Extended Abstract (44K)P2.2
Polarimetric radar observations of a microburst-producing thunderstorm during STEPS
Kevin A. Scharfenberg, CIMMS/Univ. of Oklahoma and NOAA, Norman, OK
On June 23, 2000, a severe thunderstorm moved across the Severe Thunderstorm Electrification and Precipitation Study (STEPS) domain and produced strong microburst winds. Mobile mesonet vehicles near the storm recorded wind gusts as high as 30 m/s.
The National Center for Atmospheric Research S-band Dual Polarization Doppler Radar (S-POL) detected signatures consistent with the presence of a strong downdraft. An analysis has been made of the hydrometeor types within the downdraft column.
S-POL signatures of high horizontal reflectivity factor (ZH) and low differential reflectivity (ZDR) near ground level suggests the presence of hail, which is statistically an isotropic scatterer. In addition, the large specific differential phase (KDP) suggests the presence of non-spherical scatterers. When considered with high ZH, large KDP suggests the presence of large raindrops. Further, the decrease in the correlation coefficient (ρHV) toward the ground indicates and increasing mixture of hydrometeor types, suggesting hail was melting as it fell toward the ground within the downdraft column.
Supplementary URL: http://www.nssl.noaa.gov/~kscharf/sls02/
Poster Session 2, Convectively Driven High Wind Events
Monday, 12 August 2002, 3:00 PM-4:30 PM
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