"George Booth" wrote in message
...

In another post John O'Rourke reported a depoint of 2°C at Heathrow at
14:50; this is about 20 miles from here so I have no reason to think
myreading was incorrect.

Alan

The lowest dewpoint here was 14° here. However a quick look at METARS to
the
west showed values similar to yours. The boundary shows up nicely here
http://tinyurl.com/3t2pd


Apologies, only for registered users. But registration is free! (and well
worth it)

--
George

I'm registered anyway so it was no problem to me . An very interesting
image - I could see some cloud in the Epping direction at the time aththough
is was completely clear overhead.I have downloaded the data for the period
which I show below; times are GMT. The console showed a DP mimimum of 4°C
which is slightly lower than the 15min minimum of 4.8°C.
Out
Date Time Hum Dew

07/08/2004 07:45 80 17.7
07/08/2004 08:00 73 17.6
07/08/2004 08:15 68 17.2
07/08/2004 08:30 65 17.1
07/08/2004 08:45 62 16.4
07/08/2004 09:00 59 16.2
07/08/2004 09:15 58 16.2
07/08/2004 09:30 55 15.8
07/08/2004 09:45 51 15
07/08/2004 10:00 48 14.5
07/08/2004 10:15 45 13.7
07/08/2004 10:30 46 14.1
07/08/2004 10:45 41 12.8
07/08/2004 11:00 40 12.6
07/08/2004 11:15 38 11.8
07/08/2004 11:30 35 10.6
07/08/2004 11:45 27 7.1
07/08/2004 12:00 29 8.5
07/08/2004 12:15 27 7.6
07/08/2004 12:30 23 5.3
07/08/2004 12:45 22 4.8
07/08/2004 13:00 26 7.4
07/08/2004 13:15 24 6.3
07/08/2004 13:30 27 7.9
07/08/2004 13:45 26 7.7
07/08/2004 14:00 24 6.8
07/08/2004 14:15 26 8.2
07/08/2004 14:30 26 7.7
07/08/2004 14:45 25 7.3
07/08/2004 15:00 26 7.9
07/08/2004 15:15 26 8
07/08/2004 15:30 26 8
07/08/2004 15:45 25 7.3
07/08/2004 16:00 27 8.3
07/08/2004 16:15 28 8.7
07/08/2004 16:30 28 8.6
07/08/2004 16:45 27 7.9
07/08/2004 17:00 28 8.2
07/08/2004 17:15 29 8.5
07/08/2004 17:30 30 9
07/08/2004 17:45 29 8.7
07/08/2004 18:00 33 10.6
07/08/2004 18:15 46 15.4
07/08/2004 18:30 51 15.7

Alan

In uk.sci.weather on Sun, 8 Aug 2004 at 12:54:00, Alan Gardiner wrote :

Dewpoint dropped to 4°C

Surely not? There's been no CF that I've seen?

this afternon from 17°C this morning in St Albans.

In another post John O'Rourke reported a depoint of 2°C at Heathrow at
14:50; this is about 20 miles from here so I have no reason to think
myreading was incorrect.

But what could cause such low dewpoints in the midst of such a warm &
humid spell?
--
Paul Hyett, Cheltenham