Radars provide an impressive ability to remotely observe the internal motions in convective storms and infer precipitation types, as well as amounts. These instruments were evolving ever since it was first noticed that storms clutter radar displays meant to reveal enemy aircraft. Thus radar meteorology was born. Until the sixties only the return power from weather tracers was measured and it offered the first glimpses into precipitation structure hidden inside clouds. Possibilities opened up to recognize hail storms, tornadic signatures (i.e., hook echoes), the melting zone in stratiform precipitation, and even determine precipitation rates at the ground, albeit with considerable uncertainty. With the advent of Doppler radar kinematic features of storms could be observed and quantified. Furthermore, the addition of polarization diversity enables the user to infer types of precipitation and quantity amounts much more accurately than was previously possible.
The broad objectives in the radar information session are to expose the audience to the information about severe storms and precipitation, which can be provided by radars, and to exchange experiences in which radars play important role. Thus methods, observations, and interpretation of data from stormy or pre-stormy environments are appropriate topics. Tell tale signatures of kinematic phenomena in the fields of radial velocities, pertinent to both operational services and researchers, are subjects of special interest. On top of the list are tornado vortex signatures, mesocyclones, gust fronts initiated by storm outflows, and microbursts and downbursts that present hazards to aviation as well as human dwellings.
Currently these phenomena are routinely detected by automatic algorithms that operate on reflectivity and Doppler weather radar data. In addition to return power, these radars provide estimates of the wind toward the radar and its dispersion from which storm kinematics including shears and turbulence can be inferred. Use of two or more Doppler radars reveals the internal three dimensional wind structure in convective storms and their byproducts, all of which increase understanding of these fascinating phenomena leading to applications in aviation safety, hydrology, and detection of hazardous weather and its short term forecast. Indisputably, the Doppler weather radar has become the prime tool for observations, nowcasting, and study of severe local storms. Thus quantitative attributes, such as maximum wind speeds, divergence, updrafts and spatial and statistical distributions of these are of special interest.
Evolutionary changes occurring in radar applications include a) new frontiers in weather observations such as the utility of polarimetric measurements for discriminating and quantifying precipitation, b) reduction of errors and faster volume scans, c) spectral processing, d) developing algorithms, novel procedures, and methodologies for weather forecasting and warning, e) assimilation of radar data into NWP models, and f) gaining additional insights into weather phenomena.
There are at least three desirable features that can not be achieved by improving the present weather radar technology. These are: a) update of volume scans at intervals of 1 minute or less, b) observations near ground level over large areas, and c) the use of multipurpose radars to sample weather, control air traffic, and track non cooperative airplanes. The agile beam phased array technology can deal with issues a) and c) whereas a dense network of small, short wavelength radars is a contender to alleviate b).
We invite submissions on all the above aspects for inclusion in this session.