Aviation Weather
how do you obtain a Weather Briefing
call 1800-wx-brief
Abbreviated weather briefing
is a shortened version of the standard briefing. It should be requested when a departure has been delayed or when weather information is needed to update the previous briefing.
PIREP
provide valuable information regarding the conditions as they actually exist in the air, which cannot be gathered from any other source. PIREPS Include: 3-letter station identifier Routine PIREP, UUA-Urgent PIREP. Location Time Altitude/Flight level Type Aircraft Sky cover/Cloud layers Weather Air temperature in Celsius (C) Wind Turbulence Encoding Pilot Weather Reports (PIREPS) Icing Remark
Radar Summary Chart
- is a graphically depicted collection of radar weather reports It displays areas of precipitation, as well as information regarding the characteristics of the precipitation -The chart is published hourly at 35 minutes past the hour.
Surface Analysis Chart
-depicts an analysis of the current surface weather. -This chart is a computer prepared report that is transmitted every 3 hours and covers the contiguous 48 states and adjacent areas. -A surface analysis chart shows the areas of high and low pressure, fronts, temperatures, dew points, wind directions and speeds, local weather, and visual obstructions. Type of observation Sky cover Clouds Wind speed Total sky cover High cloud type Wind direction Middle cloud type Temperature Sea level pressure Present weather Pressure change in past 3 hours Sea level pressure Pressure change/tendency Precipitation. Dew point—given in degrees Fahrenheit. Present weather Temperature—given in degrees Fahrenheit. Wind—true direction of wind is given by the wind pointer line, indicating the direction from which the wind is coming. A short barb is equal to 5 knots of wind, a long barb is equal to 10 knots of wind, and a pennant is equal to 50 knots.
Area Forecasts (FA)
-gives a picture of clouds, general weather conditions, and visual meteorological conditions (VMC) expected over a large area encompassing several states. -issued three times a day -are valid for 18 hours. 6 areas: San Francisco, Salt lake City, Miami, Dallas Fort Worth, Chicago, Boston(OH-ou)
SIGMETS
-inflight advisories concerning non- convective weather that is potentially hazardous to all aircraft. -servere -They report weather forecasts that include severe icing not associated with thunderstorms, severe or extreme turbulence or clear air turbulence,not associated with thunderstorms, dust storms or sandstorms that lower surface or inflight visibilities to below three miles, and volcanic ash. -SIGMETs are unscheduled forecasts that are valid for 4 hours, but if the SIGMET relates to hurricanes, it is valid for 6 hours. -A SIGMET is issued under an alphabetic identifier, from November through Yankee, excluding Sierra and Tango.
TAF- Terminal Aerodrome Forecasts
-is a report established for the five statute mile radius around an airport. TAF reports are usually given for larger airports. -Each TAF is valid for a 30-hour time period -updated four times a day at 0000Z, 0600Z, 1200Z, and 1800Z. TAFS include: 1. Type of report 2. ICAO station identifier 3. Date and time of origin 4. Valid period date and time 5. Forecast wind 6. Forecast visibility 7. Forecast significant weather 8. Forecast sky condition 9. Forecast change group 10. Probability forecast
METAR
-is an observation of current surface weather reported in a standard international format. -issued hourly unless significant weather changes have occurred. -includes the following information 1. Type of report 2. Station identifier 3. Date and time of report 4. Modifier 5. Wind 6. Visibility 7. Weather 8. Sky condition 9. Temperature and dew point 10. Altimeter setting 11. Zulu time
AIRMET
-issued every 6 hours with intermediate updates issued as needed for a particular area forecast region. -The info in an AIRMET interest to all aircraft, but the weather section concerns phenomena considered potentially hazardous to LIGHT aircraft and aircraft with limited operational capabilities. -moderate -Sierra- IFR and mountain obscuration -Tango- turbulence, strong surface winds, and low-level wind shear -Zulu- icing and freezing levels. -includes forecast of moderate icing, moderate turbulence, sustained surface winds of 30 knots or greater, widespread areas of ceilings less than 1,000 feet and/or visibilities less than three miles, and extensive mountain obscurement.
Winds and Temperature Aloft Forecast (FD)
-provide wind and temperature forecasts for specific locations in the contiguous United States -made twice a day based on the radiosonde upper air observations taken at 0000Z and 1200Z. -Through 12,000 feet are true altitudes and above 18,000 feet are pressure altitudes. -Wind direction is always in reference to true north and wind speed is given in knots. -The temperature is given in degrees Celsius.
Inflight Weather Advisories
-provided to en route aircraft, are forecasts that detail potentially hazardous weather. These advisories are also available to pilots prior to departure for flight planning purposes. -issued in the form of either an AIRMET, SIGMET, or convective SIGMET.
Outlook weather briefing
An outlook briefing should be requested when a planned departure is 6 hours or more away.
Standard weather briefing
Most detailed weather briefing consist of: 1.Adverse conditions 2. VFR flight not recommended 3. Synopsis 4. Current conditions 5. En route forecast for the proposed route of flight. 6. Destination forecast 7. Winds and temperatures aloft 8. Notices to Airmen (NOT AM) 9. ATC delays 10. Other information
Significant Weather Prognostic Charts
are available for low- level significant weather from the surface to FL 240 (24,000 feet), and high-level significant weather from FL 250 to FL 600 (25,000 to 60,000 feet). -The low-level chart comes in two forms: the 12 and 24 hour forecast chart, and the 36 and 48 hour surface forecast chart. Charts are issued four times a day at 0000Z, 0600Z, 1200Z, and 1800Z. The valid time for the chart is printed on the lower left corner of each panel.