Ch 21 - Reporting And Forecasting

Question 1

ICAO Annex 3

Answer 1

The mothership of all other weather forecasting

Meteorological Service for International Air Navigation

Works with WMO to review the requirements for aviation

Question 2

WMO

Answer 2

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

Question 3

WAFS

Answer 3

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

Question 4

WAFC

Answer 4

2; London - met office (Exeter), Washington - NOAA

Provide global upper weather forecasts

Med - High SIGWX

Question 5

Aerodrome Met. Offices

Answer 5

Provide the aerodrome forecasts

Provide regional airfield briefings

Question 6

MWO

Answer 6

Met. Watch Offices

Responsible for SIGMET and AIRMET reports

Question 7

Aeronautical Met. Centres

Answer 7

Responsible for METARS

Question 8

Ash Advisory Centre

Answer 8

Responsible for advisory information on volcanic ash

Question 9

TCAC

Answer 9

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

Question 10

Aerodrome Warnings

Answer 10

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

Question 11

Windshear Warnings and Alerts

Answer 11

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)

Question 12

Preflight Planning

Answer 12

Look at all of the reports

In an airline it is the responsibility of the operators

For private flying it is down to you.

Question 13

GAMET

Answer 13

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)

Question 14

GAFORS

Answer 14

General Aviation Forecasts

6 Hours
Info on visual flight conditions

• Cloud base/ceiling
• Visibility

4 categories 
O-open
D-difficult
M-marginal
X-closes

Question 15

SIGMETs

Answer 15

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

Question 16

AIRMETs

Answer 16

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

Question 17

METARS

Answer 17

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

Question 18

Cloud Ceiling

Answer 18

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)

Question 19

RVR Decoded

Answer 19

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

Question 20

TAFs

Answer 20

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

Question 21

TEMPO

Answer 21

Last for half an hour within an hour within the specified time

Question 22

TX

Answer 22

Max. Temp Turing the forecasted period

Question 23

TM

Answer 23

Minimum temperature during the forecasted period

Question 24

NEVER ASSUME WITH TAFs or METARS

Answer 24

no RVR

TAF issued and also TAF Amendments can be issued

Question 25

BECMG

Answer 25

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

Question 26

PROB30/40

Answer 26

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

Question 27

Tropical Cyclone Advisory Centres (TCAC)

Answer 27

Information on cyclones Start reporting them when they are >34kts (17m/s)

Question 28

Volcanic Ash Advisory Centre

Answer 28

Information on volcanic ash and activity - Shown on graphical charts or SIGMETS There are 9 of these around the world

Question 29

SNOWTAM

Answer 29

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

Question 30

ASHTAM

Answer 30

Valid for 24 hours Reports on volcanic activity and any ash clouds

Question 31

Surface Pressure /Weather Charts

Answer 31

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

Question 32

SIGWX

Answer 32

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

Question 33

3 Different Levels of a SIGWX

Answer 33

Low level

Question 34

SIGWX Charts Show the following

Answer 34

``` 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 ```

Question 35

Jet Stream

Answer 35

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

Question 36

In Flight Meteorological Broadcasts

Answer 36

ATIS D-ATIS

Question 37

ATIS

Answer 37

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

Question 38

METARS direction

Answer 38

TRUE and every 10 minutes

Question 39

ATS

Answer 39

Aerodrome Traffic Services Instant Conditions and orientated to the Magnetic north

Question 40

D-ATIS

Answer 40

Data-link Automated Terminal Information service Same information as the ATIS but comes through the ACARS

Question 41

VOLMET - Continuous

Answer 41

VHF (very high frequency) | Continuous METARS with trends (up to two hours after report) and SPECIS

Question 42

VOLMET - Scheduled

Answer 42

HF (high frequency) METARS with trends SPECI TAF SIGMET

Question 43

D-VOLMET

Answer 43

``` ACARS (Datalink) METARS with trends SPECI TAF SIGMET Special Air Reports AIRMET where available ```

Question 44

How many stations are allowed on each VOLMET frequency

Answer 44

There will be up to 10 stations (airfields) allowed on each frequency The frequencies will be found on the aeronautical information publication (AIP)

Question 45

SNOCLO

Answer 45

RW closed due to snow / contaminants

Question 46

AMDAR

Answer 46

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

Question 47

Routine AC Observation

Answer 47

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 ```

Question 48

Special AC Observations

Answer 48

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 ```

Question 49

Radiosonde

Answer 49

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

Question 50

Tephigram

Answer 50

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