1. Aviation/Turbulence Forecasting

2. Aviation Weather Center (AWC) National Weather Service office Turbulence, flight rules, upper level progs

3. SIGWX Charts (High-level)

4. Streamlines at 36,000 ft. (other levels available)

8. Convective SIGMETS

12. Forecasting Aviation Turbulence Complicated –Topography –Convection –Mechanical forcing –Microscale Cannot be resolved by NWP models Approach: Analyze synoptic patterns that create or allow turbulence

13. Graphical Turbulence Guidance (GTG) Developed by National Center for Atmospheric Research (NCAR) Uses RUC (Rapid Update Cycle) 20 km grids and observations of turbulence/lightning Combines 11 different turbulence forecasting tools through a weighting function Produces upper-level clear-air turbulence (CAT) prediction Output is a number from 0-1

14. This value is used in coordination with other observations to produce a 3,6,9, and 12 hour forecast of turbulence

15. Turbulence Guidance

16. How Good is GTG? Kelsch et al., 2004, AMS

18. Terminal Aviation (Aerodrome) Forecasts (TAFs) Surface forecast for hundreds of airport terminals around the country –Use METAR code –Produced by a human (not always at the reporting site) –Can be more accurate than NWP models Local effects

19. TAF KAVL 021120Z 021212 34010G20KT P6SM SCT025 BKN250 FM1500 35008KT P6SM SCT040 BKN100 FM0000 VRB04KT P6SM BKN035 FM0800 16005KT P6SM BKN025 Station Report issued 2 nd day of the month (April 2) at 1120Z Valid for 12Z today thru 12Z tomorrow Forecast Wind at 12Z today 6+ miles visibility Sky Condition at 12Z 15Z forecast today 00Z forecast tomorrow 08Z forecast tomorrow Line that begins with “TEMPO” indicates temporary or occasional conditions (e.g. fog, visibility) within a time period specified TEMPO 0912 2SM BR OVC 010

21. Flight Path Tool http://adds.aviationweather.gov/flight_path/