Doppler Weather Radar Research and Development
NSSL Project 8 – Investigation into the use of Phased Array Radar Technology for Improving Hazardous Weather Detection and Warnings:
Rapid Sampling of Storms
Funding Type: CIMMS Task II
Objectives
Demonstrate the phased array radar’s ability to collect rapid-scan
volumetric data that provide more detailed depictions of quickly-evolving
severe storm structures (e.g., microburst precursors) than the WSR-88D
and TDWR.
Accomplishments
A key advantage of the National Weather Radar Testbed Phased Array Radar
(PAR) is the capability to adaptively scan storms at higher temporal
resolution than is possible with the Weather Surveillance Radar-1988
Doppler (WSR-88D; 1 min or less vs. 4.1 min, respectively). High-temporal
resolution volumetric radar data is a necessity for rapid identification
and confirmation of weather phenomena that can develop within minutes.
The purpose of this research is to demonstrate the PAR’s ability
to collect rapid-scan volumetric data that provide more detailed depictions
of quickly evolving storm structures than the WSR-88D and TDWR (for
microbursts only).
Advantages of higher-temporal resolution PAR data are examined for three convective storms that occurred during the spring and summer of 2006, including a re-intensifying supercell, a microburst, and a hail storm. The analysis of the re-intensifying supercell (58 s updates) illustrates the opportunity to more quickly identify and confirm developing and/or intensifying areas of 1) low-altitude divergence and rotation and 2) rotation through the depth of the storm. The fuller sampling of the microburst’s storm life cycle (34 s updates) depicts precursors to the strong surface outflow that are essentially indiscernible in the WSR-88D data. Furthermore, the 34 s scans provide a more precise sampling of peak outflow. The more frequent sampling of the hail storm (26 s updates) illustrates the opportunity to more confidently assess and track storm structures indicative of rapid intensification, the development of hail aloft, and the onset of the downdraft near the surface. These findings indicate the strong potential for rapid-update radar data to heighten forecaster confidence in the timing, location, and intensity of severe weather signatures and the possibility of increasing warning lead time, particularly on quickly developing hazards that are undersampled by the WSR-88D.
This project is completed.
Publications
Heinselman, P. L., D. L. Priegnitz, K. L. Manross, and R. Adams, 2006:
Comparison of storm evolution characteristics: The NWRT and WSR-88D.
23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc.,
CD-ROM 14.1.
Heinselman, P. L., D. Priegnitz, K. Manross, and R. Adams, 2007: Comparison of Storm Evolution Characteristics: The NWRT and WSR-88D. 23rd Conf. on Interactive Information and Processing Systems, San Antonio, TX, Amer. Meteor. Soc., CD-ROM 7.5.
Smith, T. M., P. L. Heinselman, and D. Priegnitz, 2007: Characteristics of microburst events observed with the National Weather Radar Testbed phased array radar. 23rd Conf. on Interactive Information Processing Systems, San Antonio, TX, Amer. Meteor. Soc., CD-ROM 7.8.
A time series of NWRT PAR and KTLX WSR-88D data showing the evolution of a strong microburst event on 10 July 2006. Each panel shows the vertical cross-section of reflectivity (dBZ; left) and linear least squares derivative radial divergence estimates (s-1; right) taken along the 12-km long line shown in the figure. Both the horizontal and vertical axes are given in km. The reflectivity (left) and radial divergence (right) color scales are shown at the top of the figure. The time stamps shown are for the beginning of each volume scan. Although the storm was sampled completely every 34 s, for brevity, every other cross section is displayed at ~1 min intervals.