Short Term Forecasting of Cloud and Precipitation
Short Term Forecasting of Cloud and Precipitation

Author: Alan R. Bohne

Publisher:

Published: 1988

Total Pages: 106

ISBN-13:

DOWNLOAD EBOOK

A methodology for real-time operations has been developed for the short-term forecasting of cloud and precipitation fields. Pattern recognition techniques are employed to extract useful features from the data field and extrapolation techniques are used to project these features into the future. To reduce computational load, contours defined by directional codes are used to delineate features. These contours are subdivided and attributes such as length, location, and location of each segment are determined. Segment matching is performed for successive observations and attribute changes are monitored over time. Several techniques for the forecasting of attributes have been explored, and an exponential smoothing filter and a linear trend adaptive smoothing filter have been chosen as most appropriate. Currently analysis is performed on a minicomputer and image processor system utilizing radar reflectivity data. Refinement of these techniques and extension into a more comprehensive short term forecasting program is planned.

Short Term Forecasting of Cloud and Precipitation Along Communication Paths
Short Term Forecasting of Cloud and Precipitation Along Communication Paths

Author: Alan R. Bohne

Publisher:

Published: 1985

Total Pages: 34

ISBN-13:

DOWNLOAD EBOOK

A methodology for real-time operations has been developed for the short-term forecasting of cloud and precipitation fields. Pattern recognition techniques are employed to extract useful features from the data field and extrapolation techniques are used to project these features into the future. To reduce computational load, contours defined by directional codes are used to delineate features. These contours are subdivided and attributes such as length, location, and location of each segment are determined. Segment matching is performed for successive observations and attribute changes are monitored over time. Several techniques for the forecasting of attributes have been explored, and an exponential smoothing filter and a linear trend adaptive smoothing filter have been chosen as most appropriate. Currently analysis is performed on a minicomputer and image processor system utilizing radar reflectivity data. Refinement of these techniques and extension into a more comprehensive short term forecasting program is planned. Keywords: Now casting, Pattern recognition, Extrapolation, Forecasting, Radar, Data filtering, Contour, Segmentation. (SDW)

Short Term Forecasting of Cloud and Precipitation
Short Term Forecasting of Cloud and Precipitation

Author: A. Bohne

Publisher:

Published: 1988

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

A methodology for real-time operations has been developed for the short-term forecasting of cloud and precipitation fields. Pattern recognition techniques are employed to extract useful features from the data field and extrapolation techniques are used to project these features into the future. To reduce computational load, contours defined by directional codes are used to delineate features. These contours are subdivided and attributes such as length, location, and location of each segment are determined. Segment matching is performed for successive observations and attribute changes are monitored over time. Several techniques for the forecasting of attributes have been explored, and an exponential smoothing filter and a linear trend adaptive smoothing filter have been chosen as most appropriate. Currently analysis is performed on a minicomputer and image processor system utilizing radar reflectivity data. Refinement of these techniques and extension into a more comprehensive short term forecasting program is planned.

Short-range Forecasting of Cloudiness and Precipitation Through Extrapolation of GOES Imagery
Short-range Forecasting of Cloudiness and Precipitation Through Extrapolation of GOES Imagery

Author: H. Stuart Muench

Publisher:

Published: 1981

Total Pages: 50

ISBN-13:

DOWNLOAD EBOOK

This report describes the development and testing of an objective technique to forecast cloudiness and precipitation through extrapolation of satellite imagery. By utilizing on objectively determined cloud-motion vector, the technique makes local forecasts of satellite parameters (brightness and IR temperature), with high temporal resolution, using simple linear extrapolation. Algorithms are then used to convert the satellite parameters to total cloud cover, probability of 1-hour precipitation, and presence of low, middle, and high clouds. The test program computed motion vectors and made forecasts out to 7 hours, in half-hour steps, at 30 locations. The program was tested on 12 spring and fall cases, using half-hourly GOES imagery. For periods beyond 2 hours, forecasts of cloud cover and precipitation were markedly better than persistence, which deficiencies in specification hindered short-period performance. Forecasts of cloud layers were worse than persistence due to inadequate specification algorithms. The net results were quite encouraging, and further refinements and developments are planned.

Some Techniques for Short-range Terminal Forecasting
Some Techniques for Short-range Terminal Forecasting

Author: Clay G. Russell

Publisher:

Published: 1970

Total Pages: 56

ISBN-13:

DOWNLOAD EBOOK

The report describes several techniques applicable to short-range terminal forecasting. Areas discussed are procedures for graphical extrapolation, nephanalysis, forecasting frontal precipitation, and the lowering of ceilings during precipitation. The use of FPS-77 rada and weather satellite data is shown as they pertain to short-range forecasting. (Author).

Some Problems in the Theory of the Formation of Clouds and Precipitation
Some Problems in the Theory of the Formation of Clouds and Precipitation

Author: Nikolaĭ Sergeevich Shishkin

Publisher:

Published: 1968

Total Pages: 20

ISBN-13:

DOWNLOAD EBOOK

Research on clouds and precipitation has undergone considerable development in the Soviet Union during the last forty years. In the pre-war years, a great deal of data was collected from the network of weather stations on clouds and precipitation; synoptic methods of forecasting these phenomena were developed; a substantial amount of laboratory research was carried out on thunderstorm electricity and the mechanism of precipitation formation; and research was begun on clouds in the vicinity of mountains. Immediately after the war, research was renewed in the Soviet Union on the active modification of clouds and fog. Physical methods have been developed for forecasting cloudiness and precipitation, based on the solution to dynamic atmosphere equations and energy relationships. In recent years, more and more effort has been put into cloud research and into the development of methods of active modification.

Aviation Meteorology: Observations and Models
Aviation Meteorology: Observations and Models

Author: Ismail Gultepe

Publisher: Birkhäuser

Published: 2019-11-11

Total Pages: 0

ISBN-13: 9783030309817

DOWNLOAD EBOOK

This Topical Volume focuses on aviation meteorology for operations and research, covering important topics related to wind and turbulence, visibility, fog and precipitation, convection and lightning, icing, blowing snow, and ice cloud microphysics and dynamics. In addition to forecasting issues, the impact of climate on aviation operations is also highlighted, as temperature and moisture changes can affect aircraft aerodynamic conditions, such as lift and drag forces. This work uses measurements from state of art in-situ instruments and simulation results from numerical weather prediction (NWP) and climate models. New technologies related to satellites, radars, lidars, and UAVs (Unmanned Aerial Vehicles) are described, as well as new analysis methods related to artificial intelligence (AI) and neural network systems. Use of remote sensing platforms, including satellites, radars, radiometers, ceilometers, sodars, and lidars, as well as knowledge of the in-situ observations for the monitoring and short-term forecasting of wind, turbulence, gust, clear air turbulence (CAT), low visibility due to fog and clouds, and precipitation types are required for aviation operations at the airports and high level flying conditions. This book provides extensive knowledge for aviation-related meteorological processes and events that include short and long term prediction of high impact weather systems. Aviation experts, weather offices, pilots, university students, postgraduates, and researchers interested in aviation and meteorology, including new instruments for measurements applicable to forecasting and nowcasting, can benefit from consulting and reading this book. This book provides a comprehensive overview of our existing knowledge and the numerous remaining difficulties in predicting and measuring issues related to wind and turbulence, convection, fog and visibility, various cloud types, icing, and ice clouds at various time and space scales. Previously published in Pure and Applied Geophysics, Volume 176, Issue 5, 2019

Very Short Range Statistical Forecasting of Automated Weather Observations
Very Short Range Statistical Forecasting of Automated Weather Observations

Author: Robert G. Miller

Publisher:

Published: 1984

Total Pages: 24

ISBN-13:

DOWNLOAD EBOOK

A procedure is developed for providing weather forecasting guidance over the short period between 1 to 60 minutes. It uses automated surface observation elements as predictors and predictands. The same equations project probabilistic predictions iteratively minute-by-minute. The model is founded on a Markov assumption and utilizes multivariate linear regression as the statistical operator. Details are given on how the model is constructed and how it compares with other objective methods such as climatology and persistence. Tests are performed on a new nonlinear approach.