1. Outback Air Race 2012 James Lannan Bureau of Meteorology

2. Perth to Darwin…via the rest of Australia…  Perth to Ceduna: –Mid latitude weather.  Ceduna  Charleville  Darwin –Mid latitude weather initially –Tropical weather (~ North of Longreach, QLD; ~23.5ºS)  Darwin  Perth –Tropical weather initially. –Mid latitude weather to finish (~South of Newman; ~23.5 ºS. This boundary will be discussed later). Mid Latitude Weather: Covered mostly in the “Flying the Southwest”“Flying the Southwest” Tropical Weather: Covered by the “Flying the Tropics”“Flying the Tropics”

3. What should you expect?  Mid Latitude Weather: Southern Australia (~South of 23.5ºS; ~ South of Alice Springs) –Cold fronts/Low pressure systems. –Turbulence. –Fogs. –Thunderstorms. –Fires (mostly controlled burns)  The Tropics: Northern Australia (~ North of Alice Springs) –Will still be dry season. Well timed! –Bushfires/Burning off programs. –Dust. –Possible turbulence. –Fogs and Thunderstorms possible but unlikely.

5. Winds: August Mean – 300ft

6. Winds: August Mean – A050

7. Winds: August Mean – FL100

8. 8 Satellite Observations  Satellites provide 24 hour information on development and movement of weather systems  Infra-Red Images – detect temperatures Excellent for viewing broadscale weather patterns in motion

9. 9 Weather Radar Observations  Images provide warnings of major weather events such as thunderstorms, tropical cyclones and areas of heavy rainfall

10. Radar Locations

11. 11 Combined Satellite and Radar

12. Cold Fronts – Southern Aus  Mainly affect southern half of Australia, however can trigger weather further north.  Hazards: –Thunderstorms and showers, hail possible –Low cloud and low visibility in rain. –Strong winds –Fog the night or two after a frontal passage.

13. Northwest cloud bands: - Entire route.  Warm moist tropical air moving southeast over continent.  Large systems, often associated with a cold front.  Large vertical and horizontal extent of cloud.  Hazards: –Low cloud. –Embedded thunderstorms –Fogs. –Rain

14. Turbulence/Nocturnal low level jets.  Low-level jets – Wind shear –Inland tropical areas during winter. Eg: Mount Isa, Tennant Creek, Halls Creek. –Occur mainly below 3000ft above ground level. –Wind speeds typically ~25 knots, 50kt possible.  Turbulence –Thermals –Rough guide: if surface temperatures >30º –Any hilly/mountainous areas can contain turbulence, ie: Perth escarpment, McDonnell Ranges. –Cold Fronts can contain strong wind shear/turbulence.

15. Fogs/low cloud  Mainly form in coastal areas, however if a northwest cloudband or cold front has passed through, central areas susceptible as well.  Sea fogs common around Gulf of Carpentaria coast.  Clear by mid-morning.

16. Dust Storms  Usually observed in inland areas during the dry season.  Generally in the order of 6-8km width.  Visibility may be <300m.  Often linked to a cold front passing over southern Australia.  Dust devils also possible, visible vortices with small diameter (<100m). May extend up a few thousand feet. Take-offf/Landing hazard.

17. Smoke  Dry season = Burning off season.  Controlled burns.  Low visibility in thick smoke.  Sentinel – Geoscience Australia.

18. Morning Glory cloud  Quite rare, but would be incredible to see!  Often form in the late dry, commonly near Burketown.  Prevailing SE’ly wind mixes with sea breeze off Gulf of Carpentaria.  Wind squall/wind shear often present.

19. 19 Aviation Forecasts & Warnings: Aerodrome Forecast (TAF)  Forecast weather is expressed using the following abbreviations: Weather Descriptor MIshallowDRdriftingFZfreezing BCpatchesBLblowingTSthunderstorm PRpartial Weather Phenomena DZdrizzleSSsandstormPOdust devil RArainDSduststormSQsquall GRhailGSsmall hail/snow pelletsFCfunnel cloud SNsnowFGfogVAvolcanic ash SGsnow grainsBRmistICice crystals DUdustFUsmokePLice pellets SAsandHZhaze

20. 20 Aviation Forecasts & Warnings: SIGMET  SIGMETs are issued to advise of the occurrence or expected occurrence of the following phenomena: CodeDescription OBSC TSObscured thunderstorms EMBD TSEmbedded thunderstorms FRQ TSFrequent thunderstorms SQL TSSquall line thunderstorms OBSC TSGRObscured thunderstorms with hail EMBD TSGREmbedded thunderstorms with hail FRQ TSGRFrequent thunderstorms with hail SQL TSGRSquall line thunderstorms with hail TCTropical cyclone CodeDescription OBSC TSObscured thunderstorms SEV TURBSevere turbulence SEV ICESevere icing SEV ICE FZRASevere icing due to freezing rain SEV MTWSevere mountain wave HVY DSHeavy duststorm HVY SSHeavy sandstorm VAVolcanic ash

21. Please ensure you…  Obtain the latest aviation observations, forecasts, warnings and charts from the briefing system  Telephone the Bureau for a more elaborative briefing, when appropriate  Pay attention to media weather presentations and reports.  A useful site for looking up ongoing fires burning around the country: http://sentinel.ga.gov.au/acres/sentinel/

22. 22 For More Information … www.bom.gov.au 1. Weather & Climate information 2. Capital City Forecasts 3. Images & Charts 4. Aviation Weather Services

23. 23 Aviation Forecasts & Warnings  Include detailed information on: –Temperature & Wind –Cloud type, height & depth –Weather (Thunderstorms, rain/showers, snow, fog/mist etc) –Visibility –Turbulence & Icing –Significant changes in the current pattern  Special Warnings are issued for: –Severe turbulence & icing –Severe low-level wind shear –Frequent, embedded, or an unbroken line of thunderstorms –Volcanic Ash –Cyclones  Airlines & ATC are notified of deteriorations immediately!