Search Results

You are looking at 1 - 7 of 7 items for :

  • Plains Elevated Convection At Night (PECAN) x
  • Refine by Access: All Content x
Clear All
Hristo G. Chipilski, Xuguang Wang, David B. Parsons, Aaron Johnson, and Samuel K. Degelia

bore-generating nocturnal convection within the 10 PECAN cases used herein. The data assimilation (DA) period usually covered the time from the initial formation of convective cells ( Fig. 1a ) to their upscale growth and eventual merging into a mesoscale convective system (MCS) with a well-developed surface-based cold pool ( Fig. 1b ). It is worth noting that while surface-based cold pools do not necessarily form in all nocturnal MCSs (e.g., Maddox 1980 ; Trier and Parsons 1993 ), they occurred

Restricted access
Yun Lin, Jiwen Fan, Jong-Hoon Jeong, Yuwei Zhang, Cameron R. Homeyer, and Jingyu Wang

few studies that examine the combined effects of both pathways (i.e., land and aerosol effects) on lightning and precipitation. A new observational study ( Kar and Liou 2019 ) indicated that both land and aerosol effects should be considered to explain the cloud-to-ground lightning enhancements over the urban areas. Modeling studies have shown that land-cover changes increase precipitation over the upstream region but decrease it over the downstream region, while the aerosol effect was opposite

Full access
David J. Bodine and Kristen L. Rasmussen

and β = 0.0088 to correct . WSR-88D calibration was also checked by examining the mean throughout the period of study in dry snow regions identified by the PID algorithm. The mean value of 0.20 dB compares well with the expected value for dry snow aggregates of less than 0.25 dB ( Ryzhkov et al. 2005 ). After data processing steps are completed, the processed radar data are interpolated onto a three-dimensional grid through the following process. Radar data are linearly interpolated on

Full access
Manda B. Chasteen, Steven E. Koch, and David B. Parsons

humidity, weak near-surface stability, low-level turbulent mixing, and enhanced surface winds. This moisture plume was evident in the ASOS observations at 0900 and 1200 UTC as the northward protrusion of high dewpoint temperatures and dense low-level cloud cover located over central Texas ( Figs. 12a,b ). Moreover, enhanced surface winds were observed within the moisture plume, but the observed wind speeds were 5 kt slower than the simulated 10-m wind speeds over much of the region (not shown). This

Full access
Jonathan E. Thielen and William A. Gallus Jr.

. Quantitative morphology analysis Given that bow echoes and linear modes with stratiform regions are among the most poorly forecasted modes ( SG14 ; Carlberg et al. 2018 ) and are associated with some of the highest occurrences of severe hazards ( G08 ), further investigation into the details of the errors of morphology depiction is needed for these modes. One important parameter related to system morphology is the total area covered by an MCS, which for BE and stratiform linear modes is most often

Full access
Samuel K. Degelia, Xuguang Wang, and David J. Stensrud

the FP sites. After 2100 UTC, the inner domain is initialized within the outer domain and conventional, PECAN, and level-2 Weather Surveillance Radar-1988 Doppler (WSR-88D) observations are assimilated at 10-min cycling intervals from 2110 UTC 25 June to 0000 UTC 26 June. Because the WSR-88D network sufficiently covers the domain of interest, we choose not to assimilate any special radar data collected by PECAN instruments. The radar observations assimilated in this study (radar reflectivity

Full access
Rachel L. Miller, Conrad L. Ziegler, and Michael I. Biggerstaff

front ( Fig. 1 ). The deployment strategy positioned the radars in six contiguous triangular subarrays ( Fig. 1b , Table 1 ) that provided overlapping sampling volumes and covered baselines to affect optimal multiple-Doppler analysis ( Ray et al. 1978 ; Ray et al. 1979 ; Ray et al. 1980 ; Ray and Sangren 1983 ; Ziegler et al. 1983 ; Ziegler et al. 1991 ; Kessinger et al. 1987 ; Ziegler 2013b ). Table 1. Characteristics of the radar array from which multi-Doppler radar analyses were

Free access