The 'Great Ottery Hailstorm' of the 30th October 2008

The 30th October 2008 has got to be one of the most memorable 'weather' nights ever. A
thunderstorm with hail of the intensity I have not witnessed before.
 

This picture shows the depth of the hail stones (not snow as the mdeia reported) at one of the lowest points in Ottery St Mary. The rain had washed the hailstones down from higher ground and they all collected here, blocking all the drains. This looks like a snowy scene more typical of January. Then again, even in January snow is a rare sight, let alone in October. Actually, this is a hail scene but from a distance it does look like snow. You can see where the hail had been washed down to the lower points of the Otter Valley by the prolonged torrential rain.

The evening of the 29th October started very much normal with just steady rain and a temperature around 6C. This carried on until 23:45 when the first flash of ligntning occurred, and it was directly overhead. The rain intensity then started to increase and the lightning became progeressively more frequent with overhead flashes accompanied by immediate, deafening claps of thunder every 30 seconds or so. By 00:30 the rain was torrential and hail started to fall as well but the really heavy hail did not fall for another 15 to 20 minutes though by 01:00 the hail and rain were evenly mixed. At this location the hail did not accumulate much as we are situtated on a slight hill so all the hail was being washed away in all directions. Interesting to note though that I have never recorded hail and rain together with such intensity and to last so long i.e., more than 1 hours.

At 01:15 the rain was falling at a rate of 10 mm every 15 minutes and with the hail it sounded like an express train was thundering along the roof of the house. The thunder and lightning was spectacular with frequent, multiple overhead flashes and of such a brightness I have not experienced before.

To describe the intensity of the rainfall is hard, but if you imagine a summer thunderstorm when you often get a short but incredible deluge of rain that seems to flood everywhere in just a few minutes, then that would be similar to the rainfall that was occurring during this storm, but instead of lasting 5 or 10 minutes, this lasted 2 hours.

41 mm of rain fell between 00:00 and 03:00 with a total of 71 mm falling between midnight and 08:00. It must be noted though that these figures probably under-represent the real rain that fell due to the gauges getting blocked by hailstones.

The media was reporting that snow was falling but I can write here that there definitely was no snow, just hail and lots of it.

Met Office rainfall radar of the Otter Valley from 21:00 to 03:00.

The town of Ottery St Mary was particularly badly affected as the town is situated quite low down in the Otter Valley and surrounded by hills and higher ground. The streets were turned into rivers which was washing the hail to the lowest point in the town which was the Finnimore Indutrial Estate where the hail collected in large drifts over a metre deep in places.

 

A car entombed in hail ice on the Finnimore Industrial Estate, Ottery St Mary

 


Met Office rainfall radar at 03:30 on the 30th October 2008. Note the rather tame looking green line running roughly NW-SE just east of Exeter. The hailstorm was so localised that the resultion of this chart is too low to show what was really falling.

 
 
   
   
Figure 1. October 30th 00:00. The centre of the low pressure that the storms were embedded in was situated just to the north west of the Otter Valley here in south-east Devon.

 

Figure 2. October 30th 06:00. The centre of the low pressure has drifted south-wards and after the storm there was just ordinary rain from the occluded front that passed over the area.
   
 A lightning strike over nearby Bradninch.
 

Please Note!

All the photos on this web page were not taken by myself and were sent to me by well-meaning individuals, and because of this I have no idea who took the photos in the first place. I would like to accredit the owners of these photos so if anyone knows who did take them then please email me and I can then give credit and thanks to the original owners.