THUNDERSTORM T0010
Date: Tuesday 28th April 1998 Time: 20:45
BST
Location:
Macclesfield, Cheshire UK
(storm over Stockport)
Path: Cell 1: Developed overhead, matured 10-20 miles north /
Northwards
Synoptics: Open cell convection
Duration: 1 hour
Type: Rearward sloping Multicell
Average lightning type: C-G
Average discharge rate: 53 seconds
Footage Quality: VHS
Compared with T0009, this was an absolute beast. However it developed
overhead and matured several miles north where the thunder was
in-audible. The good news was it occurred during the late-evening, so the
lightning was clearly visible.
It
was substantially active considering it was a slow-moving mid-spring
open-cell storm. The air-mass is hard to judge looking at the past satellite
imagery; but the Met Office analysis chart below indicates it was likely
returning polar. It was a surprisingly warm day at 24C for an RT airmass,
perhaps a small cap was present.
A cluster
of storm cells were moving in at around 20:00 UTC whilst in their
development stages. One of these cells was about 30 miles away East over the
Pennines that showed prominent cell growth at the front, and a solid wedge-shaped anvil
at the rear, indicating a shear environment favouring forward-propagating
cells (rearward sloping).
The developing cells quietly rolled over Macclesfield only giving a light
shower in the form of large raindrops. A few minutes later after it had past
to the north I heard a rumble of thunder. I had a look out of the window to
analyse the horizon and saw a further lightning flash to the north. The base
didn’t look very structured nor did it appear to have much in the way of
precipitation curtains, so initially I thought I was filming an inactive
cell that fortunately gave a discharge on the off-chance. That was ruled out
shortly after it started splashing C-G and C-C lightning all over the place
with a reasonable discharge rate.
After a further two flashes I zoomed the camera in to where I the lightning
hotspot was.
As
it was a slow-mover, this storm was seen from Macclesfield to produce a rough
total of 33 discharges as the storm matured over parts of
Stockport and southern Manchester. Thirty of these discharges were recorded
on camera. Most of these discharges were visible C-G or C-Cs, sometimes
accompanying each other. The discharges rates were somewhat uneven though,
some quiet periods and some active periods, indicating the "pulse" nature of
tower development.
DUNDEE SATELLITE IMAGES (Credits)
VISIBLE 28.04.1998 17:07
INFRARED 28.04.1998 17:07
COLOUR 28.04.1998 17:07
|