Ch 21 - Reporting And Forecasting Flashcards
ICAO Annex 3
The mothership of all other weather forecasting
Meteorological Service for International Air Navigation
Works with WMO to review the requirements for aviation
WMO
World Meteorological Organization
Based in Switzerland
Ensures that all met services follow ICAO annex 3
Provides products and services to contribute to the safety and efficiency of aviation industry, internationally and nationally
Works with the ICAO Anex 3 to review the requirements for aviation
WAFS
World Area Forecast System
Provides meteorological authorities and other users with global aeronautical meteorological en-route forecasts
There are 6: WAFC Aerodrome Met. Offices MWO Aeronautical Met. Centres Ash Advisory Centre TCAC
WAFC
2; London - met office (Exeter), Washington - NOAA
Provide global upper weather forecasts
Med - High SIGWX
Aerodrome Met. Offices
Provide the aerodrome forecasts
Provide regional airfield briefings
MWO
Met. Watch Offices
Responsible for SIGMET and AIRMET reports
Aeronautical Met. Centres
Responsible for METARS
Ash Advisory Centre
Responsible for advisory information on volcanic ash
TCAC
Tropical Cyclone Advisory Centres
Provide advisory information on tropical cyclones when the maximum of the 10-minute mean surface wind speed is expected to exceed 17m/s (34kt) during the period covered by the advisory
Aerodrome Warnings
Surface warnings
Valid for 6 hours
Sequentially numbered through out the day
Issued when bad weather is present/expected.
Includes every type of inclement weather
Windshear Warnings and Alerts
Measured on the ground using apparatus - LLWAS (low level windshear alert system)
Windshear can be present if; inversion, TS, micro/macro bursts, fronts, sea/land breezes
Sequentially numbered
Alerts only come from automated Windshear systems
Updated every minute (EASA)
Preflight Planning
Look at all of the reports
In an airline it is the responsibility of the operators
For private flying it is down to you.
GAMET
General Aviation Met. Area Forecast
6 hours
Contain info about certain wx below FL100 (LL forecast)
Up to FL150 in mountainous areas
In support of SIGMETs and AIRMETs
Broken into 2;
1 - Surface wind / vis/ SIGWX/ Cloud/ Turb. (General info)
2 - Pressures/ Pressure Systems/ wind/ cloud (more specific)
GAFORS
General Aviation Forecasts
6 Hours
Info on visual flight conditions
- Cloud base/ceiling
- Visibility
4 categories O-open D-difficult M-marginal X-closes
SIGMETs
Significant Met Information
MWO (Met Watch Offices)
Details on any occurring/expected significant/dangerous wx
All flight levels considered
4 Hours unless tropical cyclone/volcanic ash clouds in which case it is 6 hours
EASA - Cyclone = 12h, Ash = 6 hours
Sequentially numbered
Cancelled when not relevant anymore
Contain every wx type which is either heavy or severe
SEV MTW
Isolated TS never included on SIGMET
AIRMETs
MWO (Met. Watch Offices)
GAMMETs - LL wx effecting the safety and efficiency of flight
Valid for 4 hours
Can be cancelled
Conditions not as hazardous:
Isolated TS, Mountain OBSC, Clouds 1000ft AGL, MOD ice/turb, MOD MTW
METARS
Meteorological Aerodrome Report
Updated every 30 minutes
Valid at the time of observation
If SIGWX change/corrected - SPECI will be issued and if the conditions change into dangerous enough ones SIGMET will be issued
Mean wind speed in METARs is averaged out over the last 10 minutes
Gust will be an individual wind that is 10kts more than the mean
Cloud Ceiling
The main cloud base AGL
Lowest layer of the cloud that is below 6000m(20000ft) or MSA which ever is higher.
Covering more than half of the sky (BKN or OVC)
RVR Decoded
After RVR;
U=Increasing
D=Decreasing
N=No change
Before RVR:
P=More than
M=Less than
V = Significant Variations
VC = in the vicinity of 8km
TAFs
Issued every 6/9 hours and then reissued every 3 hours.
Can also be 12/24/36 hour TAFs which are updated every 6 hours
TEMPO
Last for half an hour within an hour within the specified time
TX
Max. Temp Turing the forecasted period
TM
Minimum temperature during the forecasted period
NEVER ASSUME WITH TAFs or METARS
no RVR
TAF issued and also TAF Amendments can be issued
BECMG
Means the weather changes from before this time
It will occur at some point between the times specified
Do not assume in the middle, could be at 1 minute to the specified time
PROB30/40
30% change of occurring
40% change of occurring
If in a question it asks for most likely - do not take into account anything with PROB involved
If the question asks for expected, you can use the information given in the PROB30/40
Tropical Cyclone Advisory Centres (TCAC)
Information on cyclones
Start reporting them when they are >34kts (17m/s)
Volcanic Ash Advisory Centre
Information on volcanic ash and activity - Shown on graphical charts or SIGMETS
There are 9 of these around the world
SNOWTAM
Report on the presence/removal of contaminants/hazardous conditions; water, snow, ice, slush, or anything else on the RW
Valid for 24 hours
And whether or not they are removing the contaminant
ASHTAM
Valid for 24 hours
Reports on volcanic activity and any ash clouds
Surface Pressure /Weather Charts
Lines = Isobars (QFF)
Gaps between isobars = Windspeed
Col - between 2 highs and 2 lows
Warm Occlusion - most common in winter
Updated every 6 hours
And forecast 24,36,48,72 hours ahead with decreasing accuracy
SIGWX
Solid black line shows jet stream speed and height
Scalloped Box shows you areas of SIG WX and will have a box telling you all about it
CB - indicates severe ice and turbulence
Boxes with number in it is the tropopause height
Box with a roof and H shows you the highest level tropopause in the region
Box with roof on the bottom shows lowest level of the tropopause in the region
3 Different Levels of a SIGWX
Low level
SIGWX Charts Show the following
TC MOD/SEV TURB MOD/SEV Icing \+DZ and SS CB and TS if: cover is more than 50%, SQL, EMB, OBSC, ISOL, OCNL, FRQ
Tropopause Heights Jet streams (have to be >80kt) RDACTIVE material Fronts Convergence Zones ITCZ VA
Jet Stream
Has to be above 64kts to be counted as a jet stream and above 80kts to be shown on a SIGWX
Will be shown with height of core
Where max speed >120kts, vertical extent is also shown
Double Bar shows that there has been a speed change of <20kts and / or a height change of <3000ft
Solid Arrow shoes a speed change of >20kts and or a level change of >3000ft
In Flight Meteorological Broadcasts
ATIS
D-ATIS
ATIS
Automated Terminal Information Service
Current actual weather included wind (magnetic) over a two minute average Traffic INfo RW conditions General Warnings Additional Operational Info
If it is the first flight of the day you need to report which ATIS you are working from to start with - change every 30 minutes
METARS direction
TRUE and every 10 minutes
ATS
Aerodrome Traffic Services
Instant Conditions and orientated to the Magnetic north
D-ATIS
Data-link Automated Terminal Information service
Same information as the ATIS but comes through the ACARS
VOLMET - Continuous
VHF (very high frequency)
Continuous METARS with trends (up to two hours after report) and SPECIS
VOLMET - Scheduled
HF (high frequency)
METARS with trends
SPECI
TAF
SIGMET
D-VOLMET
ACARS (Datalink) METARS with trends SPECI TAF SIGMET Special Air Reports AIRMET where available
How many stations are allowed on each VOLMET frequency
There will be up to 10 stations (airfields) allowed on each frequency
The frequencies will be found on the aeronautical information publication (AIP)
SNOCLO
RW closed due to snow / contaminants
AMDAR
Aircraft Meteorological Data Relay System
The WMO - World Meteorological Organisation
It is a system / collection of all the met conditions from all the AC/commercial operating collected from DATALINKS
Routine AC Observation
Comes from AC with ACARS
Conditions are observed and recorded encounter and in climb out phases of flight
AC ID, Routine Report Position Time Windspeed Humidity
Special AC Observations
Can come from any time in flight
Any communication either from ACARS or Voice communications
They report significant WX; MOD/SEV TURB MOD/SEV Ice SEV MTW TS +/- GR (not isolated) \+DS and +SS VA or eruption activity
Radiosonde
An instrument sent up on a weather balloon and measures:
Humidity
Temperature
Pressure
If it is fitted with a GPS; it can also measure the wind speed and direction
Tephigram
Shows all of the energy in the atmosphere - the stability levels of the atmosphere
Set Lines on tephigram: Pressure Levels DALR SALR Dew Point Temperature Lines
The ELR will be plotted which is collected from the radiosonde
