NUMERICAL WEATHER PREDICTION IN VERY SHORT TERM WIND FORECASTING 1 Zoltan Toth Global Systems Division NOAA/OAR/ESRL Acknowledgements: Forecast Applications Branch

HISTORICAL OVERVIEW & STATUS T-LAPS – Terminal Local Analysis & Prediction System –Fine scale (5 km?) analysis of 3D winds around 40 terminals since early 1990s - ITWS –Revolutionary solution at the time –Still used in operations today (20-year old system) –Statistical nowcasting tools have limitations NWS operational systems today (NAM, RAP) –~ 12 km resolution Analysis has insufficient detail Forecast does not resolve features of interest

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WHAT HAS CHANGED User needs - Demand for analyses and forecasts that are –More accurate –More detailed –3D gridded –Supporting specific decision tool Scientific readiness – Advances in –Data assimilation - 4DVAR, hybrid, multiscale methods –Numerical modeling – Boundary layer, microphysics, etc –Ensembles to quantify uncertainty for decision making Observing systems – New instruments / platforms –Various profilers, radiometrics Computing –Massively parallel architectures, Graphical Processing Units, Fine Grain computing, etc

5 TRADITIONAL 3DVAR, LAPS, & VAR-LAPS LAPS VAR-LAPS TRUTH 3DVAR with small-scale covariance 3DVAR with large-scale covariance 3DVAR Medium- scale

NEW REVOLUTION FOR 0-3 HOUR FORECASTS? NWP-based very short term forecasting possible Paradigm shifts due to major advances in 4 areas –From statistically based nowcasting tools & subjective methods to Statistically enhanced NWP guidance –From disjoint efforts focusing on different AIVs to Holistic approach based on gridded NWP guidance –Same core system with specific end user applications serving multiple users Vision –1 km resolution national NWP-based system Analysis with 5-min update frequency Forecast for 0-3 hours, with 15-min frequency Statistical processor to reduce systematic errors and blend with latest obs

WARN ON FORECASTING (WOF) – ARE WE GETTING THERE? On occasion, variational LAPS superior to advection and persistence Variational LAPS

WHAT’S NEEDED? NWP-based very short term forecasting Observations –Use all existing observations –Asses additional needs – Observing System Simulation Experiments –Deploy systems near terminals – focus on lower atmosphere NWP data assimilation –Focus on fine scales – multiscale methods –4-DVAR –Dynamical & physical balances for forecast initialization Numerical forecasting –Boundary layer & microphysics parameterizations –Variable resolution models for enhancements near terminals –Ensembles to quantify forecast uncertainty

TO MAKE & COMPLETE THE FORECAST Computing –GPU or other fine grain solutions Statistical postprocessing –Modify / reconfigure existing nowcasting tools to use NWP guidance –Bayesian methods to fuse predictive information from NWP guidance Latest observations Conditional climatology User applications – Aviation –Wind compression –Runway wind shifts –Visibility –Icing –Turbulence –Precipitation incl type –Lightning –Convection

Cloud / Reflectivity / Precip Type (1km analysis) - Loop DIA Obstructions to visibility along approach paths

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APPLICATIONS / NEEDS - NWS High quality digital TAF – WFOs Wind compression / approach decisions – CWSUs Automated frontal analysis – NCEP/HPC Severe weather initiation – NCEP/SPC Fire Weather – WFOs Marine forecasting - WFOs

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Variational LAPS, Mar. 23, Z Front analysis for the case of Divergence field

FIRE WEATHER APPLICATION Incident report Regional scale data Downscaling Fine Scale Forecast Fill in details Variational LAPS 5

Example of Downscaling: Four Mile Canyon Fire 7 Initial input at 8km res Surface U wind (colors) NORTH-SOUTH EAST – WEST (km) Contour lines: topography Downscaled output at 1km resolution Finer details in wind in response to high resolution terrain EAST – WEST (km)

APPLICATIONS / NEEDS – DoD & DHS Dispersion forecasting – DHS Precision drops – US Army Toxic air alerts for rocket launches – USAF – RSA Nuclear pollution tracking – USAF – AFTAC Dispersion – toxic plume prediction – DHS – GTAS Theater forecasts

LAPS Applications: High Resolution LAPS is used to initialize WRF model runs and other systems around the globe Personnel: Linda Wharton, Isidora Jankov, Steve Albers, Dan Birkenheuer - FAB LAPS RSA (Range Standardization And Automation System) AFTAC (Air Force Technical Applications Center) DFWSEANYCKSC WRF Ensemble WRF WRF WRF PADS AWIPS II

RSA - Range Standardization and Automation Weather Support System … to support dispersion models predicting where toxic plumes from rocket launches will go. … to provide high resolution weather data to help with launch decisions. OAR/ESRL/GSD/Forecast Applications Branch

22 PADS - Precision Air-Drop System Geo-Targeted Alerting System Provides air dispersion and toxic plume information along with NOAA meteorological and environmental data to state and local emergency management agencies. AFTAC - Air Force Technical Applications Center Provides nuclear treaty monitoring, nuclear event detection and analyzes disturbing events for nuclear identification.

BACKGROUND

24 LAPS USER BASE NOAA – ~120 WFOs (via AWIPS), ARL, NESDIS Other US Agencies – DHS, DoD, FAA, CA DWR, GA Air Qual. Academia – Univ of HI, Athens, Arizona, CIRA, UND, McGill Private Sector – Weather Decision Tech., Hydro Meteo, – Precision Wind, Vaisala, Telvent International agencies (10+ countries) – KMA, CMA, CWB, Finland (FMI), Italy, Spain, – BoM (Australia), Canary Islands, HKO, – Greece, Serbia, Nanjing Inst. of Met.

25 LAPS SCIENTIFIC IMPACT – REFEREED PAPERS 30 refereed publications by GSD/NOAA 1-2 refereed papers per year 391 citations in refereed papers ~ 40 / year recently

LAPS NOAA, local analysis and prediction system –Query period: Papers 4163 Citations –Cites/year: –Cites/paper: 9.64/0.0/0 (mean/median/mode) –Cites/author: –Papers/author: LAPS SCIENTIFIC IMPACT – ALL PUBLICATIONS