Weather Information

Question 1

TAF (terminal aerodrome forecast)

Answer 1

• valid for 24 hours
• issued 4 times a day
• good within 5SM of airport
  Information contained:
  1. Station ID
  2. Day of the month and time in Zulu
  3. Wind
  4. Visibility
  5. Weather and obstructions to visibility
  6. Sky conditions
  7. Temp and DP
  8. Altimeter
  9. Remarks
• the source: FSS or DUATS

Question 2

FA (area forecast)

Answer 2

• forecast of visual meteorological conditions (VMC), clouds and general weather conditions over an area of several states
• issued 3 times a day
• valid for 18 hours
• 6 regions across the U.S.
  Comprised of 4 sections:
  1. Communications and product header
• time issued, validity, states covered
  2. Precautionary statement
• see airmet Sierra for mtn obscurement and IFR conditions
• thunderstorms imply severe or greater turbulence
• all heights are in msl unless denoted by AGL or CIL
  3. Synopsis
• brief summary of movement of fronts, pressure systems and circulation patterns
• valid for 18 hours
  4. VFR clouds and weather
• breaks each state into segments
• 12 hour cloud and weather forecast
  A. Sky condition
  B. Surface visibilities
  C. Weather
  D. Winds (20kts or greater)
• 6hr categorical outlook (VFR, IFR, MVFR)
  Source FSS or DUATS

Question 3

Surface analysis chart

Answer 3

• issued 8 times a day
• every 3 hours
• valid: observed data
• shows isobars, pressure systems, locations of fronts, troughs, and ridges, station plot models

Question 4

Wind shear report

Answer 4

• from LLWAS systems
• warning against possible wind shear
• measurements taken from different locations at an airport
• METARS, ATIS, or a PIREP on HIWAS

Question 5

Winds and temperatures aloft chart (FD)

Answer 5

• Issued 4 times per day
• valid for 6hrs
• 12hr forecast + 12hr outlook
• wind direction/velocity and temps aloft for altitudes between 3000’ and 39,000ft:
• winds are in true north
• temps is in C
• no winds reported w/in 1500’ of station
• no temps reported w/in 2500’ of station
• no temps at 3000’ level report
• altitudes are in msl
• 9900 winds are light and variable
• temps are always negative above 24,000’

Question 6

AWOS

Answer 6

• automated weather observation system
• robot voice on discrete frequency
• 4 types:
  1. AWOS A- altimeter only
  2. AWOS 1- AWOS A + winds, temp, and DP
  3. AWOS 2- AWOS 1+ visibility
  4. AWOS 3- AWOS 2 + clouds and ceiling
  Minute by minute updates
• most have telephone access

Question 7

Weather depiction chart

Answer 7

• issued 8 times a day
• valid for 3 hours
• current observation conditions
• taken off METER stations
• IFR/VFR (off DUAT)
• sky cover, precip, visibility (NOAA)

Question 8

ASOS (automated surface observation system)

Answer 8

• transmitted over a discrete VHF radio freq or the voice portion of a local NAVAID
• contains information identical to AWOS 3
• can also provide variable cloud heights
• variable visibility:
  ASOS 1: A01
• AWOS 3
  ASOS 2: A02
• AWOS 3+ precipitation discriminator
  Updated minute by minute

Question 9

ATIS (automatic terminal information system)

Answer 9

• continuously broadcasted prerecord message of current airport weather and airport data
• obtained by local AWOS or ASOS if at a non controlled airport
  Broadcast contains:
• runways in use
• NOTAMS (closed runway, temp obstructions, etc)
• labeled with a letter of the phonetic alphabet so controller knows pilot has the current info

Question 10

Significant weather prognostic charts

Answer 10

• low level or high level prognostic chart
  Low level:
• forecast significant weather surface to 24,000’
• issued 4 times per day every 6 hours
• valid 24 hours
• depicts low level visibility and ceiling (1000-3000’ or below vid 3-5 SM or below)
• moderate to severe turbulence
• freezing levels
• divided into 4 boxes
• top boxes- severe weather at 12hr and 24hr forecast
• Bottom boxes- surface conditions at 12hr and 24hr forecast
• depicts pressure systems, fronts, and precipitation

Question 11

NOTAMS (notice to airman)

Answer 11

• time critical information which is either temporary in nature or is not known far enough in advance to permit publication on aeronautical charts or other publications
• DUATS, 1800wxbrief, ATIS
• NTAP- notice to airman publication:
• issued every 28 days
• contains all current NOTAMS (not included TFR’s)

Question 12

SIGMETS (WS) significant meteorological information

Answer 12

• unscheduled
• valid 4hrs (6hrs for hurricanes)
• reports non-convective weather which may effect safety of flight
• weather not associated with a thunderstorm
  Consists of:
• sever or greater turbulence or CAT (not associated w/T-storms)
• severe icing (not associated w/T-storms)
• widespread dust, volcanic ash, or sandstorms that reduce visibility to less than 3SM
• volcanic eruptions

Question 13

AIRMETS (airman’s meteorological information)

Answer 13

• issued 4 times a day
• valid 6hrs
• observed or forecasted weather that may effect safety of flight
• applies to all A/C but more pertinent to small AC
  3 types:
  1. Tango (turbulence)
• moderate to severe turbulence
• surface winds greater then 30kts sustained
• non convective LLWS
  2. Sierra (mountain)
• IFR conditions and extensive mountain obscurations
  3. Zulu
• freezing levels and icing conditions

Question 14

Convective SIGMETS (WST)

Answer 14

• issued hourly (55 minutes past the hour or special issue at any time)
• valid 2 hours
• hazards to all AC
  Consists of:
• bad weather associated with a T-storm
• lines of T-storms, squall lines
• T-storms over a wide area (60NM)
• embedded T-storms
• tornados
• hail 3/4” in diameter at surface
• surface winds at or above 50 KTs

Question 15

METAR (aviation routine weather report

Answer 15

• observation of current surface weather at airport environment
• valid for 1 hour
• issued hourly- 50-55 minutes past the hour
  Information contains:
  1. Station ID
  2. Day of the month and time in Zulu
  3. Wind
  4. Visibility
  5. Weather and obstruction to visibility
  6. Sky conditions
  7. Temp and DP
  8. Altimeter
  9. Remarks