The Use of Digital Radar in Short-range Forecasting

The Use of Digital Radar in Short-range Forecasting PDF

Author: H. Stuart Muench

Publisher:

Published: 1976

Total Pages: 64

ISBN-13:

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As part of a program to improve short-range forecasts of weather conditions at aircraft terminals, a digital radar system was established at Air Force Geophysics Laboratory, Bedford Mass. The system, consisting of AN/FPS-77, digital interface, microwave transmitter-receiver, video integrator and computer, was installed in late 1972. Since that time the system has been used in conjunction with a network of 26 automated weather stations to make experimental forecasts of visibility and severe-weather conditions. The radar output of digital maps of radar intensity was found to be very convenient, but the inability of the radar to detect small water droplets limits the use in low visibility forecasting primarily to heavy rain storms and snow storms. In severe storms modest success was attained forecasting gusts, using digital maps. The large amounts of weather information from the network and radar frequently saturated the forecaster making forecasts at 15-min intervals, and relief was sought in the form of objective aids. Preliminary relationships between radar intensity, extinction coefficient (visibility) and rainfall rate have been formulated. In addition, a technique was developed using digital radar maps to obtain motion vectors and make probability forecasts of severe weather conditions. The calibration procedure relies on intensity of ground targets (hills and towers) for day-to-day relative calibration, and absolute calibration has been limited to Z-R relations. (Author).

The Use of Digital Radar in Short-range Forecasting

The Use of Digital Radar in Short-range Forecasting PDF

Author: H. Stuart Muench

Publisher:

Published: 1976

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK →

As part of a program to improve short-range forecasts of weather conditions at aircraft terminals, a digital radar system was established at Air Force Geophysics Laboratory, Bedford Mass. The system, consisting of AN/FPS-77, digital interface, microwave transmitter-receiver, video integrator and computer, was installed in late 1972. Since that time the system has been used in conjunction with a network of 26 automated weather stations to make experimental forecasts of visibility and severe-weather conditions. The radar output of digital maps of radar intensity was found to be very convenient, but the inability of the radar to detect small water droplets limits the use in low visibility forecasting primarily to heavy rain storms and snow storms. In severe storms modest success was attained forecasting gusts, using digital maps. The large amounts of weather information from the network and radar frequently saturated the forecaster making forecasts at 15-min intervals, and relief was sought in the form of objective aids. Preliminary relationships between radar intensity, extinction coefficient (visibility) and rainfall rate have been formulated. In addition, a technique was developed using digital radar maps to obtain motion vectors and make probability forecasts of severe weather conditions. The calibration procedure relies on intensity of ground targets (hills and towers) for day-to-day relative calibration, and absolute calibration has been limited to Z-R relations. (Author)

Weather Radar Technology Beyond NEXRAD

Weather Radar Technology Beyond NEXRAD PDF

Author: National Research Council

Publisher: National Academies Press

Published: 2002-08-31

Total Pages: 181

ISBN-13: 0309084660

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Weather radar is a vital instrument for observing the atmosphere to help provide weather forecasts and issue weather warnings to the public. The current Next Generation Weather Radar (NEXRAD) system provides Doppler radar coverage to most regions of the United States (NRC, 1995). This network was designed in the mid 1980s and deployed in the 1990s as part of the National Weather Service (NWS) modernization (NRC, 1999). Since the initial design phase of the NEXRAD program, considerable advances have been made in radar technologies and in the use of weather radar for monitoring and prediction. The development of new technologies provides the motivation for appraising the status of the current weather radar system and identifying the most promising approaches for the development of its eventual replacement. The charge to the committee was to determine the state of knowledge regarding ground-based weather surveillance radar technology and identify the most promising approaches for the design of the replacement for the present Doppler Weather Radar. This report presents a first look at potential approaches for future upgrades to or replacements of the current weather radar system. The need, and schedule, for replacing the current system has not been established, but the committee used the briefings and deliberations to assess how the current system satisfies the current and emerging needs of the operational and research communities and identified potential system upgrades for providing improved weather forecasts and warnings. The time scale for any total replacement of the system (20- to 30-year time horizon) precluded detailed investigation of the designs and cost structures associated with any new weather radar system. The committee instead noted technologies that could provide improvements over the capabilities of the evolving NEXRAD system and recommends more detailed investigation and evaluation of several of these technologies. In the course of its deliberations, the committee developed a sense that the processes by which the eventual replacement radar system is developed and deployed could be as significant as the specific technologies adopted. Consequently, some of the committee's recommendations deal with such procedural issues.

Hydrometeorology

Hydrometeorology PDF

Author: Christopher G. Collier

Publisher: John Wiley & Sons

Published: 2016-08-08

Total Pages: 406

ISBN-13: 1118414977

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Hydrometeorology presents an introduction to relevant topics in the interdisciplinary fields of hydrology and meteorology. This book is one of the few books aiming to provide a balance between aspects of meteorological and hydrological processes. The transfer of energy and water between the land surface and lower atmosphere within the hydrological cycle is addressed followed by a description of the nature of precipitation, and how it is formed. Forecasting precipitation is reviewed on all scales, and the range of rainfall-runoff models and coastal surge models and forecasts (including tsunamis) which have been, and are being, used are discussed. The mechanisms of snow, ice (glacier, sea and tundra), evaporation and transpiration, how drought occurs and the representation of wind are described. How rainfall (including radar measurements) and river flow information is gathered and analysed (including, frequency analysis, Probable Maximum Precipitation and Flood) are presented. Satellite measurements of precipitation are discussed. Examples of major past floods and droughts are given. Past and future climate change, which is included, underpins the importance of hydro-meteorological processes. The structure of the general circulation of the atmosphere and how it influences weather and climate including the Hadley, Ferrel and Polar cells, the Trade winds and the El Nino, is outlined. Finally, the influence of urban areas on rainfall formation, dealing with urban drainage and air quality are described. Each chapter ends with one or two specific points as appendices, elements discussed in the chapter and a list of sample problems to aid understanding. Readership: This book is aimed at 3rd year undergraduate and postgraduate students on hydrology/hydrometeorology, environmental science and geography courses. Professionals in environmental protection agencies and consultancies will also find the book of great interest. It contains a balance of both the physics and mathematics which underpin such courses and activities.

International Weather Radar Networking

International Weather Radar Networking PDF

Author: C.G. Collier

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 323

ISBN-13: 9401124043

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International Weather Radar Networking covers all aspects of the subject in a collection of contributions drawn from all over the world. Of particular interest are the papers describing work in Eastern Europe and papers reviewing of the achievements of the Commission of the European Communities COST-73 project. During the last twenty years there has been a rapid growth in the number of digital radars deployed for operational use in Western Europe. There are now around 100, of which about half have a Doppler capability, providing wind as well as reflectivity information. The international exchange of the data from these systems promises a great enhancement of the benefits to weather forecasting and commercial users. This volume reports work being undertaken to realize those benefits and points the way to future developments of radar technology.

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