Lesson 25 Flashcards
(27 cards)
Terminal Aerodrome Forecast (TAF)
a concise statement of the expected meteorological conditions significant to aviation for a specified time period within 5 SM of an airport.
TAFs issued by the NWS provide a forecast of what meteorological elements:
- wind
- visibility
- significant weather
- cloud and vertical obscuration
- non-convective low-level wind shear (LLWS)
What are the 3 forms of TAFs?
Routine, Amended, Corrected
Routine TAFs are issued _____ times a day. (provide the time intervals)
4; @ 0000,0600,1200,1800Z
When are TAFs amended?
whenever they become, in the forecaster’s judgment, unrepresentative of existing or expected conditions
Routine TAFs are valid for either ___ or ___ hour time periods.
24; 30
-Example: 0106/0206 (‘beginning day of the month, beginning hour UTC’/’ending day of the month, ending hour UTC’)
TAF Visibility
- 6SM = Visibility 6
- P6SM= Visibility more than 6
-will only go to 6, never a digit higher
TAF Visibility
- 6SM = Visibility 6
- P6SM= Visibility more than 6
-will only go to 6, never a digit higher
NSW
No Significant Weather
Decode:
WS020/12035KT
example of a non convective low level wind shear (LLWS)
included when a LLWS is expected within 2,000 ft of the surface
– “Low Level Wind Shear, Wind at Two Thousand, one two zero at three five”
TEMPO
used to indicate temporary fluctuations to forecast meteorological conditions
PROB30
- used to forecast a low probability (30 percent chance) of a thunderstorm or precipitation event and its associated weather elements (wind, visibility and/or sky condition)
- located within the same line as the prevailing condition group, continuing on the line below if necessary
- “a 30 percent probability between….”
SIGMETs, Convective SIGMETs, and AIRMETs are _________.
“inflight advisories”
Significant Meteorological Information (SIGMET)
a weather advisory concerning weather significant to the safety of all aircraft
- unscheduled product issued any time conditions reaching SIGMET criteria are occurring or expected to occur within a 4 hr period
- max valid period of 4 hrs
Significant Meteorological Information (SIGMET)
a weather advisory concerning weather significant to the safety of all aircraft
- unscheduled product issued any time conditions reaching SIGMET criteria are occurring or expected to occur within a 4 hr period
- max valid period of 4 hrs
Convective SIGMET (WST)
weather advisory concerning convective weather significant to the safety of all aircraft
- issued for thunderstorms
- issued hourly at 55 minutes past the hour
- valid for 2 hrs or until superseded by the next hourly issuance
Airmen’s Meteorological Information (AIRMET)
an inflight advisory concerning weather phenomena which are of operational interest to all aircraft and potentially hazardous to aircraft having limited capability because of lack of equipment, instrumentation, or pilot qualifications
AIRMET SIERRA
for IFR and extensive mountain obscuration
AIRMET TANGO
for moderate turbulence, sustained surface winds greater than 30 knots, and non convective low level wind shear (LLWS) potential
AIRMET ZULU
for moderate icing and freezing levels
How long are AIRMETs valid?
for no more than 6 hours
Center Weather Advisory (CWA)
an unscheduled weather advisory issued by CWSU meteorologists for ATC use to alert pilots of existing or anticipated adverse weather conditions within the next 2 hrs.
LOW IFR
defined as ceiling less than 500 ft AGL and/or visibility less than one statute mile
LOW IFR
defined as ceiling less than 500 ft AGL and/or visibility less than one statute mile
