Weather Information Flashcards
What are approved sources to obtain weather?
AC-00-45h 2-2
(Contracted by the FAA (federal aviation administration) and NWS (national weather service)
1. Federal Government (Aviationweather.gov)
2. Commercial weather information providers (ForeFlight)
METAR is?
PHAK 13
Aviation Routine Weather Report
Updates every hour
What is a TAF?
PHAK 13
Terminal Aerodrome Forecast
Usually shows 4 time slots of 0000, 0600, 1200, 1800 Zulu time
Valid from 24 hrs- 30 hrs.
What is AIRMET?
PHAK 13
Airmens Meteorological Information
Issued every 6 hours
Potentially hazardous to light aircraft
AIRMET codes
PHAK 13-11
S- IFR and MT obscuration.
T- Turbulence, strong surface winds, and low level wind shear
Z- Icing and freezing levels
What is a SIGMET
PHAK 13-12/AIM 7-1-6
Significant Meteorological
Non convective weather potentially hazardous to all aircraft
Not associated with thunderstorms
Valid for 4 hours or 6 hours for hurricanes
SIGMET Codes
AIM 7-1-6 UWS is urgent weather SIGMET N-W Excluding S,T, and Z No 2 different phenomena across the country can have the same alphabetic designator. CAT is clear air turbulence
SIGMET Phenomenas
SSSDV
AIM 7-1-6
- Severe Icing
- Severe Turbulence or CAT (clear air turbulence)
- Sandstorm surface visibility below 3 miles
- Dust storm surface visibility below 3 miles
- Volcanic ash
Convective SIGMET are valid for? Reason for issuance is?
6 thunderstorm reasons
AIM 7-1-6
2 hours
Severe thunderstorms due to:
1. Surface winds greater than or equal to 50 knots
2. Hail at surface greater than or equal to 3/4 in. in diameter
3. Tornadoes
4. Embedded thunderstorms
5. Line of thunderstorms
6. Thunderstorms producing precipitation affecting 40% or more of 3,000 sq.mi.
(Atmospheric Composition)
What is our atmosphere made of?
PHAK 12-2/AC 00-06b
78% nitrogen
21% oxygen
1% of Argon/Carbon Dioxide and other trace gases
What is the vertical structure of the atmosphere? Or what are the various atmospheres?
Earth surface to space
- Troposphere- vast majority of weather happens.
- Tropopause - up to 48,000 feet in height, but varies with season.
- Stratosphere - temperature gets warmer due to absorption of ultralight radiation
- Stratopause - gets up to negative 3 degrees Celsius.
- Mesosphere - gets colder
- Mesopause - down to negative 100 degrees Celsius.
- Thermosphere - temp increases with height
- Thermopause
- Exosphere - atoms an molecules escape to space, satellite orbit earth.
How does weather systems form?
Hydrologic cycle
Water to vapor rises
- Evaporation - liquid to vapor
- Transpiration - liquid from plants to vapor
- Sublimation - solid to vapor (snow, ice to vapor)
- Condensation - vapor condenses to a cloud
- Transportation - wind pushes it
- Precipitation - rain, snow, ice, mist… that falls to the earths surface
What are Air Masses?
00-06b 10-1
Is a large body of air with generally uniform temperature and humidity.
Source Region- is where an air mass originated from.
How many air masses are there and what are they?
00-06b 10-1 There are 5 types. 3 continental- which means dry air masses that developed over land. cA - Continental Arctic cP - Continental Polar cT - Continental Tropical 2 Maritime- which means moist air that developed over water. mP - Maritime Polar mT - Maritime Tropical
What are the type of fronts?
Cold front - cold air replaces warm air.
Speed - 20-35 mph… steeper frontal slope… cold fronts typically have violent wx.
Warm front - warm air replaces cold air.
10-25 mph… low ceilings, poor visibility, and rain.
Stationary front - when cold and warm pushes against each other.
Occluded front - cold front catches warm front and are moving in same direction.