How to Draw a Circular Arrows Diagram Using ConceptDraw PRO

This work flow chart sample was redesigned from the picture "Weather Forecast" from the article "Simulation Workflows".
[iaas.uni-stuttgart.de/ forschung/ projects/ simtech/ sim-workflows.php]
"(1) The weather is predicted for a particular geological area. Hence, the workflow is fed with a model of the geophysical environment of ground, air and water for a requested area.
(2) Over a specified period of time (e.g. 6 hours) several different variables are measured and observed. Ground stations, ships, airplanes, weather balloons, satellites and buoys measure the air pressure, air/ water temperature, wind velocity, air humidity, vertical temperature profiles, cloud velocity, rain fall, and more.
(3) This data needs to be collected from the different sources and stored for later access.
(4) The collected data is analyzed and transformed into a common format (e.g. Fahrenheit to Celsius scale). The normalized values are used to create the current state of the atmosphere.
(5) Then, a numerical weather forecast is made based on mathematical-physical models (e.g. GFS - Global Forecast System, UKMO - United Kingdom MOdel, GME - global model of Deutscher Wetterdienst). The environmental area needs to be discretized beforehand using grid cells. The physical parameters measured in Step 2 are exposed in 3D space as timely function. This leads to a system of partial differential equations reflecting the physical relations that is solved numerically.
(6) The results of the numerical models are complemented with a statistical interpretation (e.g. with MOS - Model-Output-Statistics). That means the forecast result of the numerical models is compared to statistical weather data. Known forecast failures are corrected.
(7) The numerical post-processing is done with DMO (Direct Model Output): the numerical results are interpolated for specific geological locations.
(8) Additionally, a statistical post-processing step removes failures of measuring devices (e.g. using KALMAN filters).
(9) The statistical interpretation and the numerical results are then observed and interpreted by meteorologists based on their subjective experiences.
(10) Finally, the weather forecast is visualized and presented to interested people." [iaas.uni-stuttgart.de/ forschung/ projects/ simtech/ sim-workflows.php]
The example "Workflow diagram - Weather forecast" was drawn using the ConceptDraw PRO diagramming and vector drawing software extended with the Workflow Diagrams solution from the Business Processes area of ConceptDraw Solution Park.