WAFSOPSG/5-WP/20
International Civil Aviation Organization
23/6/09
WORKING PAPER
WORLD AREA FORECAST SYSTEM OPERATIONS GROUP (WAFSOPSG)
FIFTH MEETING
Paris, France, 16 to 18 September 2009
Agenda Item 6: Development of the WAFS
6.2: Visualization of WAFS forecasts
DISTRIBUTION OF WAFS FORECASTS ON ICAO APPROVED SYSTEMS
(Presented by the WAFC Provider States)
SUMMARY
This working paper discusses the proposed distribution of automated WAFS
forecasts, including those in the GRIB 2 code format, on ICAO approved
distribution systems..
1.
INTRODUCTION
1.1
Conclusions 4/20 of the WAFSOPSG/4 Meeting called on the WAFC Provider States to
develop a web-based distribution of automated WAFS SIGWX forecasts for the intended use in flight
documentation. The new web-based service (one from each WAFC) would provide objective gridded
forecasts of icing, turbulence and CB clouds, derived from GRIB 2 code-form WAFS forecasts. In
addition, Conclusion 4/14 of the last meeting, in discussing the introduction of gridded forecasts of icing,
turbulence and CB clouds, called on the WAFC Provider States to design products with a high “at a
glance” value. These forecasts do not have to replicate the existing SIGWX forecasts; however, they
must provide the same ease of use. In developing the web based distribution of WAFS forecasts, the
WAFCs have paid due consideration to the creation of ‘high-at-a-glance’ SIGWX (HG-SIGWX) forecasts
based on GRIB 2 WAFS data.
1.2
In addition, the GRIB 2 transition plan endorsed by the WAFSOPSG/4 Meeting
(Appendix F to the final report of the WAFSOPSG/4 Meeting refers) invited the WAFC Provider States
to make available GRIB 2 code-form WAFS forecasts (for wind/temperature and icing/turbulence/CB
clouds) available on ISCS and SADIS FTP services in parallel with GRIB 1 by September 2009.
1.3
This working paper outlines which automated WAFS forecasts will be available on which
ICAO approved distribution systems.
(9 pages)
106739107
WAFSOPSG/5-WP/20
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1.4
The group is invited to note that, at time of writing (June 2009), no decision has been
taken by the WAFSOPSG relating to the distribution of GRIB 2 WAFS forecasts on the ISCS and SADIS
satellite broadcasts.
2.
WAFS FORECASTS AVAILABLE ON THE WAFC
LONDON AND WAFC WASHINGTON WEB SERVICES
2.1
WP15 to this meeting, and the accompanying Progress Report, outlines the intended
range of WAFS graphical products to be made available on the WAFC London and WAFC Washington
web services.
2.2
The WAFS forecasts listed in Appendix A to this paper are a reproduction of the proposal
in the Progress Report of WP15. Subject to endorsement by the WAFSOPSG/5 Meeting, these products
will be available to authorised SADIS and ISCS users on each of the WAFC London and WAFC
Washington web services in chart form.
2.3
Table 1 in Appendix A contains a list of the forecasts for icing, turbulence and CB
clouds. Table 2 in Appendix A contains a list of the HG-SIGWX forecasts for high- and medium-level
flight operations (HG-SWH and HG-SWM). These charts are automatically generated from GRIB 2
code-form data from each respective WAFC. These forecasts are not amended or corrected. In
accordance with Annex 3 Appendix 8, chart areas A, B, B1, C, D, E, F and M are Mercator projection;
whilst chart areas G, H, I, J, K, L and EUR are Polar-Stereographic projection.
2.4
Data will be available four times per day, based on the 0000, 0600, 1200 and 1800 UTC
global models runs of the UK Met Office (WAFC London web service) and US NCEP (WAFC
Washington web service). As a minimum, users will require suitable public Internet web browsing
capability in order to view these forecasts.
2.5
Product issue time, requests for authorised access, and the web URL addresses, will be
communicated to users via the WAFS Change Implementation Notice Board and administrative
message(s).
3.
WAFS FORECASTS AVAILABLE ON THE ISCS AND
SADIS FTP SERVICE
3.1
In view of the information contained in WP/14, and its accompanying Progress Report,
the group is invited to consider whether the WAFCs should make available (on their FTP servers) the
forecasts for icing, turbulence and CB clouds in the GRIB 2 code form, in addition to wind, temperature,
humidity and tropopause GRIB 2 data. The icing, turbulence and CB clouds data could, if required,
populate a specific FTP folder called “GRIB2 trial forecasts” or similar.
3.2
The WAFS forecasts listed in Appendix B to this paper are intended to be available to
authorised users on the ISCS and SADIS FTP services in the GRIB 2 code form. Table 1 in Appendix B
outlines the wind, temperature, humidity and tropopause forecasts; whilst Table 2 in Appendix B outlines
the new icing, turbulence and CB clouds forecasts.
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WAFSOPSG/5-WP/20
3.3
These WAFS forecasts are in gridded binary format, based on a regular 1.25*1.25 degree
(unthinned) grid. Bulletins will contain a global field of data for each element. These forecasts are not
amended or corrected.
3.4
Users will require a production platform (i.e. ISCS or SADIS workstation) with suitable
visualisation software in order to view these gridded binary products.
3.5
WAFC Washington GRIB 2 WAFS data will be available on ISCS FTP four times per
day based on the 0000, 0600, 1200 and 1800 UTC runs of the US NCEP global model, valid for T+6 to
36 at 3-hourly timesteps.
3.6
Similarly, WAFC London GRIB 2 WAFS data will be available on SADIS FTP four
times per day based on the 0000, 0600, 1200 and 1800 UTC runs of the UK Met Office global model,
valid for T+6 to 36 at 3-hourly timesteps.
3.7
In total, 1078 GRIB 2 WAFS bulletins would be available every 6 hours if both the
wind/temperature/humidity/tropopause data and icing/turbulence/CB clouds data were provided on FTP
servers. WMO bulletin headers for products listed in Appendix B are available at Chapter 1d) of Annex 4
of the SADIS User Guide, via URL: http://www.icao.int/anb/sadisopsg/sug/sug_annex4.pdf.
3.8
Product issue time and host FTP addresses will be communicated to users via the WAFS
Change Implementation Notice Board and administrative message(s).
3.9
Subject to further endorsement by the group, WAFC London expects to make available
the GRIB 2 WAFS forecasts on SADIS FTP between September and December 2009. In addition,
WAFC Washington is in the process of developing a File Server to provide WAFS products in lieu of the
NWS FTP Server that is used for ISCS. This service is expected to be operational March 2010, and will
include the agreed specification determined by the WAFSOPSG/5 Meeting.
4.
CONCLUSIONS
4.1
As outlined in paragraph 2.1 to 2.5 above, the agreed product set to be included on the
WAFC web services is discussed in detail within WP/15, where an appropriate conclusion has been
drafted for the groups consideration.
4.2
In view of the discussion in paragraphs 3.1 to 3.9 above, and the information and
recommendations contained within WP/14, WP/15 and their respective progress reports, the group is
invited to formulate the following draft conclusion with regards the provision of GRIB 2 WAFS forecasts
on the ISCS and SADIS FTP servers:
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WAFSOPSG/5-WP/20
Conclusion 5/.. – Distribution of GRIB 2 WAFS forecasts on
ISCS and SADIS FTP services
That, the WAFC Provider States make available GRIB 2 WAFS
forecasts, as outlined in Appendix1 … to this report, on the ISCS
and SADIS FTP services by March 2010.
Note 1.— Gridded WAFS forecasts for
icing, turbulence and CB clouds are to be placed in a directory
marked “GRIB 2 trial data” or similar;
Note 2.— WAFC Washington is in the
process of developing a File Server to provide WAFS products in
lieu of the NWS FTP Server that is used for ISCS. This service is
expected to be operational March 2010; and
Note 3.— Product issuance time and host
FTP addresses are to be communicated to users via the WAFS
Change Implementation Notice Board at:
www.icao.int/anb/wafsopsg/WAFS%20change%20notice%20boa
rd.pdf
5.
5.1
ACTION BY THE WAFSOPSG
The WAFSOPSG is invited to:
a) note the information contained in this paper; and
b) decide on the draft conclusion for the group consideration.
————————
1
In Appendix B to this working paper.
WAFSOPSG/5-WP/20
Appendix A
APPENDIX A
WAFS FORECASTS AVAILABLE ON THE WAFC LONDON
AND WAFC WASHINGTON WEB SERVICES
Note. — The products listed below are in chart form.
Table 1. WAFS forecasts for icing, turbulence and CB clouds.
Product description
Pressure
levels (flight
levels)
Standard
ICAO chart
areas of
coverage
Model run
data time
(UTC)
Forecast
time steps
Total
number of
products
per run
Maximum Icing
700 (100),
600 (140)
A, B, B1, C, D,
E, F, G, H, I, J,
K, L, M, EUR
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24
210
Maximum clear air
turbulence
300 (300),
250 (340),
200 (390)
A, B, B1, C, D,
E, F, G, H, I, J,
K, L, M, EUR
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24
315
CB horizontal extent
with colour-coded
ICAO height at CB top
n/a
A, B, B1, C, D,
E, F, G, H, I, J,
K, L, M, EUR
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24
105
Total number of WAFC London/WAFC Washington forecast charts per issue = 630
WAFSOPSG/5-WP/20
A-2
Appendix A
Table 2. “High-at-a-glance” SIGWX forecasts.
Product description
Flight levels
Standard
ICAO chart
areas of
coverage
Model run
data time
(UTC)
Forecast
time steps
Total
number of
products
per run
High-at-a-glance
SIGWX for HIGH
level flights
(HG-SWH)
250-630
A, B, B1, C, D,
E, F, G, H, I, J,
K, L, M, EUR
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21,
24, 27, 30,
33, 36
165
High-at-a-glance
SIGWX for MEDIUM
level flights
(HG-SWM)
100-250
A, B, B1, C, D,
E, F, G, H, I, J,
K, L, M, EUR
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21,
24, 27, 30,
33, 36
165
Total number of WAFC London/WAFC Washington forecast charts per issue = 330
WAFSOPSG/5-WP/20
Appendix B
APPENDIX B
GRIB 2 WAFS FORECASTS AVAILABLE ON THE ISCS AND SADIS FTP SERVICES
Note. — WMO headers for these GRIB 2 WAFS forecasts are available at Annex 4
of the SADIS User Guide (URL: http://www.icao.int/anb/sadisopsg/sug/sug_annex4.pdf)
Table 1. Wind, temperature, humidity and tropopause forecasts in the GRIB 2 code form.
Product description
Pressure levels (flight levels)
Model run
data time
(UTC)
Forecast time Total number
steps
of products
per run
U wind component
850 (050), 700 (100), 600 (140)
500 (180), 400 (240), 350 (270),
300 (300), 275 (320), 250 (340),
225 (360), 200 (390), 150 (450),
100 (530)
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
143
V wind component
850 (050), 700 (100), 600 (140)
500 (180), 400 (240), 350 (270),
300 (300), 275 (320), 250 (340),
225 (360), 200 (390), 150 (450),
100 (530)
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
143
Temperature
850 (050), 700 (100), 600 (140)
500 (180), 400 (240), 350 (270),
300 (300), 275 (320), 250 (340),
225 (360), 200 (390), 150 (450),
100 (530)
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
143
Relative humidity
850 (050), 700 (100), 600 (140),
500 (180)
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
44
Tropopause height
(ICAO)
n/a
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
11
WAFSOPSG/5-WP/20
B-2
Appendix A
Tropopause
temperature
n/a
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
11
Maximum U wind
component
n/a
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
11
Maximum V wind
component
n/a
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
11
Maximum wind
height
n/a
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
11
Geopotential height
of standard levels
850 (050), 700 (100), 600 (140)
500 (180), 400 (240), 350 (270),
300 (300), 275 (320), 250 (340),
225 (360), 200 (390), 150 (450),
100 (530)
0000, 0600,
1200, 1800
T+6, 9, 12,
15, 18, 21, 24,
27, 30, 33, 36
143
Sub-total number of GRIB 2 WAFS bulletins per issue = 671
WAFSOPSG/5-WP/20
B-3
Appendix B
Table 2. Icing, turbulence and CB forecasts in the GRIB 2 code form.
Note. — These WAFS forecasts are for trial and evaluation purposes only.
Product description
Pressure levels (flight levels)
Model run
data time
(UTC)
Forecast time steps
Total
number
of
products
per run
Mean icing
800 (060), 700 (100), 600 (140), 500
(180), 400 (240), 300 (300)
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
66
Maximum icing
800 (060), 700 (100), 600 (140), 500
(180), 400 (240), 300 (300)
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
66
Mean in-cloud
turbulence
700 (100), 600 (140), 500 (180), 400
(240), 300 (300)
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
55
Maximum in-cloud
turbulence
700 (100), 600 (140), 500 (180), 400
(240), 300 (300)
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
55
Mean clear air
turbulence
400 (240), 350 (270), 300 (300), 250
(340), 200 (390), 150 (450)
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
66
Maximum clear air
turbulence
400 (240), 350 (270), 300 (300), 250
(340), 200 (390), 150 (450)
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
66
CB horizontal extent
n/a
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
11
ICAO height at CB
base
n/a
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
11
ICAO height at CB top
n/a
0000, 0600,
1200, 1800
T+6, 9, 12, 15, 18,
21, 24, 27, 30, 33, 36
11
Sub-total number of GRIB 2 WAFS bulletins per issue = 407
— END —