New WSR-88D Volume Coverage Pattern 12: Results of Field Tests

Brown, Rodger A.; Wood, Vincent T.; Steadham, Randy M.; Lee, Robert R.; Flickinger, Bradley A.; Sirmans, Dale

doi:10.1175/waf848.1

Cited by 34 publications

(14 citation statements)

References 5 publications

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“…This southern cell began to merge with the main supercell at nearly the exact time of tornadogenesis (;1956 UTC; Fig. By completion of the merger with the southern cell, a distinct tornadic vortex signature (Brown et al 1978), quasi-circular TDS (Ryzhkov et al 2002(Ryzhkov et al , 2005, and Z DR arc (Kumjian and Ryzhkov 2008) were all apparent, along with classic supercellular Z HH and y r structures (Fig. 2c).…”

Section: A Early Tornado Trackmentioning

confidence: 96%

High-Temporal Resolution Polarimetric X-Band Doppler Radar Observations of the 20 May 2013 Moore, Oklahoma, Tornado

Kurdzo

Bodine

Cheong

et al. 2015

Monthly Weather Review

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On 20 May 2013, the cities of Newcastle, Oklahoma City, and Moore, Oklahoma, were impacted by a longtrack violent tornado that was rated as an EF5 on the enhanced Fujita scale by the National Weather Service. Despite a relatively sustained long track, damage surveys revealed a number of small-scale damage indicators that hinted at storm-scale processes that occurred over short time periods. The University of Oklahoma (OU) Advanced Radar Research Center's PX-1000 transportable, polarimetric, X-band weather radar was operating in a single-elevation PPI scanning strategy at the OU Westheimer airport throughout the duration of the tornado, collecting high spatial and temporal resolution polarimetric data every 20 s at ranges as close as 10 km and heights below 500 m AGL. This dataset contains the only known polarimetric radar observations of the Moore tornado at such high temporal resolution, providing the opportunity to analyze and study finescale phenomena occurring on rapid time scales. Analysis is presented of a series of debris ejections and rear-flank gust front surges that both preceded and followed a loop of the tornado as it weakened over the Moore Medical Center before rapidly accelerating and restrengthening to the east. The gust front structure, debris characteristics, and differential reflectivity arc breakdown are explored as evidence for a ''failed occlusion'' hypothesis. Observations are supported by rigorous hand analysis of critical storm attributes, including tornado track relative to the damage survey, sudden track shifts, and a directional debris ejection analysis. A conceptual description and illustration of the suspected failed occlusion process is provided, and its implications are discussed.

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Section: A Early Tornado Trackmentioning

confidence: 96%

High-Temporal Resolution Polarimetric X-Band Doppler Radar Observations of the 20 May 2013 Moore, Oklahoma, Tornado

Kurdzo

Bodine

Cheong

et al. 2015

Monthly Weather Review

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“…3). KDDC collected data continuously at 4.1-min intervals in the Greensburg storm, including its initiation at 0030 UTC 1 In volume coverage pattern 12 (VCP12; Brown et al 2005), a WSR-88D executes a ''step spiral'' scanning pattern, cycling through 14 elevation angles ranging from 0.58 to 19.58. We used 37 volumes of KDDC Z and V r data, from 0029 to 0302 UTC.…”

Section: A Wsr-88d Datamentioning

confidence: 99%

EnKF Assimilation of High-Resolution, Mobile Doppler Radar Data of the 4 May 2007 Greensburg, Kansas, Supercell into a Numerical Cloud Model

Tanamachi

Wicker

Dowell

et al. 2013

Monthly Weather Review

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Mobile Doppler radar data, along with observations from a nearby Weather Surveillance Radar-1988 Doppler (WSR-88D), are assimilated with an ensemble Kalman filter (EnKF) technique into a nonhydrostatic, compressible numerical weather prediction model to analyze the evolution of the 4 May 2007 Greensburg, Kansas, tornadic supercell. The storm is simulated via assimilation of reflectivity and velocity data in an initially horizontally homogeneous environment whose parameters are believed to be a close approximation to those of the Greensburg supercell inflow sector. Experiments are conducted to test analysis sensitivity to mobile radar data availability and to the mean environmental near-surface wind profile, which was changing rapidly during the simulation period. In all experiments, a supercell with similar location and evolution to the observed storm is analyzed, but the simulated storm's characteristics differ markedly. The assimilation of mobile Doppler radar data has a much greater impact on the resulting analyses, particularly at low altitudes (#2 km), than modifications to the near-surface environmental wind profile. Differences in the analyzed updrafts, vortices, cold pool structure, rear-flank gust front structure, and observation-space diagnostics are documented. An analyzed vortex corresponding to the enhanced Fujita scale 5 (EF-5) Greensburg tornado is stronger and deeper in experiments in which mobile (higher resolution) Doppler radar data are included in the assimilation. This difference is linked to stronger analyzed horizontal convergence, which in turn is associated with increased stretching of vertical vorticity. Changing the near-surface wind profile appears to impact primarily the updraft strength, availability of streamwise vorticity for tilting into the vertical, and lowlevel vortex strength and longevity.

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“…Only cases that utilized VCPs 11 and 12 ( Fig. 1) were chosen due to their higher vertical resolution when compared with VCPs 21 and 121 (Brown et al 2005).…”

Section: Methodsmentioning

confidence: 99%

Evaluation of a Technique for Radar Identification of Large Hail across the Upper Midwest and Central Plains of the United States

Donavon

Jungbluth

2007

Weather and Forecasting

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Radar data were analyzed for severe thunderstorms that produced severe hail (Ͼ19 mm diameter) across the central and northern plains of the United States during the 2001-04 convective seasons. Results showed a strongly linear relationship between the 50-dBZ echo height and the height of the melting level-so strong that a severe hail warning methodology was successfully deployed at the National Weather Service Warning and Forecast Offices in North Dakota and Iowa. Specifically, for each of 183 severe hailstorms, the 50-dBZ echo height near the hail event time was plotted against the depth of the environmental melting level. Linear regression revealed a coefficient of determination of 0.86, which suggested a strong linear relationship between the 50-dBZ echo height and the melting-level depth for the severe hail producing storms. As the height of the melting level increased, the expected 50-dBZ echo height increased. A severe warning criterion for large hail was based on the 10th percentile from the linear regression, producing a probability of detection of 90% and a false alarm rate of 22%. Additional analysis found that the 50-dBZ echo-height technique performs very well for weakly to moderately sheared thunderstorm environments. However, for strongly sheared, supercell-type environments, signatures such as weak-echo regions and three-body scatter spikes led to more rapid severe thunderstorm detection in many cases.

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New WSR-88D Volume Coverage Pattern 12: Results of Field Tests

Cited by 34 publications

References 5 publications

High-Temporal Resolution Polarimetric X-Band Doppler Radar Observations of the 20 May 2013 Moore, Oklahoma, Tornado

High-Temporal Resolution Polarimetric X-Band Doppler Radar Observations of the 20 May 2013 Moore, Oklahoma, Tornado

EnKF Assimilation of High-Resolution, Mobile Doppler Radar Data of the 4 May 2007 Greensburg, Kansas, Supercell into a Numerical Cloud Model

Evaluation of a Technique for Radar Identification of Large Hail across the Upper Midwest and Central Plains of the United States

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