Weather Flashcards
Other weather sources?
Private industry (ForeFlight)
DUATS
Inflight FSS 122.2
Types of weather briefings
Standard- for flight planning with no other source of previous info
Abbreviated- supplement to mass disseminated data
Outlook- when flight is 6+ hours out
Inflight- update to preflight briefing
What Information should a wx briefing include?
ATC delays Synopsis Adverse conditions Current conditions Enroute forecast Destination forecast Winds Aloft Notams
Hint* A SACrED WiNd
What is HIWAS
Hazardous Inflight weather advisory service
Continuous broadcast of inflight wx including SIGMETS AIRMETS PIREPS.
What is ATIS?
Automatic Terminal Information Service
Continuous broadcast of recorded weather info in select high activity terminal areas
Relieves congestion and improves controller effectiveness
Hourly or special wx report
What is included in ATIS broadcast?
Time Ceiling Visibility Temperature Dew point Wind direction (magnetic) and velocity Altimeter Remarks Runways in use
What is a METAR?
Aviation routine wx report
Wx observation stage a given site and time
Type, station, date/time, wind, vis, rvr, wx phenomena, sky condition, temp/dew, altimeter, remarks
Describe various wx observing programs
AWOS
ASOS/AWSS
Manual observations
What are PIREPS?
Where are they found?
Two types?
Wx observed by pilots en route
Type, location, time, flight level,type AC, at least one wx element encountered
Urgent UUA
Routine UA
What are TAFs?
Terminal Aerodrome Forecasts
Meteorological conditions in 5 SM radius of airport for a specified time period
Valid 24 hrs, issued 4 times daily
What is an aviation area forecast?
FA is forecast if VMC, clouds, gen wx over an area the size of several states. Used to forecast ENROUTE wx.
3 times daily for 6 areas in the 48 states
What are inflight aviation weather advisories?
Convective SIGMET- significant wx hazardous to all aircraft having to do with thunderstorms. -surface winds 50+ -hail +3/4 in diameter -tornadoes -embedded thunderstorms -squall line -valid 2 hours SIGMET- non convective wx that is still potentially hazardous to all aircraft -severe icing -severe turbulence (CAT) -dust storms -volcanic ash AIRMET-significant wx of Lower intensity. Issued every 6 hours -Sierra (IMC or Mountain obscuration) -tango (mod turbulence, wind +30, LLWS) -Zulu (mod icing, freezing levels)
What is winds and temp aloft forecast? What can be determined?
Issued 4 times daily
Wind direction to true north
Wind speed in knots
Temperature Celsius
Most favorable Altitude
Areas of possible icing
Temperature inversions
Turbulence
What is convective outlook?
Graph displaying potential for convective activity for following 3 days. Defines areas of slight moderate and high risk of severe thunderstorms
What is a surface analysis chart?
pressure systems and fronts
Winds/temp/dew point
Issued every 3 hours
What is a radar summary chart?
Displays areas of precipitation, intensity, configuration, coverage
Does NOT display clouds or fog
What is a weather depiction chart?
Analysis of flying categories (IFR, MVFR, VFR)
Issued 8 times daily
What info do short range prognostic charts provide?
Pressure systems
Fronts
Precipitation
For a 2 day period
What are NOTAMs?
Notices to Airmen. Time critical, usually temporary in nature.
Airport or runway closures
Changes to NAVAIDS
ILSs
Radar service availability
(D)
FDC
Pointer Notams
Military Notams
What are the 2 major classifications of thunderstorms?
Air mass thunderstorms: surface heating in unstable air lasting only an hour or 2
Steady state thunderstorms: form in lines, last several hours, dump heavy rain and possible hail, strong gusty wind, possible tornadoes. Normally associated with weather systems and fronts
Do’s and Don’t’s of thunderstorms
Don’t take off or land in face of approaching thunderstorm
Don’t fly under thunderstorms
Don’t fly without airborn radar into cloud mass
Do avoid by 20 miles
Do clear top by 1000 ft per 10 kts
Do avoid entire area if 6/10 coverage
Frequent lightning indicates severe thunderstorms
Can ATC provide inflight weather avoidance assistance?
Yes, to an extent. Their primary responsibility is aircraft separation.
What are microbursts?
Small scale intense downdrafts that on reaching the surface spread out in all directions. Presence of both horizontal and vertical wind shear.
Not easily detectable
Characteristics of microbursts?
Size- less than 1 mile diameter as it descends and can extend 2.5 miles near ground level
Intensity- 6,000fpm and 90kt windshears possible
Duration- usually less than 15 minutes
What types of weather information will you examine to determine if microburst/wind shear conditions might affect your flight?
LLWAS reports - low level wind shear alert system
TAFs, METARs, SIGMETS
Define wind shear and state the areas in which it is likely to occur.
Rate of change of wind velocity (direction and/or speed) vertically or horizontally
Low level temperature inversions
Frontal zones or thunderstorms
Clear air turbulence
Why is wind shear an operational concern to pilots?
Unexpected changes in wind speed/direction can be very hazardous at low levels on approach to and departing from airports
What airplane characteristics will be observed in the following wind shear situations?
Sudden increase in headwind?
Sudden decrease in headwind?
Increased headwind- increase in airspeed and nose up pitching… your reaction would be to reduce power and pitch which would be dangerous if it goes back to a tailwind and/or downdraft
Decreased headwind - pitch and airspeed decrease and loss of altitude… reaction would be more power and pitch up to climb or remain on glide slope.
What is the LLWAS system?
Low level wind shear alert system
Compares winds measured by sensors on the periphery of an airport to with wind measures at the center of the airport. If the difference is excessive, wind shear is possible
Define IFR, MVFR, VFR.
Instrument flight rules
Ceiling - 1,000 vis -3 miles
Marginal VFR
Ceiling 1000-3000 vis 3-5 mi
Visual flight rules
Ceiling +3,000 ft vis +5 miles
What are the 3 stages of a thunderstorm and what conditions must be met for thunderstorm to form.
Lifting action, sufficient moisture, unstable lapse rate
Cumulus, mature, dissipating.
Occluded front?
When a fast moving cold front catches up with a warm front.
Warm front occlusion typically has more severe weather than cold front occlusion. Air ahead of warm front is colder than than the air of the cold front.
