~ Aviation Management ~

Ch. 7 Notes [Private Pilot]

- When the dew is on the grass, rain will never come to pass. When grass is dry at morning light, look for rain before the night.

- The farther the sight, the nearer the rain. (True near large bodies of water; mixing of the atmosphere due to instability coupled with the lack of evaporation contributes to relatively clear air.)

- Telephone wires hum and whine when a weather change is due. (Cold, dry air tends to tighten the wires, making them hum, occurring when cold air and associated storms move in.)

- Rainbow in the morning, sailor take warning; Rainbow toward night, sailors delight. (Storms in North American generally move from west to east, a morning rainbow would indicate that the storm is still to the west. A rainbow seen in the evening would have to be to the east, meaning the storm has passed.

- Winds are reported in reference to true north.

- Wind gusts are reported using a G followed by the highest gust.

- Prevailing visibility is reported in statute miles, as indicated by the abbreviation SM.

- A ceiling is the lowest broken or overcast layer, or vertical visibility into an obstruction.

- In controlled airspace, VFR conditions exist with a visibility of at least 3 statute miles and a ceiling of 1,000 ft. or more.

- Cloud heights or the vertical visibility into an obscuration are reported with three digits in hundreds of feet.

- The beginning of the remarks section is indicated by the code RMK. The remarks section reports weather considered significant to aircraft operations.

- PIREPs use a standard format, altitudes are given in hundreds of feet above mean sea level (MSL).

- TAFs usually are valid for a 24-hour period and are scheduled four times a day. TAF codes are similar to those used in METARs.

- Cumulonimbus (CB) is the only type of cloud included in the TAF.

- In a winds and temperature aloft forecast, winds are given in true direction and speed is shown in knots.

- Wind direction and speed information on an FD is shown by a four-digit code. The first two digits are the wind direction in tens of degrees. Wind speed is shown by the second two digits. The last two digits indicate the temperature in degrees Celsius. All temperatures above 24,000 ft. are negative.

- To decode a forecast of winds between 100 and 199 knots, subtract 50 from the two-digit direction code and multiply by 10. Then, add 100 to the two-digit wind speed code. If the code 9900 is used, it means the winds are light and variable.

- AIRMETs warn of weather conditions which are particularly hazardous to small, single-engine aircraft.

- SIGMETs warn of weather hazards, such as severe icing, which concern all aircraft.

- Convective SIGMETs warn of weather hazards including tornadoes, embedded thunderstorms, and hail 3/4 inch or greater in diameter.

- A stationary front is depicted with rounded warm front symbols on one side and triangular cold front symbols on the opposite side.

- A station circle on a weather depiction chart shows the visibility, cloud height or ceiling, and weather and/or obstructions to vision.

- For flight planning, the weather depiction chart is most useful for determining general weather conditions and quickly locating areas of adverse weather.

- Radar summary charts depict the location of precipitation along with the type, intensity, and cell movement.

- Individual thunderstorm cells as well as lines of thunderstorms are depicted on radar summary charts. Since radar only reflects precipitation, it does not detect cloud formations.

- In addition to helping you avoid areas of significant turbulence, the information contained on the low-level significant weather prog chart helps you avoid areas where temperatures are conducive to aircraft icing.

- Symbols used to define areas of IFR, MVFR, VFR, and moderate or greater turbulence, as well as the forecast altitude of the freezing level, are depicted in the legend between the two upper panels of the low-level significant weather prog chart.

- On the low-level significant weather prof chart, solid lines enclose areas of precipitation. Shading is used to describe the precipitation conditions and coverage. Continuos precipitation covering more than half of the area is shaded. Intermittent precipitation covering half or less of the area is unshaded. 

- Turbulence is depicted on the low-level significant weather prog chart with a peaked symbol. Underneath the symbol, figures indicate the top and base of the turbulence.

- When you contact a weather briefer, identify yourself as a pilot flying VFR and provide the briefer with your aircraft number or your name, type of aircraft, intended route, destination, and other relevant background data for the flight.

- The standard briefing provides the most complete information concerning weather for your flight. When you request a standard briefing, the weather briefer assumes you have not received any preliminary information.

- ; - Adverse Conditions; includes the type of information that might influence you to alter your proposed route or cancel the flight altogether. Examples include such things as hazardous weather or airport closures.

- ; - VFR Flight Not Recommended; if the flight service briefer indicates that VFR flight is not recommended, it means that, in the briefer's judgement, it is doubtful that you can complete the flight under VFR. Although the final decision to conduct the flight rests with you, this advisory should be taken seriously.

- ; - Synopsis; the briefer will provide you with a broad overview of the major weather systems or airmasses that affect the proposed flight.

- ; - Current Conditions; this information is a rundown of existing conditions, including pertinent hourly, pilot, and radar weather reports. Unless you request otherwise, this item is omitted if your proposed departure time is more than two hours in the future.

- ; - Enroute Forecast; the briefer will summarize the forecast conditions along your proposed route in a logical order from departure through descent for landing.

- ; - Destination Forecast; the briefer will provide the forecast for your destination at your estimated time of arrival (ETA). In addition, any significant changes predicted for an hour before or after your ETA will be included.

- ; - Winds and Temperature Aloft; you will be given a summary of forecast winds for your route. If necessary, the briefer will interpolate wind direction and speed between levels and stations for your planned cruising altitude. Temperature information will be provided on request.

- ; - Notices to Airmen; The briefer will supply NOTAM information pertinent to your proposed route of flight. However, information which has already been published in the Notices to Airmen publication will only be provided on request.

- ; - ATC Delays; you will be advised of any known air traffic control delays that might affect your proposed flight.

- ; - Request for Pireps; the briefer may ask you to file a PIREP if the current conditions would benefit from addition inflight weather reports.

- ; - EFAS; you will be notified of the availability and appropriate frequency for Flight Watch for enroute weather updates.

- ; - Other Information; upon request, the briefer will provide you with other information such as MOA and MTR activity within 100 n.m. of the flight plan area, ATC services and rules, as well as customs and immigration procedures.

- Request an abbreviated briefing to update weather information from mass dissemination sources, e.g. telephone information briefing service, or an earlier briefing.

- You should request an outlook briefing when your proposed departure is six or more hours in the future.

- EFAS favilities provide actual weather information, including any thunderstorm activity which might affect your route.

- The frequency for EFAS (Flight Watch) below 18,000 ft. MSL is 122.0 MHz.

- TWEB recordings are broadcast over selected NDBs and/or VORs. The recorded messages typically provide a variety of information including specific route forecasts and winds aloft information.