WSN05 – Toulouse 5-9 September, 2005

ACTIVITIES ON SHORT-RANGE ACTIVITIES ON SHORT-RANGE FORECASTING METHODS OF FOG, FORECASTING METHODS OF FOG,

VISIBILITY AND LOW CLOUDS IN EU COST VISIBILITY AND LOW CLOUDS IN EU COST ACTION 722ACTION 722

Silas Chr. Michaelides Silas Chr. Michaelides

Meteorological Service, Nicosia, CyprusMeteorological Service, Nicosia, Cyprus

WSN05 – Toulouse 5-9 September, 2005WSN05 – Toulouse 5-9 September, 2005

Cost Action 722 is a consortium of scientists Cost Action 722 is a consortium of scientists from twenty-two Institutions in fifteenfrom twenty-two Institutions in fifteen countries, countries,

coordinating their national research on coordinating their national research on forecasting methods of fog, visibility and low forecasting methods of fog, visibility and low

cloud.cloud.


Participating Institutions in Cost Action 722Participating Institutions in Cost Action 722Zentralanstalt für Meteorologie und Geodynamik Zentralanstalt für Meteorologie und Geodynamik

(Austria)(Austria)National Institute of Meteorology and Hydrology National Institute of Meteorology and Hydrology

(Bulgaria)(Bulgaria)Meteorological Service of Canada (Canada)Meteorological Service of Canada (Canada)

Cyprus Meteorological Service (Cyprus)Cyprus Meteorological Service (Cyprus)Danemarks Meteorologiske Institute (Denmark)Danemarks Meteorologiske Institute (Denmark)Finnish Meteorological Institute (FMI, Finland)Finnish Meteorological Institute (FMI, Finland)

Météo-France (France)Météo-France (France)


Deutscher Wetterdienst (DWD, Germany)Deutscher Wetterdienst (DWD, Germany)University of Marburg (Germany)University of Marburg (Germany)

University of Bonn (Germany)University of Bonn (Germany)Hungarian Meteorological Service (Hungary)Hungarian Meteorological Service (Hungary)Norwegian Meteorological Institute (Norway)Norwegian Meteorological Institute (Norway)

Institute of Meteorology and Water Management Institute of Meteorology and Water Management (Poland)(Poland)

Instituto Nacional de Meteorologia (INM, Spain)Instituto Nacional de Meteorologia (INM, Spain)


Sveriges Meteorologiska och Hydrologiska Sveriges Meteorologiska och Hydrologiska Institut (SMHI - Sweden)Institut (SMHI - Sweden)

Analysen & Konzepte (Switzerland)Analysen & Konzepte (Switzerland)University of Basel (Switzerland)University of Basel (Switzerland)

MeteoSwiss (Switzerland)MeteoSwiss (Switzerland)University of Leeds (United Kingdom)University of Leeds (United Kingdom)

University of Manchester, Institute of Science University of Manchester, Institute of Science and Technology (United Kingdom)and Technology (United Kingdom)U.K. Met. Office (United Kingdom)U.K. Met. Office (United Kingdom)


Official Web site: Official Web site: 137.248.191.94/137.248.191.94/costcost// WSN05 – Toulouse 5-9 September, 2005WSN05 – Toulouse 5-9 September, 2005

The main objective of the EU Cost The main objective of the EU Cost Action 722 is:Action 722 is:To develop advanced methods for To develop advanced methods for very short-range forecasts of fog, very short-range forecasts of fog, visibility and low clouds, adapted visibility and low clouds, adapted to characteristic areas and to user to characteristic areas and to user requirements. requirements.


•This overall objective includes:This overall objective includes: the development of pre-processed the development of pre-processed methods of the necessary input data, methods of the necessary input data, the development of the appropriate the development of the appropriate forecast models and methods and the forecast models and methods and the development of adaptable application development of adaptable application software for the production of the software for the production of the forecasts. forecasts.


The duration of the Action is The duration of the Action is five years and the effort has five years and the effort has been split into four Phases.been split into four Phases.


The major tasks during the First Phase were The major tasks during the First Phase were a) to a) to documentdocument the existing the existing forecast techniquesforecast techniques and and ongoing projectsongoing projects in the field of forecasting in the field of forecasting fog, visibility and low clouds within European fog, visibility and low clouds within European countries, and countries, and b) to b) to investigateinvestigate the needs by the needs by different groups of different groups of usersusers, based upon the evaluation of , based upon the evaluation of questionnaires filled out by customers and questionnaires filled out by customers and forecasters in many European countries.forecasters in many European countries.


The First Phase has been Completed and the results have been publishedThe First Phase has been Completed and the results have been published


The second Phase The second Phase ((Research and Research and

DevelopmentDevelopment) is in its final ) is in its final year of completion and the year of completion and the

threethree broad broad research areasresearch areas: : WSN05 – Toulouse 5-9 September, 2005WSN05 – Toulouse 5-9 September, 2005

11stst)) initial datainitial data acquisition, acquisition, techniques and requirements, techniques and requirements, 22ndnd)) initialization of initialization of modelsmodels and and testing of the microphysics of testing of the microphysics of different models, different models, 33rdrd)) the development and the development and testing of testing of statistical methodsstatistical methods..


The aim of the Third Phase (Development and The aim of the Third Phase (Development and Application) is to ensure that the methods can Application) is to ensure that the methods can be used at different Institutes. During the last be used at different Institutes. During the last Fourth Phase (Dissemination) the results and Fourth Phase (Dissemination) the results and

methods will be distributed.methods will be distributed.


In the following, a brief review is made In the following, a brief review is made of of somesome of the of the taskstasks undertaken under undertaken under different research areas of the current different research areas of the current second Phase in order to display the second Phase in order to display the spectrum spectrum of the research efforts in of the research efforts in

Cost 722Cost 722


11stst Research Area: INITIAL DATA Research Area: INITIAL DATA

The objective of this research area is to The objective of this research area is to use use satellite datasatellite data and and in-situin-situ

measurements for the derivation of a measurements for the derivation of a climatologyclimatology of visibility, fog and low stratus of visibility, fog and low stratus and for a better understanding of relevant and for a better understanding of relevant

processes for the formation and dissipation processes for the formation and dissipation of fog and low stratus.of fog and low stratus.


The two main activities under this research The two main activities under this research area are:area are:

The climatology of fogThe climatology of fog, and, and

the detection and determination of fog the detection and determination of fog propertiesproperties


Climatology of fogClimatology of fog


The Instituto Nacional de Meteorologia The Instituto Nacional de Meteorologia (INM), reports on the development of a (INM), reports on the development of a conceptual model for fog forecasting in conceptual model for fog forecasting in

Central Spain.Central Spain.


Climatology of fogClimatology of fog: Instituto Nacional de Meteorologia (INM): Instituto Nacional de Meteorologia (INM)


Through a systematic subjective mesoscale analysis, the coexistence of two mesoscale mechanisms in most of fog events has been shown: cold drainage winds converging at the bottom of the valleys and a warm advection of air from the Mediterranean or the Atlantic


Under these circumstances, nights with clear skies, katabatics winds are overflown by warm air.


150 Km

1,5 Km



Methodology for fog forecasting is based on a combination of Teledetection (using Meteosat channel 6, centered at 7.3 m), and Numerical Weather Pediction (single-column version of HIRLAM)


WV image HIRLAM 00+06T and Wind 850 hPa

In the Finnish In the Finnish Meteorological Institute, Meteorological Institute,

work is in progress, work is in progress, regarding the development regarding the development of climatological forecasting of climatological forecasting

tools. tools. WSN05 – Toulouse 5-9 September, 2005WSN05 – Toulouse 5-9 September, 2005

Climatology of fogClimatology of fog:: Finnish Meteorological Institute (FMI)Finnish Meteorological Institute (FMI)

30 years of 30 years of SYNOPSYNOP observations for selected observations for selected stationsstations

Observations should be classified in groups of Observations should be classified in groups of typical low visibility situationstypical low visibility situations

It would help forecasters to learn the It would help forecasters to learn the climatologies of new areas they are assigned to. climatologies of new areas they are assigned to.

It might even show new dependencies, not It might even show new dependencies, not thought of before. thought of before.

Clustering algorithms can do this.Clustering algorithms can do this.



Clustering of fog “situations”Clustering of fog “situations”



Example:An Example:An advection fog clusteradvection fog cluster using NCEP using NCEP data. data. Mean Mean and the and the standard deviationstandard deviation

of geopotential and temperatureof geopotential and temperature



The Institute of Meteorology and The Institute of Meteorology and Water Management of Poland (IMGW) Water Management of Poland (IMGW)

developed a climatology on small-developed a climatology on small-scale advection for Warsaw and scale advection for Warsaw and

Krakow Airports based upon 30 years Krakow Airports based upon 30 years of synoptic data.of synoptic data.


Climatology of fogClimatology of fog:: Institute of Meteorology and Water Management of Poland (IMGW)Institute of Meteorology and Water Management of Poland (IMGW)


Weather patterns preceding the fog

development. Warsow

Type 1, 10%

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• a low to the north-west or north of Poland• advection directions: SW or W• late autumn and winter • cloudy sky in all cases with precipitation • a west wind, 1 - 3 mps• advection and precipitation fogs

Representation of a cluster of conditions favorable for fog formation

Climatology of fogClimatology of fog:: Institute of Meteorology and Water Management of Poland (IMGW)Institute of Meteorology and Water Management of Poland (IMGW)

The Bulgarian National Institute of The Bulgarian National Institute of Meteorology and Hydrology works on Meteorology and Hydrology works on

fog climatologyfog climatology

By using multiple linear regression (data By using multiple linear regression (data sequences with a length of 92 terms), statistical sequences with a length of 92 terms), statistical

relationships between visibility and several relationships between visibility and several predictors were establishedpredictors were established


Climatology of fogClimatology of fog:: Bulgarian National Institute of Meteorology and HydrologyBulgarian National Institute of Meteorology and Hydrology

Several parameters have been examined: Several parameters have been examined: relative humidity, temperature, wind relative humidity, temperature, wind

direction and speed, at four levels at Sofia direction and speed, at four levels at Sofia station, 700, 850, 925hPa, and ground station, 700, 850, 925hPa, and ground

level together with SYNOP data for several level together with SYNOP data for several stations in Bulgariastations in Bulgaria



Encouraged by the results of this study, Aladin and Encouraged by the results of this study, Aladin and HRM are employed to obtain visibility values in the HRM are employed to obtain visibility values in the

beginning and in the end of the fog formationbeginning and in the end of the fog formation



Normal Probability Plot of Residuals

-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2

Residuals

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Detection and Detection and determination of fog determination of fog

propertiesproperties


In the Finnish Meteorological Institute, In the Finnish Meteorological Institute, tests were carried out with the tests were carried out with the wind profiler wind profiler

LAP3000LAP3000 (Vaisala) at Rovaniemi Airport. (Vaisala) at Rovaniemi Airport. This instrument showed a good This instrument showed a good

performance during situations with fog and performance during situations with fog and low stratus.low stratus.


Detection and determination of fog propertiesDetection and determination of fog properties :: Finnish Meteorological Institute (FMI)Finnish Meteorological Institute (FMI)

In Météo-France, work is progress to In Météo-France, work is progress to review the potentials and shortcomings of review the potentials and shortcomings of

different different LIDARLIDAR and and SODARSODAR instruments. Both instruments. Both methods are good for fog, however, LIDAR methods are good for fog, however, LIDAR

cannot penetrate dense fog and SODAR hardly cannot penetrate dense fog and SODAR hardly detects thin fog layers. Heavy air traffic causes detects thin fog layers. Heavy air traffic causes

problems which limits the use at airports. problems which limits the use at airports.


Detection and determination of fog propertiesDetection and determination of fog properties :: Météo-FranceMétéo-France

At the University of Marburg, At the University of Marburg, Germany, research is done Germany, research is done on the retrieval of fog areas on the retrieval of fog areas and properties from satellite and properties from satellite

imagery. imagery. WSN05 – Toulouse 5-9 September, 2005WSN05 – Toulouse 5-9 September, 2005

Detection and determination of fog propertiesDetection and determination of fog properties :: University of Marburg, GermanyUniversity of Marburg, Germany

Using parameterizations Using parameterizations based on radiative transfer based on radiative transfer and microphysics, fog and and microphysics, fog and

low stratus can be low stratus can be separated with some degree separated with some degree

of certainty. of certainty. WSN05 – Toulouse 5-9 September, 2005WSN05 – Toulouse 5-9 September, 2005

Detection and determination of fog propertiesDetection and determination of fog properties :: University of Marburg, GermanyUniversity of Marburg, Germany

22ndnd Research Area: Research Area: MODELSMODELSThe main activities under this The main activities under this

research area are: research area are: the initialization of models,the initialization of models,

the investigation of microphysics,the investigation of microphysics, the development and testingthe development and testing of of

modelsmodels


In University of Basle Switzerland, by In University of Basle Switzerland, by using the NCEP (National Centers for using the NCEP (National Centers for

Environment Prediction) model (1km), it Environment Prediction) model (1km), it was found that topography is important for was found that topography is important for forecasting fog and low clouds. First trials forecasting fog and low clouds. First trials of of ensemble forecastingensemble forecasting are in progress by are in progress by

varying the initial conditions slightly.varying the initial conditions slightly.


Initialization of modelsInitialization of models:: University of Basle, Switzerland

A fog and low stratus forecast system was developed for Zurich Unique airport

in Switzerland. Fog prediction is done using an ensemble of 1D

forecasts. Necessary initial conditions are obtained from

variational data assimilation.


Initialization of modelsInitialization of models:: University of Basle, Switzerland

Investigation of Investigation of microphysicsmicrophysics


In order to improve the understanding of In order to improve the understanding of the the microphysical processesmicrophysical processes within the clouds within the clouds

and to get a better understanding of the and to get a better understanding of the phenomenon “fog”, phenomenon “fog”, several measurement several measurement

campaignscampaigns (field and aircraft) are planned for (field and aircraft) are planned for winter 2005/2006 (Finland, Toronto, New York winter 2005/2006 (Finland, Toronto, New York Airport). These experiments will also serve to Airport). These experiments will also serve to

inter-compare ground-based fog property inter-compare ground-based fog property measurements with satellite retrievals.measurements with satellite retrievals.


Investigation of Microphysics Investigation of Microphysics :: Finnish Meteorological Institute and Met. Service of Canada

Development and testing Development and testing of modelsof models


Development and testing of modelsDevelopment and testing of models

Physical processesPhysical processes involved in the involved in the formation of fog interact in a complex and formation of fog interact in a complex and

highly non-linear manner.highly non-linear manner. Such interactions are not resolved by Such interactions are not resolved by

operational mesoscale models.operational mesoscale models. Therefore, the development of a 3-D fog Therefore, the development of a 3-D fog

forecasting model calls for a finer forecasting model calls for a finer horizontal and vertical resolution.horizontal and vertical resolution.



For the development and testing For the development and testing of models in forecasting low of models in forecasting low

visibilities and low cloud, visibilities and low cloud, several models are under several models are under examination by various examination by various

Institutions within Cost 722.Institutions within Cost 722.



The University of Bonn works on the The University of Bonn works on the development of a nested 50km 3-D-version of development of a nested 50km 3-D-version of the LM (Lokal modell of DWD) with a very fine the LM (Lokal modell of DWD) with a very fine

vertical resolution near the surface, at 2, 6, 10 m vertical resolution near the surface, at 2, 6, 10 m from the ground. The parameterizations are from the ground. The parameterizations are

taken from the parameterized fog microphysics taken from the parameterized fog microphysics model – PAFOGmodel – PAFOG


Development and testing of modelsDevelopment and testing of models :: University of Bonn, Germany


NMM_PAFOG

PAFOG is also used in another modeling approach PAFOG is also used in another modeling approach which involves the Universities of Bonn and Basle. In which involves the Universities of Bonn and Basle. In this approach, the this approach, the NOAA/NCEP Nonhydrostatic NOAA/NCEP Nonhydrostatic Mesoscale Model (NMM)Mesoscale Model (NMM) is coupled with PAFOG. is coupled with PAFOG.

NMM-4 NMM_PAFOG

Development and testing of modelsDevelopment and testing of models :: Universities of Bonn, Germany and Basle, Switzerland

The representation of low The representation of low cloudiness (Stratus) with the Aladin cloudiness (Stratus) with the Aladin model is studied in Zentralanstalt für model is studied in Zentralanstalt für

Meteorologie und Geodynamik Meteorologie und Geodynamik (Austria) by extending their system:(Austria) by extending their system:

Integrated Nowcasting through Integrated Nowcasting through Comprehensive Analysis (INCA)Comprehensive Analysis (INCA)


Development and testing of modelsDevelopment and testing of models :: Zentralanstalt für Meteorologie und Geodynamik, AustriaZentralanstalt für Meteorologie und Geodynamik, Austria

The HIRLAM 1-D model (initialized with 3-D) is tested The HIRLAM 1-D model (initialized with 3-D) is tested in the Sveriges Meteorologiska och Hydrologiska in the Sveriges Meteorologiska och Hydrologiska

Institut (SMHI).Institut (SMHI).


Development and testing of modelsDevelopment and testing of models :: Sveriges Meteorologiska och Hydrologiska Institut (SMHI)Sveriges Meteorologiska och Hydrologiska Institut (SMHI)

A numerical forecast method integrating dedicated A numerical forecast method integrating dedicated observations and the COBEL-ISBA high resolution numerical observations and the COBEL-ISBA high resolution numerical

model has been developed in Météo-France.model has been developed in Météo-France.


Local Assimilation Local Assimilation SchemeScheme

ObservationsObservations ISBA ISBA ““offlineoffline””

COBEL/ISBACOBEL/ISBA

fog and low clouds forecastingfog and low clouds forecasting

Adjustment Adjustment requirements / forecastrequirements / forecast

guess

Mesoscale NWP Mesoscale NWP model (3D)model (3D)

Improved site-specific numerical prediction

Development and testing of modelsDevelopment and testing of models :: Météo-FranceMétéo-France

Experience with the modelling approach shows:

Promising first results

Computationally very efficient and feasible in todays operational framework

However, more cases and ‘verification’ needed


Model IntercomparisonModel IntercomparisonWithin Cost 722, one very important Within Cost 722, one very important

component of the effort for the component of the effort for the development and testing of models is the development and testing of models is the

model inter-comparison. model inter-comparison.


Participating InstitutionParticipating InstitutionUniversity of BonnUniversity of Bonn

Analysen & KonzepteAnalysen & KonzepteUniversity of BaselUniversity of Basel

Instituto Nacional de MeteorologiaInstituto Nacional de Meteorologia


This task is currently under deployment but This task is currently under deployment but some preliminary results are already available some preliminary results are already available for for LindenbergLindenberg in Germany (where three 1-D in Germany (where three 1-D models are tested on common fog periods)models are tested on common fog periods)

11stst Model Intercomparison Model Intercomparison

One more inter-comparison task is also under One more inter-comparison task is also under deployment in France for deployment in France for CDG AirportCDG Airport..

ParticipatingParticipating InstitutionInstitutionInstituto Nacional de MeteorologiaInstituto Nacional de Meteorologia

Analysen & KonzepteAnalysen & KonzepteDanemarks Meteorologiske InstituteDanemarks Meteorologiske Institute

Météo-FranceMétéo-FranceUniversity of BaselUniversity of Basel

Univ. de les Illes BalearsUniv. de les Illes Balears


22ndnd Model Intercomparison Model Intercomparison


3rd Research Area: 3rd Research Area: STATISTICAL METHODSThe following two issues are considered in this research area:a. Improvement and innovation (statisticaldeterministic and probabilistic forecasting of visibility, fog and low clouds are investigated)b. Selection of Predictors and evaluationof methods (The most important parameters for high quality forecasts are to be selected)

Improvement and Improvement and innovation of statistical innovation of statistical

forecastingforecasting


The Norwegian Met. Service The Norwegian Met. Service and the Cyprus Met. Serviceand the Cyprus Met. Serviceco-operate in developing an co-operate in developing an

Artificial Neural NetworkArtificial Neural Networkforecasting sytem for Larnaca forecasting sytem for Larnaca

Airport in CyprusAirport in Cyprus


Improvement and innovationImprovement and innovation :: Norwegian Met. Service – Cyprus Met. Service

List of predictors used for forecasting List of predictors used for forecasting Meteorological Optical Range (predictand).Meteorological Optical Range (predictand).

MonthMonthHourHour

Visibility (MOR)Visibility (MOR)Height of cloud base (HCB)Height of cloud base (HCB)

Wind speedWind speedWind directionWind directionTemperature Temperature

Dew point temperatureDew point temperatureRelative humidityRelative humidity

PressurePressure



Data: From Automatic Weather Observing SystemData: From Automatic Weather Observing System

Graphical presentation of probabilistic forecasts.Graphical presentation of probabilistic forecasts.



Hungarian Met. Service – Hungarian Met. Service – Cyprus Met. ServiceCyprus Met. Service co-operate co-operate in comparing different visibility in comparing different visibility forecast methods for Larnaca forecast methods for Larnaca

Airport- CyprusAirport- Cyprus


Improvement and innovationImprovement and innovation :: Hungarian Met. Service – Cyprus Met. Service

Three methods were tested:Three methods were tested:

1. Artificial Neural Network 1. Artificial Neural Network 2. Genetic alghorithm. 2. Genetic alghorithm.3. Decision tree (Hungarian).3. Decision tree (Hungarian).

Data:Data: From Automatic Weather From Automatic Weather Observing System and ECMWFObserving System and ECMWF





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Observed vis.

Genetic. vis

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15-hour visibility forecast by using ECMWF forecast

1-7 March 2003 – Larnaca Airport

Selection of predictors Selection of predictors and evaluation of methodsand evaluation of methods


Météo-France proposed a method for Météo-France proposed a method for determining how to evaluate the potential determining how to evaluate the potential

of existing methods.of existing methods.

The proposed methodology can be applied to any forecasting method, The proposed methodology can be applied to any forecasting method,

statistical or based on numerical modellingstatistical or based on numerical modelling


Selection of predictors and evaluationSelection of predictors and evaluation :: Météo-France



Pseudo-ROC diagram (which shows Hit Rate versus False Alarm Ratio, Pseudo-ROC diagram (which shows Hit Rate versus False Alarm Ratio, the bias of deterministic forecasts and the ability of probabilistic forecasts the bias of deterministic forecasts and the ability of probabilistic forecasts to discriminate between events and non-events)to discriminate between events and non-events)

First aspect: detection First aspect: detection and false alarmsand false alarms



Reliability diagram (which shows observed frequency versus forecast Reliability diagram (which shows observed frequency versus forecast probability and the probability bias of probabilistic forecasts).probability and the probability bias of probabilistic forecasts).

Second aspect: reliability Second aspect: reliability (of prob forecasts)(of prob forecasts)

In MeteoSwiss, work is under way for In MeteoSwiss, work is under way for defining a methodology for the selection of defining a methodology for the selection of predictors in statistical forecasting of fog predictors in statistical forecasting of fog

and low visibilities.and low visibilities.

Two methodologies are under Two methodologies are under consideration:consideration:


Selection of predictors and evaluationSelection of predictors and evaluation :: MeteoSwiss



a) The variables are selected before the multivariate model is set up



b) The selection of variables is included in the whole modeling process

This presentation was just an This presentation was just an overviewoverview of of the activities in Cost 722 showing the the activities in Cost 722 showing the widewide spectrumspectrum of tasks undertaken by several of tasks undertaken by several

researchers.researchers.Conclusion:Conclusion: Experience has shown that Experience has shown that developing forecasting methods for such developing forecasting methods for such complexcomplex phenomena such those of low phenomena such those of low visibilities, fog and Stratus requires an visibilities, fog and Stratus requires an

extensive extensive multi-disciplinarymulti-disciplinary cooperation. cooperation.


Thank youThank you


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WSN05 – Toulouse 5-9 September, 2005