Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: P. L. MacKeen x
  • Refine by Access: All Content x
Clear All Modify Search
P. L. MacKeen
,
H. E. Brooks
, and
K. L. Elmore

Abstract

In order for the Federal Aviation Administration (FAA) to use airspace more efficiently during thunderstorm events, accurate storm longevity forecasts are needed. Relationships between 16 radar reflectivity–derived storm characteristics and storm longevity are examined to determine which, if any, of the storm characteristics are strongly related to storm lifetime. Such relationships are potentially useful for the development of storm longevity forecasts. The study includes 879 storms that formed over the Memphis, Tennessee, area during 15 late spring and summer convective days. Statistical analyses comparing all 16 storm characteristics to the observed remaining lifetime show that these storm characteristics are not good predictors for storm remaining lifetime.

Full access
R. A. Maddox
,
D. S. Zaras
,
P. L. MacKeen
,
J. J. Gourley
,
R. Rabin
, and
K. W. Howard

Abstract

The new Doppler radars of the National Weather Service (i.e., the WSR-88D radars) are operated continuously in a volume scanning mode (called Volume Coverage Pattern, VCP) with the elevation tilt angles fixed for several VCPs. Because of the fixed VCPs, the radar data can be used to determine the heights of precipitation echo features only to limits of accuracy that depend upon the elevation angles used in the VCP, the radar beamwidth, and the range of echoes. Data from adjacent WSR-88D radars, if used simultaneously, could reduce significantly the height uncertainties inherent in single radar measurements. This is illustrated for idealized situations and also for an event involving a long-lived, tornadic thunderstorm. The use of coordinated scan strategies and combined data analysis procedures for adjacent WSR-88D radars during significant thunderstorm events should be considered for operational applications.

Full access