Scottish-Irish Skier

Just over an inch of snaw here. -0.7 C. W/NW's are generally crap here in the E borders, so that's not bad at all. Bloody plough has been though, annoyingly.

You need to move a bit north. We have 2.5 cm now. No bad for a NWerly

Dusting has become a wee cm covering. Nice. Mini Miss SS said it was nearly 'superfast' snaw at times in the recent blob, but not quite. Since she originally invented the term, I had to concede.

That's mair like it. Decent blob hitting now. Might go from a dusting to a thin covering.

Home and a dusting at fort SS. Soutra has a few cms / was totally white when I crossed over.

Soutra turning white finally. Could be a fun drive home. Snaw here at Riccarton, W. Embra trying to stick and increasingly succeeding.

That's it sleeting here now. T drop rate has been nearly 3 C in 1 hour.

Woah. T dropping like a stone. Was 6 C just under an hour ago, now 3.8 C.

Blawin a hoolie and T dropping fairly quickly. Currently 5.7 C. Was 6.0 when I got up 20 mins ago. Jeez, now 5.5 C just 3 mins later as another shower lashes down.

Ha. Aye. Well, if you can see it, it's not a gas, but droplets of liquid is the general rule of thumb. 'Steam' is a grey area term. Boiled water is a gas. The stuff you can see in the bathroom when having a shower is not - it is condensed water vapour (gas condensed to liquid droplets in the air). I was not quite as detailed... Technically, water does not 'see' the air (oxygen nitrogen) at atmospheric conditions. Water does it's own thing; acts like the air isn't there. The air is not saturated nor unsaturated with water; the 'space above the ice snaw' is or is not - with gaseous water. So, if snaw / ice detects the space next to it doesn't have snaw/ice or enough gaseous water, it will evaporate to correct the balance. Easier to talk about 'air' though. The 'dew point' in terms of weather actually has really nothing to do with air - it is equilibrium between liquid/solid water and its gas phase... Don't get me started on latent cooling (e.g. when heavy snaw drops the temperature to zero). --------- Frost starting again here. Still got me cm or two or crust snaw. Thankfully not cold enough to freeze my screenwash again past couple of morns.

Sure. It's called sublimation. You'd need air passing over snaw/ice that had a water content lower than it should be in equilibrium with said snaw / ice at specific pressure and temperature. If so, snaw / ice will sublime direct to the vapour phase as it tries to reach equilibrium by saturating the air. Causes evaporative cooling# as the phase transition is endothermic. Will suck the heat ('latent heat' of vapourisation) right out of the ground and harden the frost as a result. CO2 dry ice is a classic example. At room P, it 'melts' directly to gaseous CO2. EDIT Aye. Low dew point = air undersaturated with water. Hence higher snaw / ice evaporation rates. Can cause the soil to become like concrete as moisture in it is more shielded from evaporation due to burial but yet it provides the heat (soil cools) for surface snaw/ice to sublime. #this so does not happen during heavy snow / rain to snow events.

Bloody screenwash froze the morn. Was only -2 at the hoose, but I had to go over to Gala then up the A7. There it suddenly became -6C and that was it. Canny get it fully defrosted now. It's the problem with not having quite enough anti-freeze. If you don't have quite enough, you might not notice it has frozen as when ice starts to form, the remaining liquid becomes concentrated in anti-freeze (e.g. ethanol). This is pumped onto the windscreen as it will sit at the bottom of the reservoir. All the while, what's left becomes increasingly pure water which you can't drain or get rid of through using the washers as it's frozen!

Got a wee dusting of 0.5 cm or so here overnight. Adds to the 2 cm lying. -2.2 C.

Hmm, all of a sudden something is developing of the E. Lothian coast ahead of that band heading SE. EDIT Stuck heid oot back an triggered light. Light snaw confirmed.

Met have snaw for Lauder from 18:00 to 04:00. The east coast warning will be associated with the features seen here:

Aye, 2cm feel early in the morn here too. Melting slowly at 1.6 °C. Road doesn't seem to have seen a gritter, so pretty slushy. If we get a frost tonight it will be an ice rink.

I'd be so peed off if the council did that to my snowy road.

Cheeky wee cm of snaw here in the end. 1.0 C.

Getting a wee taste of that killie streamer. Might even have cm soon. No bad for a north/westerly in the eastern borders!

Keep coming straight west-east baby.... Do not deviate.

Finally. Some light snaw.

Don't you think about draining that blob too much. I've been tracking it for an hour ok!

Aye. Nice eh! I'm at work at Heriot-Watt Campus. Lying here - fluffy dry type snaw. Quite heavy right now.

The very lightest of snaw here at Riccarton, W. Embra as a shower just brushes by to the West.