1. Weather Radar Overview Jody James Senior Forecaster Aviation Safety Counselor National Weather Service, Lubbock

2. Topics To Cover Basics of Radar Onboard versus Datalink Radar Radar Data Interpretation Dangerous Weather Signatures Radar Data Available on the Internet Questions

3. Radar Basics Pulse of energy emitted from the transmitter Energy strikes rain, hail, birds, bugs, dust, smoke, etc. and some of the energy is backscattered to the radar receiver Motions of the target are detected as either moving away from or toward the radar (“Doppler” effect) Images from the University of Illinois WW2010 Project.

4. Onboard Radar Disadvantages Huge Beam Widths (10 inch), 10 deg bw Attenuation Radome Problems StormScope

5. Satellite Radar (Datalink) based on WSR-88D (Nexrad) Weather Surveillance Radar, 1988, Doppler NEXRAD – Next Generation Weather Radar

6. NWS WSR-88D Radar 750 Kw Peak Power Narrow Beam Width Attenuation not a problem Automated System Products Include: Reflectivity Velocity Precip Accumulation Storm Tracking Info

7. Reflectivity Intensity Scales This is a display of echo intensity (reflectivity) measured in dBZ (decibels of Z, where Z represents the energy reflected back to the radar). "Reflectivity" is the amount of transmitted power returned to the radar receiver.

8. Radar Data Interpretation Is rain reaching your altitude? Are echoes real or false (AP)? Check time of radar data Monitor movement Full resolution mosaic image – (weather.radar.gov)

9. Datalink Radar - Handheld (based on NWS WSR-88D data) Example – Garmin GPS 495 XM WX (subscription) depicts precipitation intensity, lightning, etc.

10. Datalink Radar based on WSR-88D Example – Garmin GPS 495 Lightning Echo Tops

11. Datalink Weather (Panel Mount) Example – Garmin GMX 200 Multifunction Display Graphical weather depictions including NEXRAD, METARs, TAFs, TFRs, winds aloft, echo tops, precipitation type at the surface, lightning strikes, storm-cell data, AIRMETs, and SIGMETs can be received and displayed regardless of altitude.

12. Severe Weather Signatures

14. Beware of “Bad Shapes” Bow Shapes or Bowed Out Lines

15. Severe Weather Signatures

16. Beware of “Bad Shapes” Hook

17. Severe Weather Signatures

18. Beware of “Bad Shapes” Pendant or Finger

19. Beware of “Bad Shapes” Steep Precipitation Gradients

20. Other “Bad Shapes” Assymetric Strong Shear Finger Can Precede Hooks Scalloped Edge Strong Inflow/Outflow Winds Arrow Strong Winds Aloft

21. Radar Data Sources on Internet NWS Websites – radar.weather.gov AOPA Website (members) College of DuPage (weather.cod..edu) Your favorite vendor (Inflight)

22. Weather Radar Overview Thank You! Questions?