Squall line
10 Mar 2011



Squall Line


An intense well organised squall line crossed the UK on the 24th of October 1995. The figures below show four parameters recorded with the Chilbolton Advanced Meteorological Radar (CAMRa) during the passage of the squall line. The high values of reflectivity (top left) indicate rainfall rates in excess of 80 mm/hr. The presence of large drops in this region is clear from the differential reflectivity signature (bottom left), while the linear depolarisation ratio, LDR (top right) suggests significant raindrop canting in the turbulence.

The melting layer can also be clearly recognised at around 70 km range in the LDR signature. Differential phase (bottom right) changes very rapidly through the intense line of precipitation, again due to the presence of large, oblate raindrops and provides a second estimate of path indicated rainfall rate.

Radar scan showing LDR  
Radar scan showing  Zdr  
Radar scan showing  PhiDP  
Contact: Hooper, David (STFC,RAL,RALSP)