Snow

[Mossdog]

Make that half an inch.

Still just a dusting here Mike, with the makings of a temp. inversion brewing. Nice and crispy though.

[anthonykay]

So, having spent a few days in Scotland amidst dire warnings of snow "10 cm or more", when no more than a dusting of the tops appeared, I returned home to the North Pennines on Thursday to "Tier 3 warnings" and claims of "unprecedented low temperature for this time of the year" plus "heavy snow from 16:00 hrs on Thursday". Again, just a few paltry flakes and a heavy persistent frost `(kind of what you'd expect in December!).

I wonder, when did our weather forecast adopt such dramatic hyperbole? Click-bait? Sensationalist media inflation? WTF!

The Met Office is in Exeter. Normal temperatures in the North Pennines really are unprecedented low temperatures down there.

[Travs]

Weather has been massively over-dramatised since the advent of 24hr tv news.

Got to fill the hours somehow. ie live coverage of a news reporter standing on a slightly windy seafront.

[Mossdog]

What I find particularly amusing is how a few days of high, record breaking temperatures in the summer (and the usual doom-laden crisis pronouncements) this is cited as evidence of scary global warming.

Yet when we have a run of unprecedented very cold days in the winter, suddenly that's not contrary evidence about global warming, rather it's dismissed as "just weather, not climate". Go figure!

[noel]

Yes, but just think how cold it would have been without global warming. Keep running your cars everyone

[Mike T]

Several days in a row now the overnight frost has been so heavy it looked, in Ambleside, like a light snowfall, but the last snow at this level was 9th/10th of December.

There is a small tarn near Lily Tarn that is only ever about 2 feet deep at the most. It is of course frozen over; the ice is broken in a couple of places, and it is about 2 and a half to 3 inches thick. People and dogs have been walking on it. I understand that ice needs to be at least 4 inches thick for it to be safe to walk on.

[noel]

I remember reading in the excellent book Schott's Miscellany, of the weight bearing properties of different ice thicknesses. Thankfully someone on the UK hillwalking forums has transcribed it - thank you whoever Ron is:

Theoretically 'safe' thickness of ice for different weights; from Schotts original miscellany, Ben Schott. Not sure exactly how it was calculated, it assumes solid blue/black ice.
all values in inches

single person on skis 1.5
single person on foot 2.5
Group in single file 3
Snowmobile 3
Average car 7.5
Large car 8
Medium truck3.5 tons 9
7tons 10
15 tons 15
25 tons 20
45 tons 25
70 tons 30
I am not sure whether these values are factored.
Don't blame me if it isn't right.
Ron

[Mossdog]

Re Ice. It seems sea ice extent is on a gradual increase in the Antarctic while on a decrease in the arctic - since 1979. What's that about?

https://osisaf-hl.met.no/v2p1-sea-ice-index

[Marco]

I remember reading in the excellent book Schott's Miscellany, of the weight bearing properties of different ice thicknesses. Thankfully someone on the UK hillwalking forums has transcribed it - thank you whoever Ron is:

Theoretically 'safe' thickness of ice for different weights; from Schotts original miscellany, Ben Schott. Not sure exactly how it was calculated, it assumes solid blue/black ice.
all values in inches

single person on skis 1.5
single person on foot 2.5
Group in single file 3
Snowmobile 3
Average car 7.5
Large car 8
Medium truck3.5 tons 9
7tons 10
15 tons 15
25 tons 20
45 tons 25
70 tons 30
I am not sure whether these values are factored.
Don't blame me if it isn't right.
Ron

So how much ice is required for an overweight 14 year old, (so not me, then), riding a modified Raleigh Chopper across an East Staffordshire reservoir?

[anthonykay]

Re Ice. It seems sea ice extent is on a gradual increase in the Antarctic while on a decrease in the arctic - since 1979. What's that about?

https://osisaf-hl.met.no/v2p1-sea-ice-index

The data in that webpage show no clear trend at all in the Antarctic, whereas there is a clear decrease in the Arctic.

In any case, increasing temperatures in very cold regions can lead to more ice. Air at -10C can hold more water vapour than air at -20C, so an increase in temperature in that range can lead to more precipitation, which would still fall as snow.