe Klemp, NCAR (Bad Orb, )
28 From Joe Klemp, NCAR (Bad Orb, 23-27.10.03 2003) Model Configuration for 4 km GridDomain2000 x 2000 km, 501 x 501 grid50 mb top, 35 levels24 s time stepInitializationInterpolated from gridded analysesBAMEX: 40 km Eta CONUS analysisIsabel: 1o GFS global analysis (~110 km)Computing requirements128 Processors on IBM SP Power 4 RegattaRun time: 106 min/24h of forecastFrom Joe Klemp, NCAR (Bad Orb, )
29 North American Early Guidance System 5/31/20096 km aerosols in radiative transfer & reflectivity6 km WRF aerosols5/31/20087 km absorption scattering in radiative transfer7 km WRF improved physics5/31/20059 km AIRS, GOES imagery & move top to 2mb9 km NMM 2mb hourly output5/31/20068 km WRF 4DDA8 km WRF5/31/20105 km NPP, advanced 4DDA, NPOESS, IASI & air quality5 km WRF L1002/28/200410 km hourly update & improved background error cov.10 km Meso Eta improved physics9/30/200212 km 3DVAR radial velocity12 km Meso EtaDateData AssimilationPrediction Model
30 Global Forecast System (GFS) 5/31/2009NPP, integrated SST analysis40 km / L805/31/2008Aerosols in radiative transfer, GIFTS5/31/20053-D Background error covariance, cloud analysis, minimization45 km / L645/31/2006Absorption / scattering in radiative transfer45 km / L64 + improved microphysics5/31/2010Advanced 4DDA, NPOESS, IASI + air quality35 km / L1002/28/2004Grid point version, AIRS, GOES imageryT-254 / L64 add 2 passive tracers9/30/20023D-VAR, AMSU-B, QuikscatT-254 / L64DateData AssimilationPrediction Model
31 Timeline for WRF at NCEP North American WRF: Operational in FY05Hurricane WRF: Operational in FY06Rapid Refresh (RUC) WRF (hourly): Operational in FY07WRF SREF : Operational in FY07Others? (Fire Wx, Homeland Security, etc.) using best WRF deterministic model
32 http://www. metoffice. com/research/nwp/numerical/unified_model/index The Unified ModelThe Unified Model is the name given to the suite of atmospheric and oceanic numerical modellingsoftware developed and used at the Met Office.The formulation of the model supports global and regional domains and is applicable to awide range of temporal and spatial scales that allow it to be used for both numericalweather prediction and climate modelling as well as a variety of related research activities.The Unified Model was introduced into operational service in 1992.Since then, both its formulation and capabilities have been substantially enhanced.New Dynamics A major upgrade to the Met Office Global Numerical Weather Prediction model was implementedon 7th August 2002.Submodels The Unified Model is made up of a number of numerical submodels representing different aspects ofthe earth's environment that influence the weather and climate.Like all coupled models the Unified Model can be split up in a number of different ways,with various submodel components switched on or off for a specific modelling application.The Portable Unified Model (PUM) A portable version of the Unified Model has also been developed suitable for runningon workstations and other computer systems.
33 The Met Office Global Numerical Weather Prediction model The Met Office Global Numerical Weather Prediction modelwas implemented on 7th August 2002.The package of changes was under trial for over a year and is known as "New Dynamics".This document details some of the key changes that are part of the New Dynamics package.Non-hydrostatic model with height as the vertical co-ordinate.Charney-Philips grid-staggering in the vertical,Arakawa C-grid staggering in the horizontal,Two time-level, semi-Lagrangian advection and semi-implicit time stepping.Edwards-Slingo radiation scheme with non-spherical ice spectral filesLarge-scale precipitation includes prognostic ice microphysics.Vertical gradient area large-scale cloud scheme.Convection with convective available potential energy (CAPE) closure,momentum transports and convective anvils.A boundary-layer scheme which is non-local in unstable regimes.Gravity-wave drag scheme which includes flow blocking.GLOBE orography dataset.The MOSES (Met Office Surface Exchange Scheme) surface hydrologyand soil model scheme.Predictor-corrector technique with no extraction of basic state profile.Three-dimensional Helmholtz-type equation solved using GCR technique.
34 Météo-France 2003 statusThe operational forecast system at Météo-France is based on two different numerical applications of the same code ARPEGE-IFS,2. additional code to build the limited area model ALADIN.The ARPEGE-IFS has been developed jointly by Météo-France and ECMWF (ARPEGE is the usual name in Toulouse and IFS - in Reading):ECMWF model for medium range forecasts (4-7 days)a Toulouse variable mesh version in for short range predictions (1-4 days)The ALADIN library has been developed jointly by Météo-France and the national meteorological or 14 hydrometeorological services: Austria, Belgium, Bulgaria, Croatia, Czech Republic, Hungary,Moldova, Morocco, Poland, Portugal, Romania, Slovakia,Slovenia, Tunisia.
35 40(35) 325 35 325 DWD FORECAST SYSTEM Local model (LM) Global model (GME)DWD FORECAST SYSTEM
41 Further Development of the Local Systems LME and LMK 2003 to 2006 LME: Local model LM for whole of Europe; mesh size 7 km and 40 layers; h forecasts from 00, 12 and 18 UTC.LMK: LM-”Kürzestfrist”; mesh size < 3 km and 50 layers; 18-h forecasts from 00, 03, 06, 09, 12, 15, 18, 21 UTC for Germany with explicit prediction of deep convection.1. Data assimilation2 Q 2005Use satellite (GPS) and radar data (reflectivity, VAD winds)1 Q 2006Use European wind profiler and satellite data
42 Further Development of the Local Systems LME and LMK 2003 to 2006 2. Local modelling2 Q 2004Increase model domain (7 km mesh) from 325x325 up to 753x641 gridpoints (covering whole of Europe), 40 layers3 Q 2005New convection scheme (Kain-Fritsch ?)
44 LMK: LM-KürzestfristModel-based system for nowcasting and very short range forecastingGoals:Prediction of severe weather on the mesoscale.Explicit simulation of deep convection.Method:18-h predictions of LM initialised every three hours, mesh size < 3 kmUsage of new observations:SYNOP: Every 60 min, METAR: Every 30 min,GPS: Every 30 min, VAD winds: Every 15 min,Reflectivity: Every 15 min, Wind profiler: Every 10 min,Aircraft data.
45 LMK: A new 18-h forecast every three hours 000306091215182100(UTC)LMK: A new 18-h forecast every three hours
46 High-resolution Regional Model HRM Operational NWP Model at 13 services worldwideHydrostatic, (rotated) latitude/longitude gridOperators of second order accuracy7 to 28 km mesh size, various domain sizes20 to 35 layers (hybrid, sigma/pressure)Prognostic variables: ps, u, v, T, qv, qc, qiSame physics package as GMEProgramming: Fortran90, OpenMP/MPI for parallelizationFrom 00 and 12 UTC: Forecasts up to 78 hoursLat. bound. cond. from GME at 3-hourly intervals
47 General structure of a regional NWP system TopographicaldataGraphicsVisualizationMOSKalmanRegionalNWPModelInitial data(analysis)Direct modeloutput (DMO)ApplicationsWave model,TrajectoriesLateralboundary dataVerificationDiagnostics
48 Short Description of the High-Resolution Regional Model (HRM) Hydrostatic limited-area meso- and meso- scale numerical weather prediction modelPrognostic variablesSurface pressure psTemperature TWater vapour qvCloud water qcCloud ice qiHorizontal wind u, vSeveral surface/soil parametersDiagnostic variablesVertical velocity Geopotential Cloud cover clcDiffusion coefficients tkvm/h
49 Current operational users of the HRM Kenya, National Meteorological ServiceOman, National Meteoro-logical Service (DGCAM)Romania, National Meteoro-logical & Hydrological ServiceSpain, National Met. InstituteUnited Arab Emirates, National Met. InstituteVietnam, National Meteoro-logical & Hydrological Service; Hanoi UniversityBrazil, Directorate of Hydrography & NavigationBrazil, Instituto Nacional de MeteorologiaBulgaria, National Meteoro-logical & Hydrological ServiceChina, Guangzhou Regional Meteorological CentreIndia, Space Physics Lab.Israel, Israel Meteorological ServiceItaly, Italian Meteorological Service
50 Numerics of the HRM Regular or rotated latitude/longitude grid Mesh sizes between 0.25° and 0.05° (~ 28 to 6 km)Arakawa C-grid, second order centered differencingHybrid vertical coordinate, 20 to 35 layersSplit semi-implicit time stepping; t = 150s at = 0.25°Lateral boundary formulation due to DaviesRadiative upper boundary condition as an optionFourth-order horizontal diffusion, slope correctionAdiabatic implicit nonlinear normal mode initialization
51 Physical parameterizations of the HRM -two stream radiation scheme (Ritter and Geleyn, 1992) including long- and shortwave fluxes in the atmosphere and at the surface; full cloud - radiation feedback; diagnostic derivation of partial cloud cover (rel. hum. and convection)Grid-scale precipitation scheme including parameterized cloud microphysics (Doms and Schättler, 1997)Mass flux convection scheme (Tiedtke, 1989) differentiating between deep, shallow and mid-level convectionLevel-2 scheme of vertical diffusion in the atmosphere, similarity theory (Louis, 1979) at the surfaceTwo-layer soil model including snow and interception storage; three-layer version for soil moisture as an option
52 Computational aspects of the HRM Fortran 90 and C (only for Input/Output: GRIB code)Multi-tasking for shared memory computers based on standard Open-MPEfficient dynamic memory allocationNAMELIST variables for control of modelComputational cost: ~ 3100 Flop per grid point, layer and time stepInterface to data of the global model GME available providing initial and/or lateral boundary dataBuild-in diagnostics of physical processesDetailed print-out of meteographs
55 Further Development of the HRM 2003 to 2006 An MPI version of HRM for Linux PC Clusters, developed by Vietnam, is available to all HRM users since July 2003.A 3D-Var data assimilation scheme developed by Italy will be available to experienced HRM users early 2004.The physics packages in GME and HRM will remain exactly the same.The interaction between the different HRM groups should be intensified.A first HRM User’s Meeting will take place in Rio de Janeiro (Brazil) in October 2004.
59 TASKS for the DWD in the EFFS 1) Run the complete assimilation-forecast system for GME and LM for the three historical flood events for a period of roughly 2 weeks for each flood event.2) Perform for the three flood events high resolution analyses of 24h precipitation heights on the basis of surface observations.3) Develop a prototype-scheme for near real-time 24h precipitation analysison the basis of Radar-data and synoptic precipitation observations.In addition to these tasks the operational model results according to task 1)for the period of the Central European flood were retrieved from the archivesand supplied to the project ftp-server.
64 NWP Systems (now and plans) (Computers, Göbal and Local Models) 20022003200420052006ECMWF0.96 TfTL511 (40km) L6010 Tf20 Tf TL511(40km) L60TL799(25km) L91DWD1.92 Tf60km L317 km L352.88 Tf40km L407 / 2 km L3518-28 Tf30km L45NCEP7.3 TfT170(80km) L4212km L60T254(50km) L6415.6 TfTL611(40km) L428 km28 Tf 2007:G 30kmL kmJMA Japan0.768 TfT106(120km) L4020 / 10 km L40TL319(60km) L426 Tf5 km L5020 Tf 2007: TL959(20km) L60CMA China0.384 TfT213(60km) L3125 km L203.84 Tf ?15 km2008: 5 kmHMC Russia35 GfT85(150km) L3175 km L30T Tf ?T169(80km) L31
65 ECMWF: EQUIPMENT IN USE (end of 2003) Computer equipment being readied for operational use
66 Central Computer System (CCS) 2500 TB84 TB2752 MBGHzPhase II6/20041250 TB42 TB1408 MBGHzPhase I9/2002200 TB30 TB1216 MBMHzCurrent 2001Tape StorageDisk SpaceMemoryProcessorsClock SpeedPhase /DateBut what are we going to do if we have not CCS?
67 Result of V.Galabov (Bulgaria) experiments with different PCLINUX (Red Hat 7.3)PGI Workstation 4.0 (Portland Group Fortran and C++)HRM DWD (hydrostatic High Resolution Model)93 x 73, 31 Layers,grid spacing (14 km),forecast for 48 hoursAMD Duron 1300MHz Mb PC 133 SDRAM minAMD Athlon XP MHz Mb DDR266 RAM minPentium GHz Mb DDR333 SDRAM minIntel Xeon Workstation1 processor GHz Mb RDRAM PC min2 processors 2.4 GHz Mb RDRAM PC min
68 program TestOMP end program TestOMP integer k, n, tid, nthreads, max_threads, procslogical dynamic, dynamicdouble precision d (5000)===== call gettim (hrs1,mins1,secs1,hsecs1) call getdat (year,month,day)max_threads = OMP_GET_MAX_THREADS()procs = OMP_GET_NUM_PROCS()dynamic = OMP_GET_DYNAMIC()nested = OMP_GET_NESTED()!$OMP PARALLEL PRIVATE (NTHREADS, tid, n, k)tid = OMP_GET_THREAD_NUM()nthreads = OMP_GET_NUM_THREADS()!$OMP DO SCHEDULE (STATIC, 5000)do n = 1 , 10000do k = 1, 5000d(k) = sin (dble(k+n))**2 + cos (dble(k+n))**2end do!OMP END DO!$OMP END PARALLEL===== call gettim (hrs2,mins2,secs2,hsecs2) call getdat (year,month,day)end program TestOMP
70 The future (from E.Kalnay) An amazing improvement in the quality of the forecasts based on NWP guidance. From the active research currently taking place, one can envision that the next decade will continue to bring improvements, especially in the following areas:Detailed short-range forecasts, using storm-scale models able to provide skillful predictions of severe weather.More sophisticated methods of data assimilation able to extract the maximum possible information from observing systems, especially remote sensors such as satellites and radars.Development of adaptive observing systems, where additional observations are placed where ensembles indicate that there is rapid error growth (low predictability).Improvement in the usefulness of medium-range forecasts, especially through the use of ensemble forecasting.Fully coupled atmospheric-hydrological systems, where the atmospheric model precipitation is appropriately downscaled and used to extend the length of river flow prediction.More use of detailed atmosphere-ocean-land coupled models, where the effect of long lasting coupled anomalies such as SST and soil moisture anomalies leads to more skillful predictions of anomalies in weather patterns beyond the limit of weather predictability (about two weeks).More guidance to government and the public on areas such as air pollution, UV radiation and transport of contaminants, which affect health.An explosive growth of systems with emphasis on commercial applications of NWP, from guidance on the state of highways to air pollution, flood prediction, guidance to agriculture, construction, etc.