July 22nd
Intense mesoscale storms over the Midlands
The synoptic
situation on the 22nd was that of a weak southerly flow from the continent over England ahead of a cold front, which at 00Z
was lying from W Scotland through to SE Ireland and was moving very slowly ESE. See the synoptic analysis here : http://www.wetterzentrale.de/archive/2004/brack/bracka20040722.gif
An MCS (Mesoscale
Convective System) developed out of a small cell in the Bristol area only a few miles across during the early afternoon
and quickly grew into a small but intense storm. It tracked in a NNE/NE direction across Gloucestershire and Worcestershire,
all the time intensifying. Cirencester was first in the firing line, some heavy rain and frequent CG (Cloud ground lightning
strikes) were observed. Stow-on-the-Wold in the SW Midlands was also hit with the storm producing
some localised flooding and numerous violent lightning strikes. During the thunderstorm a report came in from an unassuming
observer of the rare weather phenomena ‘ball lightning’ near to Stow-on-the-Wold!
The storm continued
its track NE through the heart of the Midlands to the east of Birmingham; day turned to almost night under the tall cumulonimbus
clouds and torrential rain it brought, reducing visibilities dramatically, the skies all the time illuminated by the constant
and intense fork lightning.
