RaVeNStOrM

PASSING STORM PS0003
Date: Friday 4th June 1999   Time: 22:40 BST
Location:
Macclesfield, Cheshire UK
Path: ~40 miles away to the northwest (west Lancashire)

Synoptics:
Returning polar maritime airflow
Duration: 20 minutes
Type: Open-cell convection, likely aided by land convergence
Average lightning type: I-C
Average discharge rate: 256 seconds
Footage Quality:
VHS/Hi8

 

I saw this group of fast developing cells on the horizon in a line and decided to set the camera to time-lapse mode and watch them grow. They all shot up quickly to form anvils and started to merge with each other into a long convergence line about 40-50 miles away NW of Macclesfield over the west coast of Lancashire (Southport/Blackpool).

One of the cells, which was at the time disappearing behind a set of trees, became electrically active as I spotted a flash of lightning. At this point I started filming normally and zoomed right up to the cells. A cell behind this one also became active and it continued to flash faintly. The updraught development was observed to be at the front, with the anvil sloping backwards, showing that the surface wind and steering flow (~850-750hPa) was stronger than the upper Tropospheric flow, indicative of an upper-vortex sitting right overhead (see charts below indicating 500mb vortex nearby). I caught one good discharge that lit up the front part of a developing cell.


SATELLITE IMAGES (Credits)
COLOUR 04.06.1999 17:23 + GRID

COLOUR 04.06.1999 17:23
INFRARED 04.06.1999 17:23 + GRID
INFRARED 04.06.1999 17:23
VISIBLE 04.06.1999 17:23 + GRID
VISIBLE 04.06.1999 17:23

CHARTS (Credits)



SFERICS (Credits)


 
Mark Seltzer  www.electricsky.co.uk

 

Web Analytics