Casebook 18 August 2003: Difference between revisions

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==CSU-CHILL Casebook: 18 August, 2003==
==CSU-CHILL Casebook: 18 August, 2003==


A thunderstorm briefly became severe near the foothills west-southwest of Loveland Colorado during the afternoon of 18 August 2003.  The CSU-CHILL radar made an RHI scan through the echo core of this storm at 2010:32 UTC.  Sweep 3 of this RHI volume intercepted both a nearby light rain area (containing a bright band) as well as the more distant hailstormPolarimetric signatures of both the melting layer in the bright band and the hail shaft in the thunderstorm can be seen.
A thunderstorm briefly became severe near the foothills west-southwest of Loveland Colorado during the afternoon of 18 August 2003.  The CSU-CHILL radar made an RHI scan through the core of this storm at 2010:32 UTC.  (See VCHILL example below.) The ZDR field contains a bright band in the low reflectivity elevated echo layer near the 20 km range pointIn the high reflectivity thunderstorm core, the transition from positive to near 0 dB ZDR values near the surface at a range of 58 km indicates an increasing hail fraction in the precipitation.  Finally, a three-body scattering signature (distinctly negative ZDR at low elevations changing to large positive values at higher elevation angles) can be seen at the far range end of the thunderstorm.
 
[http://chill.colostate.edu/java/vchill.php?sweep=xlab.chill.colostate.edu:2510*/dsk/dnf/data/2003/08/18/%20DIR*CHL20030818_201032%20MPRHI1%20RHI*Sweep%2003&center=0.,0.&range=75.&plot=ZDR example in VCHILL]


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Revision as of 06:35, 24 December 2007

CSU-CHILL Casebook: 18 August, 2003

A thunderstorm briefly became severe near the foothills west-southwest of Loveland Colorado during the afternoon of 18 August 2003. The CSU-CHILL radar made an RHI scan through the core of this storm at 2010:32 UTC. (See VCHILL example below.) The ZDR field contains a bright band in the low reflectivity elevated echo layer near the 20 km range point. In the high reflectivity thunderstorm core, the transition from positive to near 0 dB ZDR values near the surface at a range of 58 km indicates an increasing hail fraction in the precipitation. Finally, a three-body scattering signature (distinctly negative ZDR at low elevations changing to large positive values at higher elevation angles) can be seen at the far range end of the thunderstorm.

example in VCHILL

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