1. Clearing the Air on G-AIRMET Ryan Solomon and Gregory Harris Aviation Weather Center

2. Introduction In March 2010 the G-AIRMET became a “Primary” Operational Weather Product The FAA designation allows pilots and weather briefers to use G-AIRMETs as a primary decision making tool for anticipating and avoiding weather hazardous to safe flight operations The Graphical Airman’s Meteorological Advisory (G-AIRMET) has been operationally produced as a “supplementary” product since October 2008

3. Topics How it began Evolution Safety Definition Depiction Difference from text AIRMET Available formats Where to get it

4. How it began G-AIRMET is the collective response from the Federal Aviation Administration (FAA) and the National Weather Service to answer that call A “call” began to be heard from the users of the National Airspace System for higher resolution weather hazard information Text-based forecasts made logical sense 20 or more years ago, when teletype and facsimile were the primary methods of transmitting weather to pilots

5. Evolution First software prototype released to forecasters in 2003 Idea to change to a graphical forecast process was born in 2000 Operational production of the G-AIRMET as a supplementary product began in 2008 G-AIRMET becomes a primary product in 2010

6. Safety G-AIRMET thoroughly scrutinized by a FAA Safety Risk Management Assessment Team (including controllers, dispatchers, pilots, and meteorologists) Team identified potential risks and implemented mitigation measures – –Removal of the AIRMET VOR Plot on websites (had potential to confuse users)

7. Definition The Graphical AIRMET is: A graphical forecast of en-route weather hazards A series of snapshots at 3 hour intervals valid for up to 12 hours  00 hour represents the initial conditions  the subsequent 3-hourly graphics depict the area affected by the particular hazard at that valid time Routinely issued every 6 hours Updated as needed

8. Depiction G-AIRMETs depict the following en-route aviation weather hazards: Instrument flight rule conditions (IFR) Mountain Obscuration Turbulence Low Level Wind Shear (LLWS) Strong Sustained Surface Winds Icing Freezing Level

9. G-AIRMET Sierra Weather HazardG-AIRMET Criteria/Depiction Surface Visibility≤3 miles (IFR) Cause of Surface Visibility restriction Precipitation (PCPN), Mist (BR), Fog (FG), Haze (HZ), Smoke (FU), Blowing Snow (BLSN) Low CeilingsCeiling ≤1000 feet (IFR) Mountain ObscurationArea Cause of Mountain Obscuration Clouds (CLDS), Precipitation (PCPN), Mist (BR), Fog (FG), Haze (HZ), Smoke (FU)

10. G-AIRMET Tango Weather HazardG-AIRMET Criteria/Depiction TurbulenceModerate, Surface to 40,000 feet Sustained Surface Winds ≥ 30 knots Low Level Wind Shear Wind shear (+/-10 knots) below 2000 feet AGL

11. G-AIRMET Zulu Weather HazardG-AIRMET Criteria/Depiction Icing (non-convective) Moderate Airframe Icing Surface to 45,000 feet Freezing Level Location of the freezing level at the Surface, 4,000, 8,000, 12,000, and 16,000 feet Multiple Freezing LevelsArea and vertical range

12. Differences from Text AIRMET F00 Aerial Coverage Depth F03 F06 G-AIRMET SnapshotsArea of Text AIRMET F00F03F06=++6HR Smear

13. This example shows a 00hr through 06hr G-AIRMET icing forecast for the Western U.S. - The G-AIRMET detail provides greater aerial and depth detail vs. the final Legacy AIRMET - The western edge of the G-AIRMET depicts a shallower icing layer depth, this detail is not correlated in the Text. WAUS45 KKCI 081445 SLCZ WA 081445 AIRMET ZULU UPDT 3 FOR ICE AND FRZLVL VALID UNTIL 082100 AIRMET ICE...ID MT UT WA OR FROM 80ESE YDC TO 60NW GGW TO 40WSW LWT TO 20S MLD TO 20ESE REO TO 80ESE YDC MOD ICE BLW FL180. Differences from Text AIRMET

14. G-AIRMET Formats BUFR “Binary Universal Form for the Representation of Meteorological Data”  Allows users to customize displays GIF “Graphics Interchangeable Format (GIF)” images JAVA display  Allows looping, overlaying, and zooming Coming Soon... GIS based products

15. G-AIRMET on the Web AviationWeather.gov   Advisories   SIGMET/AIRMET Java Tool US (CONUS) AWC Oceanic   Graphical AIRMET

16. Graphical AIRMET Interactive G-AIRMET page allows the user to select: - Individual or multiple hazards - Display the time of interest - Loop the entire set - View Static G-AIRMET Images - View (CONUS) Text AIRMETs

17. Graphical AIRMET

18. Text AIRMETs Previously we clicked the Text AIRMET link. To view the Text AIRMETs: 1.Click on the type of hazard. 2.Click on the area desired. 3.Click on the Retrieve button. 4. The Text AIRMET will be retrieved in that same window. 5. Click link on top of the page to select another Text AIRMET

19. AWC US(CONUS) Page Provides “one-stop” shop for: G-AIRMET (Interactive and Static Displays, AIR/SIGMET Java Tool & Oceanic SIGMET Text AIRMETs / SIGMETs Displays Currently Active SIGMETs with individual links to each possible SIGMET category http://aviationweather.gov/adds/

20. Static G-AIRMET

21. G-AIRMET Summary   No change to text AIRMET   Improves temporal and spatial forecast resolution   Provided in three formats – BUFR, Java, GIF   Allows pilots to maintain high safety margins while flying more efficient routes