Weather Information Flashcards
To determine that the applicant exhibits satisfactory knowledge, risk management, and skills associated with weather information for a flight under VFR.
Weather Data for Flight Planning
NWS, Foreflight, https://www.aviationweather.gov, 1–800–WX–BRIEF
Briefing Packages
Outlook (more than 6 hours out)
Standard
Abbreviated (update to standard)
Standard includes:
- Weather synopsis
- Sky conditions (clouds)
- visibility and weather conditions at departure, en route, and destination points
- Adverse Conditions
- altimeter settings
- cloud tops
- dew point
- icing conditions
- surface winds
- winds aloft
- temperature
- thunderstorm activity
- precipitation
- precipitation intensity
- visibility obscuration
- pilot reports (PIREP)
- AIRMETs
- SIGMETs
- Convective SIGMETs
- NOTAMs
- TFRs
METARs
METeorological Aerodrome Reports:
A typical METAR contains data for the temperature, dew point, wind direction and speed, precipitation, cloud cover and heights, visibility, and barometric pressure. A METAR may also contain information on precipitation amounts, lightning, and other information that would be of interest to pilots or meteorologists such as a pilot report or PIREP, colour states and runway visual range (RVR).
In addition, a short period forecast called a TREND may be added at the end of the METAR covering likely changes in weather conditions in the two hours following the observation. These are in the same format as a Terminal Aerodrome Forecast (TAF).
TAF
terminal aerodrome forecast (TAF) is a format for reporting weather forecast information,[1] particularly as it relates to aviation. TAFs are issued at least four times a day, every six hours, for major civil airfields: 0000, 0600, 1200 and 1800 UTC,[2] and generally apply to a 24- or 30-hour period, and an area within approximately five statute miles from the center of an airport runway complex. TAFs are issued every three hours for military airfields and some civil airfields and cover a period ranging from 3 hours to 30 hours.
AIRMET
Airmen’s Meteorological Information, is a concise description of weather phenomena that are occurring or may occur (forecast) along an air route that may affect aircraft safety.
SIGMET
SIGMET, or Significant Meteorological Information AIM 7-1-6 , is a weather advisory that contains meteorological information concerning the safety of all aircraft. There are two types of SIGMETs: convective and non-convective.
Non-convective - severe or greater turbulence, icing, IMC (instrument meteorological conditions) due to dust, sand, or volcanic ash. Valid of up to four hours. Issued as needed. Outside the Contiguous United States they are valid for up to 6 hours.
Convective - issued for embedded thunderstorms, a line of thunderstorms, a lot of thunderstorms, or severe surface weather including windows gte 50 knots. Issued hourly at hour+55 and is valid for 2 hours.
Stratiform Cloud
very little vertical development
Cumulus Cloud
vertical development
Cumulus Nimbus Cloud
associated with thunderstorms
Cirrus Cloud
high alt. clouds (little weather, no ice)
Along a Warm Front you find…
Stratiform Clouds, poor viz, widespread precipitation
Along a Cold Front you find…
Cumulus or cumulus nimbus clouds, good viz, showery precipitation
Low Pressure Fronts
front rotate counter clockwise from these systems, unstable
High Pressure Fronts
more stable, windows come off high pressure fronts clockwise
Occluded Front
a cold front overtaking a warm front, will become like the dominate front (usually the cold front)
Stationary Front
an occluded front that lost energy
Trough
an elongated low pressure system
Ridge
an elongated high pressure system
isobars
lines of equal pressure
Standard Lapse Rate
3.5F per 1000 feet
Unstable Lapse Rate
Unstable Atmosphere
Microbursts
A microburst is an intense small-scale downdraft produced by a thunderstorm or rain shower.
Mountain Wave
air forming waves as it goes off a plane, imagine air waving. Can exceed the capabilities of the airplane. 2000 feet around mountain it’s bad
Rotor clouds form from mountain waves close to the mountain
standing lenticular cloud (lens shaped) further away and at altitude
Windshear is found near
high wind of obstacles or terrain, temperature inversions, frontal activity, storms
- might cause a sudden change in airspeed or vertical speed
Thunderstorms form when
unstable lapse rate, high moisture, lifting action
Encountering a Thunderstorm
avoid by 20nm or if inside keep flying in the same direction, don’t concern with altitude variation, secure everything, turn interior cabin lights on (so not blinded by lightning)
Levels of Turbulence
Light, moderate, severe, extreme
Moderate Turbulence
Momentary loss of control
Severe Turbulence
loss of control / difficult to control / displacement of objects in captain
Freezing Level
The altitude in which the temperature reaches freezing
Icing Conditions
visible moisture at or below freezing
Fog forms when
dew point and temperature within 3.5 degree Fahrenheit
radiation fog
ground cools, when air reaches dew point then we get fog
upslope fog
air rises up a mountain, as it rises it cools and condenses
advection fog
air moves from warmers surfaces to a cooler surface
frost sublimation
water goes from gas / vapor to solid skipping liquid
limitation of digital weather systems
weather is delayed
Inflight Weather systems
HiWAS, FSS, ATC, ADS-B, Weather Radar on Plane
HiWAS tuning
VORs with H, tune VOR freq and listen
