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Graphical Area Forecast User Guide a Guide for the Transition from Arfors to GAF

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Graphical Area Forecast User Guide a Guide for the Transition from Arfors to GAF Graphical Area Forecast User Guide A guide for the transition from ARFORs to GAF October 2017 | Version 1.2 Graphical Area Forecast User Guide Document Control Revision history VERSION DATE DESCRIPTION AUTHOR 1 15 September 2017 Final version Elizabeth Heba Update to provide clarification on AIRMETs 1.1 13 October 2017 Elizabeth Heba and SIGMETs Update to GAF samples and worked example 1.2 20 October 2017 Additional text in Area Briefing (NAIPS) Ashwin Naidu Section Update to abbreviation examples Approval for release DATE NAME Position Signature National Manager Aviation 20 October 2017 Gordon Jackson Meteorological Services Version number Date of issue th Version 1.2 20 October 2017 © Commonwealth of Australia 2017 This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced without prior written permission from the Bureau of Meteorology. Requests and inquiries concerning reproduction and rights should be addressed to the Production Manager, Communication Section, Bureau of Meteorology, GPO Box 1289, Melbourne 3001. Information regarding requests for reproduction of material from the Bureau website can be found at www.bom.gov.au/other/copyright.shtml ii Graphical Area Forecast User Guide Table of Contents 1 Purpose .......................................................................................................................................... 1 2 Introduction .................................................................................................................................... 2 3 Key Changes .................................................................................................................................. 5 3.1 Changes to Domain .................................................................................................................................. 5 3.1.1 Area Forecast Boundaries ......................................................................................................................... 5 3.1.2 Area QNH Boundaries ............................................................................................................................... 6 3.2 Changes to Low Level Area Forecast Content ...................................................................................... 7 3.2.1 Validity Periods and Issue Times ............................................................................................................... 7 3.2.2 Overview .................................................................................................................................................... 8 3.2.3 Wind and Temperature Information............................................................................................................ 8 3.2.4 Weather and Visibility ................................................................................................................................. 8 3.2.5 Cloud, Icing and Turbulence ...................................................................................................................... 8 3.2.6 Freezing Level ........................................................................................................................................... 9 3.2.7 Critical Locations ........................................................................................................................................ 9 3.2.8 Weather Features ...................................................................................................................................... 9 3.2.9 Amendments and Corrections .................................................................................................................... 9 3.2.10 Product Output Format ............................................................................................................................... 9 3.2.11 Area Briefing (NAIPS) .............................................................................................................................. 10 4 Graphical Area Forecast Layout ................................................................................................ 11 4.1 Product Layout ....................................................................................................................................... 11 4.2 Header ..................................................................................................................................................... 11 4.3 Image ....................................................................................................................................................... 11 4.4 Table ........................................................................................................................................................ 12 4.5 Legend ..................................................................................................................................................... 12 4.6 Remarks .................................................................................................................................................. 12 5 Graphical Area Forecast Content .............................................................................................. 13 5.1 Times of Issuance and Periods of Validity ........................................................................................... 13 5.2 Image ....................................................................................................................................................... 13 5.3 Meteorological Information Table ......................................................................................................... 14 5.3.1 Column 1: Area ........................................................................................................................................ 15 5.3.2 Column 2: Surface Visibility and Weather ................................................................................................ 15 5.3.3 Column 3: Cloud, Icing and Turbulence ................................................................................................... 16 5.3.4 Column 4: Freezing Level ........................................................................................................................ 18 5.3.5 Use of Sub Areas ..................................................................................................................................... 19 5.4 Critical Locations ................................................................................................................................... 21 5.4.1 Weather Information................................................................................................................................. 21 5.4.2 Visibility Information ................................................................................................................................. 21 5.4.3 Cloud information ..................................................................................................................................... 22 iii Graphical Area Forecast User Guide 5.4.4 Additional Information .............................................................................................................................. 22 5.5 GAF Worked Example ............................................................................................................................ 22 6 Changes to GAF and Corrected GAF ........................................................................................ 26 6.1 Corrections ............................................................................................................................................. 26 6.2 Corrected GAF Worked Example .......................................................................................................... 27 7 AIRMET ......................................................................................................................................... 29 7.1 Issuance .................................................................................................................................................. 29 7.2 Extension ................................................................................................................................................ 30 7.3 Cancellation ............................................................................................................................................ 30 8 Grid Point Wind and Temperature Forecasts ........................................................................... 32 8.1 Introduction ............................................................................................................................................ 32 8.2 Layout ...................................................................................................................................................... 32 8.3 Domain .................................................................................................................................................... 33 8.4 Product Format ....................................................................................................................................... 34 8.5 Issue Times and Validity Periods .......................................................................................................... 34 8.6 Deconstructing Low-level GPWT Forecast Charts .............................................................................
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