RaVeNStOrM

THUNDERSTORM T0011
Date: Friday 8th May 1998   Time: 23:55-00:48 BST
Location:
Macclesfield, Cheshire UK
Path: Overhead

Synoptics:
Early continental plume
Duration: 53 minutes
Type: Mid-level multicell
Average lightning type: C-C
Average discharge rate: 2 minutes
Footage Quality:
VHS

 

This was the first substantial overhead thunderstorm for 1998 for Macclesfield, and it was dramatic in itís fury. It was fairly large, close-by, and we had clear displays of blue lightning in the night-sky after the clock struck midnight, one of which gave a thunder loud enough set car alarms off and buffet the windows.



It was a humid day with a warm-sector continental airmass feeding up from Spain and France. London reached its highest temperature of the year so far at 25įC. The airmass, likely with preconditioned instability from Iberia, was destabilising ahead of an extending upper trough associated with an Atlantic depression. The system was heading north-westwards and on the precipitation radar there was an area of speckled showers (light to moderate) over the Midlands heading northwards. Initially I thought they would either dissipate or just pass over lightly and unnoticed, but I prepared myself just in case anything developed. The next radar image I saw wasn't for a few hours (the days before internet - relying heavily on BBC weather) so I had to stay alert.

As midnight was drawing in, I hung out of the window to smell the warm and humid spring air of the night, and I thought that it was a perfect atmosphere for a night-time storm (traditionally). As I thought that, a faint distant flash occurred in the corner of my left eye, so I prepared the camera. As it drew in closer, I started to hear some distant thunder with the lightning flashes, which meant it was within a good 15-20 mile thunder-audibility range. I started to film pointing towards the west based on the flashes I saw. After a few more discharges the lightning was starting to get brighter and closer and it started raining. It was then I realised the storm must have been approaching from the southwest.

I then told myself, based on errors I made during 1997, that if an overhead storm did eventually come today then aim the camera up at a higher angle into the sky and forget about the horizon (for CGs), so I could to capture any overhead I-C or C-C lightning. So I aimed the camera upward and it was about to pay off. Eventually the rain fell harder as the storm passed directly overhead, giving a total of four excellent close-up displays of C-C, I-C and a few other distant C-Cs and flashes. I wouldnít have got these brilliant new shots if I hadnít have aimed the camera upwards.

The first C-C took me completely by surprise. I hadn't realised this particular cell was directly overhead (must have matured whilst arriving) until I was blinded by two incredibly bright C-Cs streaks across the sky. I had to blink afterwards it was that bright as I could still see the outline of the lightning burnt into my retinas, and if that wasnít enough I was quickly deafened as well. Precisely eight seconds after the discharge the most phenomenal thunder Iíve ever heard (still to this date in 2020) crashed across the landscape setting off car alarms and buffeting the windows (more about this later). The following close-by C-Cs werenít as energetic as the initial. This I can justify because the second C-C was exactly the same distance away judging off the thunder, maybe a fifth of a mile closer, and the thunder wasnít even half as loud. This shows how lightning can vary in electrical properties depending on the magnitude and environmental conditions of the discharge. Most of the remaining lightning discharges were seen as C-Cs with branches and feelers, somewhat extremely photogenic and beautiful.

Here are some detailed statistics of the initial loud thunder at the beginning. It took 8 seconds for the first thunder-waves to travel from the lightning to where I was, which was equivalent to approximately 1.6 miles away (2.67km). This is a fair distance for a thunder of this magnitude. Unusually high-amp lightning, possibly C-C in conjunction with an unseen P-F (positive flash) occurrence, was most likely the cause of this. The thunder was about 30 seconds in duration suggesting that it may have been of upper-anvil origins with a long channel.

ANALYSIS OF THUNDER

Time (seconds)

Length (seconds)

Description

0.0

1.8

Build Up

1.8

2.5

1st set of bangs - 5 Loud Bangs

4.3

0.5

Main Rumble and Aftershock Rumbles

4.8

2.0

2nd set of bangs - 3 Longer Bangs

6.8

23.2

Aftershock Rumble and Echoes

30.0

 

End

SFERICS (Credits)
EUROPE 24-hour 8th May SFERIC LOCATION

EUROPE 24-hour 9th May SFERIC LOCATION

CHARTS (Credits)



 

SATELLITE IMAGES (Credits)
VISIBLE 08.05.1998 16:46

INFRARED 08.05.1998 16:46
COLOUR 08.05.1998 16:46


INFRARED 09.05.1998 03:35

 


 
© Mark Seltzer  www.electricsky.co.uk

 

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