1. BUFKIT for Balloonists Jay Trobec, Ph.D. KELOLAND TV Sioux Falls, SD jaytrobec.com

2. Questions we will answer How do I install the free software on my computer? What is a computer model? What does BUFKIT tell us about… – Winds aloft? – Temperatures? – Inversions? – Fog/Precipitation forecasting?

3. How do I install it on my computer?

4. Computer models Give us an approximation of the expected state of the atmosphere They do not “forecast” the weather – interpretation is required Three models are beneficial to balloonists, and can be displayed with BUFKIT software – NAM (North American Mesoscale) – GFS3 (Global Forecast System) – RUC (Rapid Update Cycle)

5. BUFKIT data

6. BUFKIT visual display

7. NAM (also called the WRF) Model Created at 0z (6 pm CST), 6z (midnight CST), 12z (6 am CST), and 18z (noon CST) 12 km resolution 1 hr increments 84 hrs

8. GFS Model Created at 0z (6 pm CST), 6z (midnight CST), 12z (6 am CST), and 18z (noon CST) 0.5 deg lat/lon 3 hr increments 180 hrs

9. RUC (also called RAP or HRRR) Model Created every hour 13 km resolution 18 hrs

10. BUFKIT Temperature/Wind Display

11. BUFKIT Overview Wind Display

12. Overview Clouds Display Sky Box Plotted Implied.00 -.09 none Clear.10 -.24 Single Cross Hatched Few.25 -.49 Double Cross Hatched Scattered.50 -.74 Gray Broken.75 - 1.00 White Overcast

13. Environmental Lapse Rate (ELR) Decrease of temperature with altitude in a stationary atmosphere 0.5°C/100 meters 3.5°F /1000 feet 1500 ft: 54.8° 1000 ft: 56.5 1000 ft: 56.5° 500 ft: 58.3 500 ft: 58.3° Ground: 60°

14. Subsidence, sinking air under High pressure Temperature Inversion Thin layer in the atmosphere in which air temperature increases with height Caused by: Warm Fronts or Cold Fronts

15. Subsidence Inversion

16. Radiational Inversion

17. Effects of Inversion Speed of ascent slows when rising through subsidence layer

18. Effects of Inversion Speed of descent slows when descending through layer

19. Effects of Inversion Winds often have different directions/speeds above and below an inversion

20. Inversion display on BUFKIT

21. Fog forecasting BUFKIT utilizes “crossover temperature” technique developed by UPS Also assesses change in humidity with height, and atmospheric stability Technique is designed for radiational fog, not advection or other types of fog