The ICAO Weather Information Exchange Model (IWXXM) package, including METAR, SPECI, TAF, and SIGMET reports as defined in ICAO Annex 3, 17th edition.  These four reports are essential operational meteorology products used to enable safe and efficient air travel worldwide.<br /></p><p><br /></p><p>The report types in this package include:<br /></p><p><b><br /></p><p></b><b>== </b>METAR <b>==</b><br /></p><p>Routine observation of meteorological conditions made at an aerodrome throughout the day.  METARs may also include short-term forecasts of meteorological conditions<br /></p><p><b><br /></p><p></b>== SPECI ==<br /></p><p>Special (i.e., non-routine) observation of meteorological conditions made at an aerodrome as needed.  SPECIs may also include short-term forecasts of meteorological conditions<br /></p><p><b><br /></p><p></b>== TAF ==<br /></p><p>Routine aerodrome forecasts of meteorological conditions<br /></p><p><b><br /></p><p></b>== SIGMET ==<br /></p><p>Meteorological advisory concerning the occurrence and/or expected occurrence of weather phenomena which may affect the safety of aircraft operations, such as severe thunderstorms or turbulence<br /></p><p><br /></p><p>This package builds upon the ISO 19100 family (ISO TC211) and WMO standard meteorological modeling constructs. Additionally, the constructs in this application schema refer to a number of aviation constructs such as FIR, Aerodrome, and Runway from the Simple Aviation Features package.  The full relationship of this package with external dependencies are shown in the 'Package Dependencies' diagram.<br /></p><p><br /></p><p>While only four of the reports from Annex 3 are currently represented, this may be expanded in a future version.<br /></p>