Introduction:
This case was marked be several HP supercell thunderstorms over Lebanon and Lancaster Counites,
and a line of showers and thunderstorms that moved across Franklin, Adams, and York Counties.  As this line reached Lancaster and Lebanon Counties, the line pivoted and produced heavy rains in southern Lebanon and norhtern Lancaster Counties.

Radar estimated  rainfall was in excess of 5 inches in parts of Lebanon and Lancaster
Counties.


Method:
The hard work and ability to anticipate this event led to a good tape RIDDS tape archive
and an archive IV CDROM.  All data shown here are from the raw archive II data displayed
using WATADS.

Results
Around 2000 UTC a broken line of showers and thunderstorms formed in the warm
humid air over the lower Susquehanna Valley.  This line moved eastward.  The
first large intense storms developed over Lebanon County arournd 2210 UTC. A
cross section revealed one of these large storms over southern Lancaster County
around   2239 UTC .

Another strong storm developed over Lancaster County around  2257 UTC . And it too was large in the reflectivity  cross section .

The SRM data  revealed  weak low level convergence
and strong  storm   top divergence.


 All images  


base reflectivity data
 2314  |
 2319  |
 2324  |
 2329  |
 2334  |

Storm relative Velocity data

Velocity data



Conclusion: 
The radar rainfall estimates seemed reasonable in this case.

Storm top divergence in SRM cross sections and low-level convergence appeared
to be good indicators of storm strength. Perhaps weak convergence and strong 
divergence is a useful measure of storm severity over the lower Susquehanna Valley.
More similar cases need to be examined before this concept can be applied.