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Date: 07-07-2004
Time: 01:09 BST
Location:
Macclesfield, Cheshire UK
Type: Local Convectional Wave (upper-level PV)
Documented by: Mark Seltzer
Equipment: Samsung VP-H65 Video Camera
Footage Quality: Hi-8
Storm Statistics:
T0049.doc
Event Timeline:
T0049events.xls
This was one of the most energetic night time storms I’ve filmed yet and the
only storm where I know I’ve captured the actual initial discharge. It
developed directly overhead in the slack flow at around 1:00am shortly after
T0048 had dissipated. Like T0048, this cell was associated with an
upper-level trough preceding a Spanish Plume low-system to the south. In
fact the plume was way to the south and still over northern France at the
time this was occurring, so it was probably a completely un-associated area
of PV maxima.
At first the cell was
electrically silent but the precipitation was torrential overhead. With this
and also knowing that this was a thunderstorm-generating system I decided to
put the camera up in hope of catching something else for the night.

INITIATION DISCHARGE
Shortly after I did so,
the first discharge of the cell (initiation discharge) happened in the form
of an overhead C-C followed by a great crash of thunder. Then within more or
less every minute there was a discharge, mostly C-Cs, some high amp and some
low. The high-amp discharges were very bright and the thunder was often
bassy. This showed strong and steady development occurring within the cell.

The discharge shown above was very bright
and aggressive and as a result had a very loud thunder even from a distance.
The following discharge was beautiful and tame in comparison showing a
slight orb-fashion shape in the C-C.

The line between the updraught and downdraught was starting to become evident as C-C spiders and
crawlers danced just in between them.



I
was confident there were minimal C-G strikes as the storm initiated just as
it left the area, giving a clear view of the whole main cloud base. The
storm was visible for more than an hour and a half as it slowly creeped its
way northwards giving some immense displays of C-C, often with “call and
response” characteristics between two parts of the storm. The silhouette of
a strong bubbly updraught-base was also revealed with every discharge
situated at the rear of the storm (back-fed).



This next one was a rather good
discharge, as well as lighting up the underside of the updraught base a long
C-C spider-crawler shot from left to right and then connected with the
ground halfway though.


This was one of the best
night-time storms I’ve filmed after T0011 and T0024. It was very easy to
film as the storm cell had already left the area (no blustery rain to
contend with), but in a slack flow left plenty of action to see. It was very
organised and local, and it was heading northwards which meant no changes of
camera angle required from a north-facing room. The entire line of cells
dissipated around about the time I stopped filming at 2:50am.
DUNDEE
SATELLITE IMAGES
(CREDITS)
INFRARED 06.07.2004 22:13
INFRARED 06.07.2004 22:13 + GRID
INFRARED 07.07.2004 04:48
INFRARED 07.07.2004 04:48 + GRID
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