Been out for a walk, temps 5c, yet the pavements are turning slippery
and icy?

--
Joe Egginton
Wolverhampton
175m asl

Joe Egginton wrote:
Been out for a walk, temps 5c, yet the pavements are turning slippery
and icy?


Evaporative cooling?

In article ,
Joe Egginton writes:
Been out for a walk, temps 5c, yet the pavements are turning slippery
and icy?


Clear sky, pavements (and other surfaces) radiating heat. Air
temperature 5C but temperature of the surface below freezing.
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)

More to do with thge very long cold spell and depth temperatures of the
pavements. The underlying materials will noit have had chance to respond to
the milder air yet and this causes the pavements "and roads" to cool more
rapidly than they would otherwise. A similar effect is noticed at he other
end of the spectrum when strong sunshine in spring warms the underlying
surface - snow is often seen to settle on grass and not on pavements due the
same physical process.

"Joe Egginton" wrote in message
...
Been out for a walk, temps 5c, yet the pavements are turning slippery and
icy?

--
Joe Egginton
Wolverhampton
175m asl

I noted this yesterday evening, temperatures around 4ºC in a breeze, yet
concrete/tarmac (paths and roads) surfaces had ice on them. Would love to
have measured some concrete minimum's recently, but no spare thermometer.
The grass temperature was just above zero at the same time.
Alex


"Rob Brooks" wrote in message
...
More to do with thge very long cold spell and depth temperatures of the
pavements. The underlying materials will noit have had chance to respond
to the milder air yet and this causes the pavements "and roads" to cool
more rapidly than they would otherwise. A similar effect is noticed at he
other end of the spectrum when strong sunshine in spring warms the
underlying surface - snow is often seen to settle on grass and not on
pavements due the same physical process.

"Joe Egginton" wrote in message
...
Been out for a walk, temps 5c, yet the pavements are turning slippery and
icy?

--
Joe Egginton
Wolverhampton
175m asl

All my earth temperatures down to 60cm are below 2.5C at present.

Will (Haytor, Devon)
--

"Alex Stephens Jr" wrote in message
...
I noted this yesterday evening, temperatures around 4ºC in a breeze, yet
concrete/tarmac (paths and roads) surfaces had ice on them. Would love to
have measured some concrete minimum's recently, but no spare thermometer.
The grass temperature was just above zero at the same time.
Alex


"Rob Brooks" wrote in message
...
More to do with thge very long cold spell and depth temperatures of the
pavements. The underlying materials will noit have had chance to respond
to the milder air yet and this causes the pavements "and roads" to cool
more rapidly than they would otherwise. A similar effect is noticed at he
other end of the spectrum when strong sunshine in spring warms the
underlying surface - snow is often seen to settle on grass and not on
pavements due the same physical process.

"Joe Egginton" wrote in message
...
Been out for a walk, temps 5c, yet the pavements are turning slippery
and icy?

--
Joe Egginton
Wolverhampton
175m asl

The 30cm soil temperature at Birmingham Wintyerbourne is currently 0.5C - so
little heat to keep the surface from freezing. Certainly last night the
surface froze pretty easily even though the air temperature was well above
freezing.

Other interesting point is that the slush in the gutters took a very long
time to disappear - and the gutters seem to freeze up first at the
moment....

(still piles of snow and remains of snowmen around Droitwich...)

Chris


"Joe Egginton" wrote in message
...
Been out for a walk, temps 5c, yet the pavements are turning slippery and
icy?

--
Joe Egginton
Wolverhampton
175m asl

In article ,
Joe Egginton writes:
Been out for a walk, temps 5c, yet the pavements are turning slippery
and icy?


Some ice on the pavements in Cranleigh, Surrey this morning (Monday),
though no sign of frost anywhere else, not even on cars. I noticed that,
following a number of warnings for icy pavements at the end of last week
when there was no fresh ice, there was no warning out for the SE this
morning.
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)

In message , John Hall
writes
In article ,
Joe Egginton writes:
Been out for a walk, temps 5c, yet the pavements are turning slippery
and icy?


Some ice on the pavements in Cranleigh, Surrey this morning (Monday),
though no sign of frost anywhere else, not even on cars. I noticed that,
following a number of warnings for icy pavements at the end of last week
when there was no fresh ice, there was no warning out for the SE this
morning.

It lasts. I have just finished removing the compacted ice along our
rather long 'frontage'. Snow still lying here in heaps and shaded
crannies. The 'cold corner of Godalming' say the postmen. The foot of a
hill, partly in shadow for all of the day, so partial frost hollow -
not fully enclosed - and shade. Neighbours seem convinced that Wednesday
will bring more snow - MetO had dropped Surrey from the warnings when I
last looked this morning.



--
Peter Thomas

"Joe Egginton" wrote in message
...
Been out for a walk, temps 5c, yet the pavements are turning slippery and
icy?

Had a strange one about the same time as the OP, went out about 5pm and
paving slabs and some road surfaces were getting icy, it was overcast with a
light breeze and about a couple of C above.

By about 11pm the thermometer was showing less than a C above, but most of
the ice had disappeared, there was one freshly resurfaced road that's always
bad at the slightest sign of frost was a bit slippery.