Brussels on Wednesday 29 June

Rain with thunder around midnight and in the early hours.

Rather cloudy at first on Wednesday but spells of sunshine from mid-morning
and very warm by noon. Steadily darker and more threatening from 14.00
local time as a large Cb moved in from the south.

At 14.30 a fierce thunderstorm broke out. Very dark with heavy rain with
thunder and lightning for a few minutes. From about 14.35 to 14.45 a
blinding rainstorm reduced visibility to less than 500 m. Torrents of rain
were swept along by fierce squalls, accompanied by hail and constant
thunder. Cars on the road outside the building where I work were soon
axle-deep in water. Storm then gradually abated until the rain stopped
around 15.00.

Sunny intervals for a time but from about 16.30 it was cloudy once more with
thunder now and again, the odd lightning flash, and intermittent light to
moderate rain. Thunder ceased by 19.00 and rain soon afterwards but it
stayed dull.

As a result of the storm, a number of roads in Brussels and a road tunnel
were flooded. Serious traffic hold-ups continued on the ring motorway into
the evening rush hour. There were about 50 calls to the fire service in
Brussels to deal with flooded basements and many more in the districts to
the north and east of the city. Light wind from around E in the morning;
strong and gusty in the storm; lighter and variable later.

Brussels Airport 27.3°C - overnight minimum 16.5°C - and 25 mm rain in
12 hours to 18z on Wednesday. Much of this fell in 10 to 15 mins at the
height of the storm.

SYNOP report gives the overnight rainfall total at Brussels Airport as 80 mm
but this must be a mistake - perhaps 8 mm is the correct figure.

Brussels Uccle overnight minimum 16.7°C - and 2 mm rain overnight.

NOAA 18 VIS satellite picture from Bernard Burton's site at 13.17 UTC on
Wednesday 29 June
http://www.btinternet.com/~wokingham...1317-c-fr.html
Brussels thunderstorm has now moved away NE.

Eumetsat MSG-1 satellite picture from Bernard Burton's site at 15.00 UTC on
Wednesday 29 June
http://www.btinternet.com/~wokingham...g-1500-uk.html
Massive thundery development has moved north over Belgium from France.

Rainfall radar http://weerkamer.nl/weer/radar/?uur=24 shows how quickly
the storms developed in Belgium in the early afternoon.

Graph http://www.irceline.be/cgi-bin/metevol.ksh?r012

Brussels Airport http://weather.noaa.gov/weather/current/EBBR.html

Colin Youngs
Brussels