Weather Flashcards
What causes Weather?
- The Sun’s uneven heating of Earth
Who issues all weather regarding aviation?
- National Weather Service
What is a Meteorological Aerodome Report (METAR)?
- They report the current weather within 5NM of an airport
- They are updated every hour and are good for an hour
What is a Terminal Area Forecast (TAF)?
- They forecast the weather within 5NM of an airport
- They are updated every 6hrs and are good for 24-30hrs
What is an Airmen’s Meteorological Information (AIRMET)?
- They advise of weather that maybe hazardous to single engine, other light aircraft, and VFR pilots. However, operators of large aircraft may also be concerned with these reports
- They are updated every 6hrs and are good for 6hrs
What are the types of AIRMETs?
- T: Turbulence
- Z: Icing
- S: Mountain Obscurations
What is a Significant Meteorological Information (SIGMET)?
- They are a severe weather advisory that concern the safety of all aircraft
- They are unscheduled and most of them are valid for 4hrs
What are the types of SIGMETs?
- Icing
- Turbulence
- Duststorms/Sandstorms
- Volcanic Ash
- Hurricane - valid for 6hrs
- Convective - valid for 2hrs
What could be considered a Convective Sigmet?
- Thunderstorms
- Hail
- Tornadoes
What is a Center Weather Advisory (CWA)?
- They are an unscheduled weather advisory for conditions approaching or meeting WA, WS, or WST criteria
- They are valid for 2hrs and conditions are expected to begin within 2hrs of issuance
What are Notice To Air Mission (NOTAM)?
- They are a notice containing information essential to flight operations but not known far enough in advance to be publicized
What are Pilot Weather Reports (PIREPs)?
- They are reports of current weather encountered by pilots
- They can be submitted to a FSS, NWS website, or to ATC (say “with pilot report”)
What is a High Pressure system?
- An area where the atmospheric pressure is higher than its surroundings
What are the characteristics of a High Pressure system?
- They move down and outward in a clockwise direction
- They generally bring fair weather
What is a Low Pressure System?
- An area where the atmospheric pressure is lower than its surroundings
What are the characteristics of a Low Pressure system?
- They move up and inward in a counter-clockwise direction
- They usually bring bad weather
What is a Trough?
- It is an extended area of low pressure
How can you indentify a Trough on a Prog Chart?
- They are represented by an orange line
What are Isobars?
- They are light gray lines on a prog chart that connect areas with the same pressure (measured in millibars)
What happens when you fly across Isobars?
- You may encounter changes in wind speed and direction
What is an Air Mass?
- A large body of air with generally uniform temperature and humidity
- They are created by source regions
What is a Front?
- The boundary between air masses
- They bring a change in weather
What happens when you fly across a Front?
- You will notice a change in temperature, pressure, wind, and other factors
What is a Sea Breeze?
- It is not a front but it also generates weather
What is a Cold Front?
- When a cold air mass wedges underneath a warm air mass, forcing the warm air to rise. The cold air advances, replacing the warm air at the surface. Rain and even thunderstorms can form as the moisture in the warm air mass rises, cools, and condenses
What are the characteristics of a Cold Front?
- They typically travel between 10-30kts
- They usually bring light to heavy rain and thunderstorms, depending on the steepness of the front’s slope
- As the front passes, cool and fair weather is expected
What are Squall Lines?
- It is a line of thunderstorms, often forming along or ahead of a cold front