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Typhoon Herb

On July 31, 1996 Typhoon Herb roared across Northern Taiwan resulting in the loss of many lives and damage to property due to high winds, flooding, and landslides. One of the locations receiving heavy damage was the WSR-88D radar facility located at the Northern tip of Taiwan, 30 KM east northeast of Taipei. The facility, operated by Taiwan's Central Weather Bureau, collected reflectivity and velocity data as the Typhoon approached and was forced to shut down as the eye of the storm grew closer and the threat of water damage to the radar electronics increased. Eight hours after the facility shut down, high winds ripped the fiber glass panels from the radar instrumentation and flung them down the hillside. Doppler Radar analysis of the storm showed peak wind speeds of 82 m/s at the 1 km level. Below we show a comparison between observed data collected by the Radar installation before it was shut down and MM5 model data generated by researchers at the National Center for Atmospheric Research. One of the unique characteristics of Typhoon Herb is its elliptical shaped eye.
Observed Data   Model Data

Observed data timestep 73

QuickTime | Real | MPEG

In the observed data there is a stationary hole directly above the radar location at the center of the image. This hole represents missing data which are an artifact of the conical radar beams that project from the radar source.

  Model data timestep 73

QuickTime | Real | MPEG

The model data generated by the MM5 model is nonhydrostatic and uses a terrain-following sigma coordinate. The model physics include parameterization for the surface and planetary boundary layer, and cloud microphysics. It also includes prediction of rain water/snow, cloud water/ice and graupel, cumulus convection, and atmospheric radiation.

Model Name:
Observed Radar Data from WSR-88D installation in Northern Taiwan
July 31, 1996 at 6 am
Time Evolution:
7 hours
Time Resolution:
6 minutes
Horizontal Real World:
Observed 1.5 km, Model 6.6 km
Tim Scheitlin
Wen-Chau Lee
Wei Wang
Bill Kuo
Date Catalogued:
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