Chair Report

COST ACTION 722
‘Short-range forecasting methods of fog, visibility, and low clouds’
Report by Silas Chr.Michaelides
Chairman of Working Group ii
(Establishing Forecasters Requirements and Customers
requirements for Low visibility and Stratus)
Odense, Denmark 13-16 November 2002.
Working Group ii (WGii) meetings were held on 13/11/2002, from 1400 till 2000, on
14/11/2002, from 0900 till 1800 and on 15/11/200 from 0900 till 1200.
1. Opening
On the 13/11/2002, the meeting of the WGii was opened by Mr Silas Michaelides acting as
he Chairperson of the Group. The Chairman welcomed the members of the group and each
one was asked to make a brief introduction of him/herself.
2.Participation to the Working Group ii meeting
The following lists the members of the WGii who participated in the meeting
Cyprus: A.Poyiadjis, S.Michaelides
France: M.Champagne, D.Tzanos
Poland: A. Glowacka, E. Olszewska
Finland: J.Julkunen, J.Kotro
Denmark: M.Steffenson
Switzerland: U.Sutter
Mr. B. Golding (U.K.) of WGi, participated and contributed to the meetings that were
held on 13 and 14/11/2002.
3. Meeting on 13/11/2002
The Chairman started the discussion on 13/11/2002 by reviewing one by one the tasks that
they were agreed to be accomplished during the Barcelona meeting.
3.1 Task 1. Investigation of feasibility for a Joint meeting with Cost719 on GIS.
This task was undertaken by Denmark - Michael Steffenson to be completed by end
September 2002. The task was accomplished and the Chairperson of Cost 719 will
present an invited lecture during the Workshop to be held in June 2003 in Leipzig.
3.2 Task 2. Collection and editing of Presentations to be published on Web site and
publication.
This task was undertaken by Cyprus - Silas Michaelides and Andreas Poyiadjis. It
became evident during the discussions that all the material will be placed on the Action’s
Web site and there will be no official printed publication of the presentations as such.
3.3 Task 3. Formulation of Questionnaire for Customers and dissemination to
countries.

This task was accomplished by Poland – A. Glowacka, E. Aszewska and M. Paradowski.
By end of July 2002, the questionnaires were completed and sent to the members of the
Cost Action 722, in accordance with the 2 nd MC meeting decision taken in Barcelona.
The questionnaire will be placed on the Web site.
3.4 Task 4. Processing and compilation of results of Questionnaire for Customers.
This task was accomplished by France - Michele Champagne and by end of October 2002
the results were available, as planned. A total of 24 questionnaires were processed and
the results of the analysis were presented by Ms Champagne. The results will be put on
the Web site, also.
3.5 Task 5 Formulation of Questionnaire for Forecasters and dissemination to
countries.
The task was undertaken by Finland – J. Julkunen and J.Kotro. By end of July 2002 the
questionnaires were completed and sent to the members of the Cost Action 722, in
accordance with the 2 nd MC meeting decision taken in Barcelona. The questionnaire will
be placed on the Web site.
3.6 Processing and compilation of results of Questionnaire for Forecasters.
This task was accomplished by Switzerland – U. Sutter and by end of October 2002 the
results were available, as planned. A total of 102 questionnaires were processed and the
results of the analysis were presented by Mr Sutter. The results will be put on the Web
site, also.
Closing the session on the 13/11/2002, the Chairman of the Working Group has stressed
his impression that the working group members functioned in a highly professional
manner and the prompt accomplishment of all the tasks was the result of the individual
members’ efforts but also of the entire group’s collaborative hard work.
The countries which responded to the questionnaires are tabulated in Appendix 1.
4. Meeting on 14/11/2002
4.1 Draft of the Recommendations
The results from the two questionnaires were evaluated during the meeting on
14/11/2002. Ms Champagne and Mr Sutter led the discussion on their respective findings.
The members discussed the findings and finalized their recommendations on the
Forecasters’ and on the Customers’ requirements. The recommendations are shown
separately in Appendices 2 and 3, respectively.
4.2 Web site issues
A number of issues with regard to the WGii contribution to the Web site were raised by
Mr Michaelides and discussed in detail. Because the working group realized that
technical advice was needed on this issue, the group invited Mr J.Bendix to help the
members in getting a more clear idea on this matter.
4.3 Future work - Assignment of tasks
With regard to future work for the WGii members, the plan agreed was largely based on
the forthcoming Workshop to be held in Leipzig in June 2003. It was decided to present 5
papers to the Workshop. Also, it was decided that the view on Forecasters’ and
Customers’ requirements should be supplemented by a survey of any existing literature

on the matter. The assignment of Tasks is shown analytically in Appendix 4 and a
calendar of planned activities is shown Appendix 5.
5. Meeting on 15/11/2002
5.1 Web Site issues
As mentioned above, during the preceding day, a number of questions were raised
regarding the planning, the procedures and various other issues associated with the
material to be placed on the Web site. Mr. J.Bendix who is the member responsible for
the Web page of the cost Action, was invited and presented his plans. The members of
the Working Group asked several technical and procedural issues and finally agreed on
the following:
Mr.Michaelides will provide Mr Bendix with a layout of the Working Group’s
contribution to the site. This layout will include separately the material presented during
the Barcelona and Odense meetings and it is shown in Appendix 6.
• If necessary, Mr Michaelides will ask each member to resubmit his/her
contribution in the format which is suitable to each member. In responding, each
member will exclusively indicate in his/her e-mail the following:
a. Title of the work,
b. Author(s) name(s),
c. e-mail address.
The above will be inserted in the web page and can be used by those interested in
order to directly communicate with the author(s), from the web page.
• Mr.Michaelides will act as the liaison between Mr Bendix and the members. If
necessary, each member will resubmit his/her contribution with the respective
information, as above, and Mr.Michaelides will forward them to Mr Bendix.
5.2 Presentation of Report to the MC
The Chairman of the Working Group presented to the members his draft report which
would subsequently be presented to the Management Committee. During the presentation
several improvements were proposed by the members and accommodated accordingly.
5.3 Matters to be raised to the Management Committee
It was decided that the following matters will be raised to the MC:
• Ask the MC that all member countries respond to a request by WGii to make
available any titles of publications or documents regarding the requirements of
Forecasters and/or Customers for fog and low cloud forecasting.
• How will the Workshop in June 2003 be organized.
• What will be the requirements for participation in the four new working groups
that will be formed according to the MoU.

Appendix 1
Countries which responded to the questionnaires.
Austria,
Bulgaria,
Cyprus,
Denmark,
Finland,
France,
Germany,
Hungary,
Poland,
Spain,
Switzerland,
United Kingdom

Appendix 2
RECOMMENDATIONS ON FORECASTERS’ REQUIREMENTS
It has been obvious that weather forecasters were enthusiastic in contributing in this
COST project. We had 102 questionnaires filled.
Three priority areas were determined: 1) Model related requirements, 2) Requirements on
observations and measurements, 3) Climatological requirements.
1) MODELS
(i) More useful products are required from the models regarding visibility
and low cloud. There are requirements for presentations in terms of cross
sections and finer vertical resolution maps. Also, forecasters require that
they have diagnostic fields (e.g. visibility, low cloud base, low cloud tops,
low cloud amount, low cloud phase e.g. freezing conditions).
(ii) Improved model performance is another requirement put forward by
forecasters. In particular forecasters are interested in improving the
performance of boundary layer models. They also require that boundary
layer models have higher vertical resolution.
2) OBSERVATIONS AND MEASUREMENTS
With regard to existing observations forecasters require:
(i) Higher density and more frequent observation to be available (both
spatially and temporary).
(ii) SYNOP, METAR, TEMP and satellite information to become more
frequently updated.
With regard to additional observations forecasters require:
(i) Observations from video cameras, profilers, satellite with “fog channel”,
satellite with higher resolution imagery, ceilometers, cloud radar, additional
visibility measurements, net radiation.
(ii) The frequency with which these additional observations would be
provided ranges from 0 to 15 minutes.
More issues are related to:
(i) Better information is required by the forecasters in understanding these
observations (especially on new platforms) , on the one hand, and in the
forecasting methods that make use of them, on the other hand. The latter is
related to a requirement for better understanding on the capabilities of
models used.
(ii) More automatic weather stations reporting humidity and temperature.
(iii) There is a particular requirement for more observations over the sea.
(iv) Improve the exchange of information between different states: more
information but also more quickly.
3) CLIMATOLOGICAL REQUIREMENTS
(i) Not enough sites have climatological information. More climatological
information is required and in particular information is need for more sites.
(ii) The information may be available but access to it is not easy, so there is
a demand that, if the climatological information is available, to be presented
to the forecasters.

(iii) Presentation of climatological information should be in the form of
diagrams and charts. Such presentations should be site specific. ( for which
site)
(iv) Forecasters are not sure what climatological information they should
need. So some further research is required to assist the forecasters to define
their climatological needs.
(v) There is a requirement for results on climatological info extracted by
proper numerical techniques from climatological archives (e.g.
climatological information from satellite data archives).

Appendix 3
RECOMMENDATIONS ON CUSTOMERS’ REQUIREMENTS
Customers have been segmented into 4 domains (groups). 1) Aviation, 2)Road,
3) Marine, 4) Public.
The requirements from the Aviation and Road Sectors are the strongest.
1) AVIATION SECTOR
The recommendations for the Aviation Sector were further segmented into different
categories:-
a) ICAO recommendations (including thresholds in Annex 3 both on standard and
recommended practices
(i) There is no need to improve the ICAO recommendations. There is rather
a need for improving their realization by the weather forecasters. This
implies that there is need to improve the forecasts to fulfill the ICAO
recommendations. ICAO recommendations seem to fulfill the needs of a
large part of customers (e.g. pilots) but not of some others (e.g. companies).
Aviation companies seems to be more demanding in terms of fog and low
cloud forecasts.
(ii) Aviation customers need direct forecasts of the parameters they actually
use (i.e. forecasts on RVR, forecasts for cloud base which are specific to
aerodromes or even specific to runways etc).
(iii) Another aspect is the accuracy of the forecast visibility and low cloud.
The findings regarding the accuracy required is given below.
(iv) Forecasts generally reflect points (e.g. aerodromes). However, there is a
need for spatially distributed forecasts on fog and low cloud.
(v) There is a need for improved schemes associating probabilities with
forecasts on low cloud and fog.
b) In-flight requirements (VFR)
(i) It is not clear from the questionnaires what are the VFR in-flight
requirements. However, some answers refer to the need of AIRMET and
GAMET and also to low level maps on fog and low cloud.
(ii) There is a requirement for spatial distributions type of forecasts for fog
and low cloud at the scale of 20 km for use by VFR flight.
c) In-flight requirements (IFR)
Cloud base is required as far as icing, turbulence, comfort and economy are
concerned. However, this is not well documented from the questionnaires
(only one answer was provided on this).
d) Leading time for forecasts . Period of validity
ICAO rules seem to be sufficient. However, improvement of the
dissemination time is recommended by some customers. Especially, air
traffic control requires special services regarding the period of forecasts, i.e.
shorter forecast validity.
e) Military requirements

It is acknowledged that military requirements for fog and low cloud are
more demanding than for commercial planes, but there was not sufficient
information to quantify this.
2) ROAD SECTOR
This sector involves various kinds of users (drivers, road authorities, rescue teams, big
haulage companies etc).
(i) In general, customers in this sector are interested in low visibilities in the
range from 0 to 200 meters. Most critical when visibility is less than 50
meters.
(ii) Customers are interested when visibility decreases very rapidly along
the road.
(iii) In mountainous areas there is a need for low cloud forecasting.
(iv) Fog forecasts are required on the road. Rather general forecasts are not
so important.
(v) Customers also require that such forecasts reach them directly (e.g. by
broadcasting them over the radio or by road signs).
(vi) There are two requirements regarding the leading time
- The first one refers to nowcasting i.e. of the order of few
hours or even less (increasing requirement on the nowcasting
scale).
- The second refers to one day in advance.
(vii) The provision of the forecast time for fog dissipation is recommended.
(viii) There is a requirement for freezing fog forecasts (not necessarily
linked to low visibility).
3) MARINE SECTOR
There is not enough information to consolidate recommendations. However, the working
group has noted the existence of publication WMO Handbook for Offshore forecasting
WMO/TD N850.
Some general recommendations are:
(i) Ships at sea require forecasting of low visibilities in the range of 0 to 1
km.
(ii) Port Authorities require more detailed information on fog conditions and
forecasts but they do not specify exactly what they mean.
4) PUBLIC SECTOR
There is a general need for forecasts for fog and low cloud up to one day in advance.

Appendix 4
The table below summarizes the tasks undertaken by members of Wgii until the end of
the group’s mandate:
Appointment
task 1
task 2
task 3
task 4
task 5
task 6
Name
Prepare a list of
available documents
or existing literature
on Forecasters’ and
Customer’s
requirements.
Preparation of
recommendations
reached by WGii and
submission of Chair
report.
All material to be
compiled and sent to
the web site.
Preparation of
presentations to the
Workshop in June.
Results of
Questionnaires on
Customers’ and
Forecasters’
requirements.
Preparation of
presentations to the
Workshop in June.
Two “case studies”
on Forecaster’s and
Customers’
requirements.
Summary of
recommendations
from forecasters’ and
customers’ to be
presented at the
Workshop in June.
Country-Expert(s)-
Completion Month
Denmark: Michael
Steffenson, first week
of February 2003
Cyprus: Silas
Michaelides: send
comments to
members by end of
November 2002. All
members to sent
comments to
S.Michaelides, mid
December 2002
Cyprus: Silas
Michaelides and
Andreas Poyiadjis,
mid February 2003
France:
Michele Champagne
and Switzerland:
Urs Sutter, beginning
of May 2003
Finland: Jukka
Julkunen and
Poland:
Agnieszka Glowacka,
E. Olszewska and
Michal Paradowski,
beginning of May
2003
Cyprus: Silas
Michaelides,
beginning of May
2003

Appendix 5
The calendar of planned activities:
Dissemination by chair of draft report to End of November 2002
members for comments.
Dissemination by all members of all
comments to chair and submission of final
chair report.
Mid December 2002
Compilation and dissemination of existing First week of February 2003
literature and documentation of Forecasters’
and customers’ requirements.
Submission of all material to the Web site Mid February 2003
Preparation
Workshop.
of presentations to the Beginning of May 2003
1 st Workshop. Leipzig 10+11 June 2003
WG (1,2,3,4) meetings. Leipzig 11+12 June 2003
MC meeting. Leipzig 13+14 June 2003
MC and WG (1,2,3,4) meetings (tentative) November 2003

Appendix 6
Structure of the WGii Web page contents.
Cost Action 722
Working Group ii
----------------------------------------
A. Barcelona Meeting 13-15 June 2002
Chair Report Silas Michaelides silas@ucy.ac.cy
Cyprus
Fog, low visibility and
low cloud forecasting
France
Main user's
requirements
concerning fog and low
visibility forecasting
Poland
Report on the current
works of WGII COST
722 in Poland
Finland
FMI contribution to
WGii first report
Hungary
Report on the current
works of WGII COST
722 in Hungary at the
Hungarian
Meteorological Service
(HMS)
Denmark
COST 722 ”Shortrange
forecasting
methods of fog,
visibility and low
clouds”
Switzerland
COST 722 WG ii
MeteoSwiss
United Kingdom
Met Office
requirements for fog &
low cloud forecasts
Kleanthis Nicolaides
and Andreas Poyiadjis
forecast@cytanet.com.cy
forecast@cytanet.com.cy
M. Champagne michele.champagne@meteo.fr
A. Glowacka,
E. Aszewska and
M. Paradowski
J. Julkunen,
J.Kilpinen and
J.Kotro
agnieszka.glowacka@imgw.pl
edita_olszewska@imgw.pl
michal_paradowslu@imgw.pl
jukka.julkunen@fmi.fi
juha.kilpinen@fmi.fi
janne.kotro@fmi.fi
V. Sandor sandor.v@met.hu
M. Steffenson mist@dmi.dk
U. Sutter usu@meteoswiss.ch
B. Golding bgolding@metoffice.com

B. Odense Meeting 13-16 November 2002
Chair Report S. Michaelides
Questionnaire for
Forecasters’
Requirements
Report on
Questionnaire for
Forecasters’
Requirements
Questionnaire for
Customers’
Requirements
Report on
Questionnaire on
Customers’
Requirements
List of literature and
publications on
Forecasters’ and/or
Customers’
Requirements
J. Julkunen and
J.Kotro
silas@ucy.ac.cy
jukka.julkunen@fmi.fi
janne.kotro@fmi.fi
U. Sutter usu@meteoswiss.ch
A. Glowacka,
E. Aszewska and
M. Paradowski
agnieszka.glowacka@imgw.pl
edita_olszewska@imgw.pl
michal_paradowslu@imgw.pl
M. Champagne michele.champagne@meteo.fr
M. Steffenson mist@dmi.dk