Here in Southend-on-Sea the rain turned to snow about 8am and the air
temperature went below freezing about 11am and has hovered between -0.2
to -0.3°C since. Dew Point has been in the range of -0.6 to -1.1°C.

However, it has not really settled on hard surfaces, my raingauge has
very slowly continued tipping ever half hour or so and even the grass it
appears to be melting.

My take on it is three fold.
1. It was wet before it turned to snow.
2. Dew point temperature not a lot lower than air (High humidity)
3. Heat from sun getting through the clouds. (2) should drop later.

Just wondered if anyone had any other thoughts?

Keith (Southend)

On 07/02/2021 13:55, Keith (Southend) wrote:
Here in Southend-on-Sea the rain turned to snow about 8am and the air
temperature went below freezing about 11am and has hovered between -0.2
to -0.3°C since. Dew Point has been in the range of -0.6 to -1.1°C.

However, it has not really settled on hard surfaces, my raingauge has
very slowly continued tipping ever half hour or so and even the grass it
appears to be melting.

My take on it is three fold.
1. It was wet before it turned to snow.
2. Dew point temperature not a lot lower than air (High humidity)
3. Heat from sun getting through the clouds. (2) should drop later.

Just wondered if anyone had any other thoughts?

Keith (Southend)

How do you calibrate your sensor/s, considering you quote figures to 1
decimal place.

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
http://diverse.4mg.com/slr.htm

On 07/02/2021 14:29, N_Cook wrote:
On 07/02/2021 13:55, Keith (Southend) wrote:
Here in Southend-on-Sea the rain turned to snow about 8am and the air
temperature went below freezing about 11am and has hovered between -0.2
to -0.3°C since. Dew Point has been in the range of -0.6 to -1.1°C.

However, it has not really settled on hard surfaces, my raingauge has
very slowly continued tipping ever half hour or so and even the grass it
appears to be melting.

My take on it is three fold.
1. It was wet before it turned to snow.
2. Dew point temperature not a lot lower than air (High humidity)
3. Heat from sun getting through the clouds. (2) should drop later.

Just wondered if anyone had any other thoughts?

Keith (Southend)

How do you calibrate your sensor/s, considering you quote figures to 1
decimal place.


Thanks for your reply.

I haven't, but I should think the Davis VP2 would be reasonably
accurate, to be honest I am fairly confident they are within 0.1°C. The
temperature is now dropping and is now reading -0.8°C and it fine snow
is now starting to show on some hard surfaces.

I had a good reply from Julian Mayes, which made sense given the milder
last few days here.:

quote
Hi Keith,
As it happens I was just looking at the road-weather sensors across
Essex. It is striking from these how 'warm' the road surfaces have
become in the last 2 hours (2-3C) compared with the decreasing air
temps - these are now widely below zero and falling. It may partly be
radiation balance but also consider the soil temperature - heat flux up
to the surface. It has been mild quite recently. Do you measure soil
temps? This conduction of heat is a major factor for forecast models
predicting road surface temperature - road weather sensors have sensors
embedded 30 cm below the road surface to record this 'deep temperature'.
quote

Keith (Southend)

In message , "Keith (Southend)"
writes
Here in Southend-on-Sea the rain turned to snow about 8am and the air
temperature went below freezing about 11am and has hovered between -0.2
to -0.3°C since. Dew Point has been in the range of -0.6 to -1.1°C.

However, it has not really settled on hard surfaces, my raingauge has
very slowly continued tipping ever half hour or so and even the grass
it appears to be melting.

My take on it is three fold.
1. It was wet before it turned to snow.
2. Dew point temperature not a lot lower than air (High humidity)
3. Heat from sun getting through the clouds. (2) should drop later.

Just wondered if anyone had any other thoughts?

4, As the last few days have been mild, surfaces probably had stored
some warmth and will take a little time to cool down.
--
John Hall "Hard work often pays off after time, but laziness always
pays off now." Anon

Keith (Southend) wrote:

Here in Southend-on-Sea the rain turned to snow about 8am and the air
temperature went below freezing about 11am and has hovered between -0.2 to
-0.3°C since. Dew Point has been in the range of -0.6 to -1.1°C.

However, it has not really settled on hard surfaces, my raingauge has very
slowly continued tipping ever half hour or so and even the grass it appears
to be melting.

My take on it is three fold.
1. It was wet before it turned to snow.
2. Dew point temperature not a lot lower than air (High humidity)
3. Heat from sun getting through the clouds. (2) should drop later.

Just wondered if anyone had any other thoughts?

Keith (Southend)

Surfaces above 0C due to relatively mild temps in recent days. Had similar
experience in Tideswell today with a max temp of -0.4C yet there was a steady
thaw of snoW/ice on hard surfaces. No thaw on grass and there was steady growth
of icicles on gutters and eaves and under cars.

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

On 07/02/2021 18:25, Norman Lynagh wrote:
Keith (Southend) wrote:

Here in Southend-on-Sea the rain turned to snow about 8am and the air
temperature went below freezing about 11am and has hovered between -0.2 to
-0.3°C since. Dew Point has been in the range of -0.6 to -1.1°C.

However, it has not really settled on hard surfaces, my raingauge has very
slowly continued tipping ever half hour or so and even the grass it appears
to be melting.

My take on it is three fold.
1. It was wet before it turned to snow.
2. Dew point temperature not a lot lower than air (High humidity)
3. Heat from sun getting through the clouds. (2) should drop later.

Just wondered if anyone had any other thoughts?

Keith (Southend)

Surfaces above 0C due to relatively mild temps in recent days. Had similar
experience in Tideswell today with a max temp of -0.4C yet there was a steady
thaw of snoW/ice on hard surfaces. No thaw on grass and there was steady growth
of icicles on gutters and eaves and under cars.


Similar situations here Norman, it's frozen now as the temperatures
dropped to -1.6°C and still windy, so hopefully the next batch of snow
will settle everywhere.

Keith (Southend)

"Keith (Southend)" wrote in message
...
Here in Southend-on-Sea the rain turned to snow about 8am and the air
temperature went below freezing about 11am and has hovered between -0.2
to -0.3°C since. Dew Point has been in the range of -0.6 to -1.1°C.

However, it has not really settled on hard surfaces, my raingauge has very
slowly continued tipping ever half hour or so and even the grass it
appears to be melting.

My take on it is three fold.
1. It was wet before it turned to snow.
2. Dew point temperature not a lot lower than air (High humidity)
3. Heat from sun getting through the clouds. (2) should drop later.

Just wondered if anyone had any other thoughts?

Keith (Southend)

It is probably mainly due to radiation Keith. Looking at the Reading Uni
data
for today, because of the persistent cloud cover, the net radiation during
daylight
hours was around +120 W/m2, with short wave downward of about 180 W/m2.
This kept the grass temperature near +5C, and the temp of bare soil similar.
At 5 cm depth, the soil temp was around +6C. All of this being enough to
counter the effect of below zero wet bulb and a strong wind. The net
radiation after dark this evening is between zero and -10 W/m2, with
brief excursions down to -40 as holes in the cloud pass over.

http://www.met.reading.ac.uk/weather...WS_graphs.html


--
Bernard Burton
Weather data and satellite images at:
www.woksat.info/wwp.html