Aviation Wx

Water Evaporation and Sublimation

  • Annual Evaporation: 20 to 30 inches from oceans and sublimation.

  • Mid-Latitudes: 40 to 60 inches/year.

  • Equatorial Regions: 80 to 110 inches/year (8.33-10 feet).

  • Importance: Essential in weather forecasting for pilots and meteorologists.

Introduction to METARs and TAFs

  • METARs: Hourly reports of weather conditions crucial for pilots.

  • TAFs: Provide important weather forecasts for airports to assist in flight planning.

Differences Among METARs, TAFs, and ATIS

  • ATIS: Automated weather broadcasts for pre-landing checks.

  • Data Impact: Affects runway selection, flap settings, and speeds.

METAR Formats

  • Standard Measurements: Uses inches of mercury; weather data denoted as WX.

  • ICAO Designator: Begins with airport identifier (e.g., KPDX).

  • Station Types: AO1 (no precipitation identification) and AO2 (can identify precipitation type).

Interpreting METARs

  • Sky Conditions: Descriptions of cloud coverage; broken and overcast are ceilings measured AGL.

  • Temperature & Altimeter: Reported in Celsius and inches, respectively.

Practical Example

  • METAR Example: Phoenix report shows wind, visibility, temperature, and altimeter settings.

  • TAF Example: Issued four times daily, useful for flight planning.

Conclusion

  • Understanding METARs and TAFs is vital for flight safety. Awareness of reporting standards is important for staying current.

  • Next Class: Write information on provided cards.