1. Weather Information for the Ballooning Community Jennifer McNatt Lead Forecaster National Weather Service Tampa Bay Office

2. Today’s Overview Meteorology Review Forecasting 101 – Current data (soundings, observations, radar) – Model data – Forecasts (TAFs, meteograms) Sources for Weather Information

3. Meteorology Review Upper Level Patterns – What “drives” weather systems

4. Highs and Lows Determine surface wind direction and speed Precip chances Cloud cover

5. Meteorology Review - Winds Pressure gradient – Tight = faster winds Follow isobars, but also flow from higher to lower pressures

6. Local Winds Smaller-scale winds caused by local effects. – Seabreezes – Differential Heating – Convective Outflow – Inversions/Boundary Layer

7. Seabreezes During a clear day... sunshine heats the land to a greater extent than the water. Warm air over the land rises and is replaced by cooler, moister, marine air.

9. At Night… Opposite processes occur

10. Differential Heating

11. Convective Outflows Doesn’t have to be from a thunderstorm Range from an increase in a few knots to 100+kts – Rapid change in wind direction

12. Inversions/Boundary Layer Especially pertinent to early AM flights – Colder layer near the surface – Gets “cut-off” from layer above it Leads to stronger winds in layer above Winds mix down to surface after sunrise

13. TemperatureDewpoint

14. Forecasting 101 To know what’s going to happen in the future, you have to know what’s going on now…

15. Observing the Weather ASOS - Automated Surface Observing System Rain Temp & Dew Point Precip type and intensity Wind Direction and Speed Data Unit Visibility Pressure measured at the Tower or other location nearby.

16. ASOS 569 FAA sponsored sites 313 NWS sponsored sites Non-stop weather information Computer generated voice broadcasts Using FAA VHF ground-to-air radio or appended to ATIS broadcast Also available through the phone or on the internet

17. AWOS Automated Weather Observing System ▪ AWOSs cost about $94,000 and are much less expensive than ASOSs ▪ Who owns them ▸ Federal AWOSs are maintained by the FAA ▸ Most AWOSs are owned and maintained by states, airports, or other local interest ▪ There are three main types of AWOSs ▸ AWOS I - temp, dew point, pressure, wind, density altitude ▸ AWOS II - adds visibility ▸ AWOS III - adds cloud information – AWOS IIIp - adds precipitation type sensor

18. Decoding METARs METAR KTPA 101955Z 33015G22KT 1/2SM FG VV002 19/19 A2955 RMK A02 PK WND 32035/1915 TWR VIS 3/4 SLP028 P0004 T01920188 Remarks Automated precipitation reporting Peak wind northwest at 35kts at 1915Z Tower visibility 3/4 mile Sea level pressure 1002.8 MB 00.04" rain in last hour Temp = 19.2 C Dew = 18.8 C

19. Weather Balloons ▪ Launched at the same time across the world (11Z & 23Z) ▪ Rises 1000 feet per minute ▪ Reaches 90,000 ft in 1.5 hours ▪ Balloon expands to 35 feet before exploding ▪ Measures: ▸ Temperature ▸ Dew Point ▸ Wind direction and speed ▸ Pressure

21. Radiosonde Data Station Map and Data Plot

22. WSR-88D Radar 154 WSR-88D sites About a 250nm range Detects precip and velocity data An additional 45 TDWR Sites – Higher resolution data

23. Composite vs. Base Reflectivity

25. Forecasting 101 – Model Data Ballooning = mesoscale models – Or models that take into account local effects WRF – Run at NWS offices – Small scale model – Data hourly – Check with your local office for availability on the web

26. Model Data Continued… RUC – Designed for aviation community – Rapid update (hourly) – 1hr time steps MOS Guidance – Model Output Statistics Takes model data and interprets it for specific points (airports, METAR sites, etc) Also uses statistics…or climatology for that site – Run every six hours

27. MOS Bulletins

28. Model Data Continued… LAMP (Localized Aviation MOS Guidance) – Will probably be the most helpful to balloonists!! – Updates GFS MOS on an hourly basis – Forecasts elements every hour

29. LAMP Guidance

31. Forecasting 101 - Forecasts The NWS does the work for you! – Text Forecasts – Discussions – Aviation Forecasts – Graphical Forecasts www.weather.gov

32. NWS Products Forecast discussions – Out to 7 days – Include aviation section 7-day point and click forecast Graphical forecasts – Hourly weather graphs based on graphics

34. Terminal Aerodrome Forecasts (TAFs) Most used aviation forecast Valid for 24-30hrs Issued every 6hrs – Amended/updated as needed “Magic” threshold for winds = 12kts – Too high for balloonists?

35. Decoding TAF Forecasts Slightly different time format now TEMPO groups = <50% of the time Difference between CB, VCTS and TS?

36. How can you access all of this data?

37. RUC Soundings/Winds http://rucsoundings.noaa.gov/gifs/

38. Text Bulletins LAMP guidance (listed by state/site): http://www.nws.noaa.gov/mdl/gfslamp/bullform.html MOS Bulletins: http://www.weather.gov/mdl/synop/products.php

39. Decoding Observations http://www.ncdc.noaa.gov/oa/climate/co nversion/swometardecoder.html

40. Dialing ASOS Sites http://www.faa.gov/air_traffic/weather/asos/

41. Other useful websites Aviation Weather Center: http://www.aviationweather.gov http://adds.aviationweather.gov/

42. Other Useful Websites Check with your local NWS office – Aviation Section on website – Aviation Focal Point Can give talks, provide more information, etc. http://www.weather.gov

43. Radar Data http://www.weather.gov/radar_tab.php Can toggle: – Warnings – Topography – Cities – Highways

44. Questions?