Date: 18-03-2007   Time: 18:10 GMT
Macclesfield, Cheshire UK
Storm Stage: Mature then dissipating
Path / Movement:
Overhead / SE
Footage Quality:

A deep low had established itself over Scandinavia with a centre of 956mb. The result was a strong and cool drag of polar maritime air mass across the UK from the North West. This produced some fairly beefy wintry showers across the country, especially in northern and western areas, mostly of sleet hail and snow. The showers were intermittent all day across the North West and parts of Manchester, and getting stronger throughout the afternoon as the sun warmed up. I was actually in Manchester during the day and was driving home at 16:30. It was only then I noticed how strong the sleet & hail showers were getting as the roads gradually turned white before my eyes.

At about 18:00 back in Macclesfield a strong squall of convection started appearing on the northern horizon, with a large glaciated anvil top featuring a bit of mammatus in the sunset. Not expecting to see any thundery activity at this time of year (and also in a polar air stream), I decided to think nothing of it and go back to my normal activities. I then started to notice in the corner of my eye the wall by the side of me flash bright orange every so often, and at first thought it was the TV or my imagination. But then I decided to investigate so I opened the window to behold a distant thunder.

The Canon XM2 was now tracked on the low-hanging cloud base to the north which had a short 5-minute burst of electrical activity before falling silent. There were C-Cs observed along the whole squall-line and also a bright C-G to the NW that occurred off-camera. It was obvious on the radar that the squall was intense as it showed up as a thin red wave which had appeared as if from nowhere (giving away fast development).

As the squall drew closer it was evident that the precipitation was going to be intense. It went almost night-black (in the setting sun) and a strong white hail-shaft was clearly zeroing in on the NW horizon.

The result was 4-8mm hail mixed in with sleet in an absolute white-out deluge for about 10 minutes. The untreated road outside my house turned white within this time frame and cars were struggling to get grip even at <5mph as they rolled over the fresh layer of loose ice. There was only one overhead lightning discharge at this point and it was a weak affair, and then fell silent again as it rolled south-eastwards.