Weather Flashcards
What are acceptable weather sources to use on the ground?
1-800 weather brief
Aviationweather.gov
Foreflight
FSS
What are acceptable weather services to use while enroute?
Metars
FSS
Atc if able
Atis/asos/awos
NEXRAD
What are the types of weather briefings you can get from 1-800 wxbrief?
Outlook
Standard
Abbreviated
When would you get an outlook weather briefing?
Outlook weather briefings are good if you plan on flying in 6 or more hours.
What is a standard briefing?
A briefing you can get within 6 hours of the flight time. Has all airport, and enroute weather information.
What is an abbreviated briefing?
A briefing updating one you have already gotten.
What is a convective sigmet and how long is it valid for?
Issued for:
•Severe thunderstorms
-sfc winds greater or equal to 50knots
- hail over a 3/4inch diameter
-tornados
•heavy precip covering 40% of 3000 sq miles
•embedded thunderstorms
•severe turbulence
•severe icing
•low level wind shear
Valid for 2 hours
What is a SIGMET and how long is it valid?
•Severe icing
•Severe or extreme turbulence
•dust or sandstorms either visibility less than 3 miles
•volcanic ash
(All not related to thunderstorms)
Valid for 4 hours
What is a AIRMET and there types?
Airmets are usually issued for less severe weather(small GA aircraft’s)
•AIRMET Sierra
•AIRMET Tango
•AIRMET Zulu
Valid for 6 hours
What is a AIRMET Sierra?
-IFR conditions or mountain obstruction
What is a AIRMET Tango
(T in Tango for Turbulence)
-Moderate Turbulence
-Surface winds greater or equal to 30 knots
-Low level wind shear (LLWS)
What is a AIRMET Zulu?
-Moderate icing
-Freezing levels
What is Atmospheric Stability?
The ability to resist vertical movement.
What determines if an atmosphere is stable or unstable?
The lapse rate
-2c for every 1000 feet
If it is greater then this it is unstable because it favors vertical movement.
What are the three main things effecting wind?
-unequal heating of earths surface
-Coriolis effect
-surface friction
How does unequal heating of the earths surface affect wind?
It creates different pressure areas where air wants to move from cool,dense, high pressure areas to warm, less dense, low pressure areas, speed depends on pressure gradient force.
Cool air also moves from the poles to the equator which then warms up and moves back to the poles.
How does the Coriolis effect, effect wind?
Earths rotation moves air to the right in the northern hemisphere and moves air to the left in the southern hemisphere.
Why does wind usually cross isobars at an angle?
Surface friction, that is why there is usually a wind direction change around 2000ft.
What are the different types of fronts?
•warm front
•cold front
•occluded front
•stationary front
What is a warm front? And what weather does it usually bring?
A Warm Front forms when a relatively moist, warm air mass slides up and over a cold air mass.
-stratiform clouds
-drizzle rain
-low ceilings
-poor visibility
What is a cold front? And what weather does it usually bring?
A cold front forms when a cold, dense air mass pushes under a warm, lighter air mass, forcing the warm air to rise.
-Towering Cumulonimbus clouds
-Heavy rain
-Temp drops
What is an occluded front? And what weather does it bring?
An Occluded Front forms when a warm air mass gets caught between two cold air masses.
-strong winds
-heavy precipitation
-form in mature low pressure areas
What is a stationary front and what weather does it bring?
Stationary fronts occur when the forces of two air masses are relatively equal, causing the front not to move.
-cloudy
-steady precipitation
-can often last days
What are the types of Low clouds (below 6000ft)
•Stratus
-layered, stable
•Nimbostratus
-thick, contain moisture
•Stratocumulus
-puffy, stable air is lifted
What are the types of mid level clouds?
•Alto stratus
-flat, can contain icing
•Alto cumulus
-Patchy
-Light turbulence, icing
What are the types of high level clouds?
•Cirrus
-Ice crystals above 36,000
•Cirrostratus
-Thick, No icing
•Cirrocumulus
-cotton, Light turbulence
What are the different types of Thunderstorms (SSEAAL)
Severe
Steady state
Embedded
Airmass
Area thunderstorm
squal Line
What is a severe thunderstorm?
Convective sigmet
-3/4 hail
-50kt wind or greater
What is a steady state thunderstorm?
the mature stage may then become a “steady state” thunderstorm cell in which extreme turbulence and large hail may predominate.
What is an embedded thunderstorm?
A thunderstorm embedded in clouds so it is not visible without radar if in IMC.
What is an Area Thunderstorm?
A thunderstorm 40% of 3000sq miles.
What is an Air mass thunderstorm?
Generally, a thunderstorm not associated with a front or other type of synoptic-scale forcing mechanism.
What is a squal line?
A “squall line” refers to a linearly-oriented zone of convection. Usually in front of a cold front.