Peter Nockles wrote:

On Wednesday, January 20, 2021 at 7:54:52 PM UTC, Graham wrote:
Norman Lynagh wrote:

Tideswell, Derbyshire - Wednesday 20th January 2021
---------------------------------------------------------------------


1630z 18018g29kt 7000 RA 8Sc007 08.7/08.3 975
RMK: ........and still it goes on! Total rainfall for the event
so far is 58 mm. The colder air is now moving across
Manchester so not vey far away. Max temp 9.4C and,
needless to say, there was no sunshine.
You are right there Norman. I cant believe how it. The temperature is
dropping like a stone. My Instromet thermometer has just dropped from
7.7c at 19.30 to 5.0c at 19.50, quite amazing watching it fall!!


Graham (Weston Coyney)

The rather long time-lag between the sudden temperature fall and arrival of
colder air over south Manchester compared to the Peak District and
Staffordshire uplands has also been striking. At Rostherne the temperature
fall of 3c occurred between 1500 and 1600 (it was a 5c fall between 1400 and
1600). At Buxton the sudden big temperature drop seems to have been 3 or even
4 hours later and similarly at Weston Coyney.

Peter Nockles
Didsbury
south Manchester

In Tideswell the sharp temperature fall started between 1945z and 1950z. On one
of my screens I had the Weather Underground map of temperature plots updating
at 1-minute intervals. It was fascinating to watch the very slow eastward
progress of the cold air. The forward edge of it was very well defined.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
Twitter: @TideswellWeathr