Scotland/Alba weather discussion - Jan 2021 onwards

[Coopsy]

What a forecast and what a week to be in Scotland if you’re a snow lover. Looks like parts of the NE will get relentless snow throughout the week. Lots of others doing well too. I might rent a chair in this thread for the next week if that’s ok

 

Edited February 1, 2021 by Coopsy

[101_North]

12 minutes ago, JoeShmoe said:

Sleet falling here ... will be snow id think up Stratton / currie given there's some chunky looking flakes mixed in

Nowt. Showers passing to the north. 

Edited February 1, 2021 by 101_North

[pdiddy]

5 minutes ago, Coopsy said:

What a forecast and week to be in Scotland in you’re a snow lover. Looks like parts of the NE will get relentless snow throughout the week. Lots of others doing well too. I might rent a chair in this thread for the next week if that’s ok

 

Plenty of cold rain and face-stinging sleet for many of us initially.  Must admit that the look ahead to the weekend and next week looks much more promising on this vid.

[pdiddy]

check out the strength of that Easterly!!

[Kirkcaldy Weather]

18 minutes ago, LomondSnowstorm said:

The 12Z GFS looks markedly better than the 6Z for Thursday's warm sector drama:

 

Goes on to be as near to perfection as is possible   homer could be gearing up

[jon_d1983]

16 minutes ago, Coopsy said:

What a forecast and what a week to be in Scotland in you’re a snow lover. Looks like parts of the NE will get relentless snow throughout the week. Lots of others doing well too. I might rent a chair in this thread for the next week if that’s ok

 

Guaranteed to be cold rain and howling winds for me on the Aberdeenshire Coast followed by subzero temps and bomb proof ice no doubt

[JoeShmoe]

7 minutes ago, Kirkcaldy Weather said:

Goes on to be as near to perfection as is possible   homer could be gearing up

I can't do it to myself until T+48 or less 

[Penicuikblizzard]

1 hour ago, 101_North said:

Just watching the radar and it's been interesting that for most of the day so far the echoes, even over the immediate coast, have been showing as snow north of the Forth but rain and sleet south. No idea what that means for later today and the rest of the week. Just an observation when I should really be working  

 

The Uppers are lower the further north you go,,I think we will join the fun and games Thursday evening onwards south of the Forth 

[Penicuikblizzard]

33 minutes ago, 101_North said:

Nowt. Showers passing to the north. 

Nothing here either 

[Quinach]

Like the term "Relentless snow" in that video - the Met Office better come up with it in reality

Reached a max here of 2.1c but temperature has tumbled in the last hour and currently -1.0c.

Cloud cleared up after lunch to leave a sunny afternoon bar some photogenic Cirrus...

After an absence of a few weeks, a large flock of geese has appeared nearby...

And obligatory Bennachie photo...

 

Edited February 1, 2021 by Quinach

[Klippie]

39 minutes ago, pdiddy said:

Plenty of cold rain and face-stinging sleet for many of us initially.  Must admit that the look ahead to the weekend and next week looks much more promising on this vid.

For around here all I see from this is sleety pish...so close but no cigar.

[BlueHedgehog074]

Despite not being from Scotland (and the fact these forecasts are prone to changing a lot), thought this was pretty impressive lol

[snowidea]

We've had a few snow showers today, a little sprinkle or two but nothing sticking. 

Edited February 1, 2021 by snowidea

[Sanserit]

2 hours ago, Bullseye said:

Just another day and another Snaw warning...

Looking at that some beefy snow coming in from North Sea on Friday, wouldn't rule out warnings to extend south.

Now that should keep @Mair Snawhappy!  It'll certainly keep me happy if it comes off 

[Cheggers]

Just had a brief snaw shower rattle through, radar interesting, snaw from the west, and shower flowing up the Forth. 

[scottishandy]

Had to go up a bit for my snow fix today, hopefully the last time I'll need to do that for a while! Central Gully on Ben Ledi, just a scoping mission to see if I can get my son up it when conditions align with time off.  Some nice ice starting to form. 

How many days from now until it doesn't snow do we think. I'm going for 18.

 

[LomondSnowstorm]

4 minutes ago, Cheggers said:

Just had a brief snaw shower rattle through, radar interesting, snaw from the west, and shower flowing up the Forth. 

It's quite amazing isn't it - the showers from the east are actually bumping into the band from the west over the Campsies at the moment!

[Allyw12]

I was feeling more optimistic after reading @LomondSnowstorm posts earlier.  Then I saw the bbc week ahead looks like it’s mostly rain for us in Perth  

[Bullseye]

Radar looks promising for around East Kilbride. Don't want to jinx it but central belt could be good for next few days, quite unfortunate last two weeks with snow being on marginal side here to go along with very cold temps. 

[101_North]

Just now, Allyw12 said:

I was feeling more optimistic after reading @LomondSnowstorm posts earlier.  Then I saw the bbc week ahead looks like it’s mostly rain for us in Perth  

I'd only be guessing but one of those 2 most likely has a better success rate this winter 

[pdiddy]

5 minutes ago, Allyw12 said:

I was feeling more optimistic after reading @LomondSnowstorm posts earlier.  Then I saw the bbc week ahead looks like it’s mostly rain for us in Perth  

the BBC WA was bust as of yesterday as was completely based on flawed 0z ECM yesterday.  Wait for tonight's!

Edited February 1, 2021 by pdiddy

[Serac]

It’s getting a bit atmospheric out there now 

 

[pdiddy]

BBC have changed from 2c and sleet to 1c and snow for Edinburgh tomorrow morning

 

and then immediately changed it back again!

 

Edited February 1, 2021 by pdiddy

[Sceptical]

A cold night incoming, currently minus 6C.

[LomondSnowstorm]

A small look at the soundings for just before the main front arrives, based on the NMM. This is for Coatbridge at 6am:

the precip map:

 

Going through some of the key variables:

Freezing level - check (under 350m)

Wet bulb freezing level - also check (less than 300m from the surface)

Surface temperature - fine enough (around 1-1.5C or so, bearing in mind the surface has a lower pressure than 1000hPa)

Dew point - meh (0.5C or so)
 

Twet - not bad (1C or so)

Uppers - around -6C at this point so fine

 

Overall you'd probably expect it to be snow, but the reason I'd maybe be a little more confident comes from this paper (it's a bit lengthy but a good read, maybe for a time when there's less nowcasting to do!) https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjS3Z_OosnuAhXtVRUIHXBnA_QQFjAAegQIBRAC&url=http%3A%2F%2Fwww.diva-portal.se%2Fsmash%2Fget%2Fdiva2%3A968860%2FFULLTEXT01.pdf&usg=AOvVaw1b5qEOXtTdFZZOiLiyY4UL

 

Basically,the conditions are perfect for the 'melting effect' on latent heat (I think I've described it as evaporative cooling in the past but that's slightly different) whereby the snow melting at higher levels uses up heat energy and causes the temperature to drop to near freezing over a layer of maybe a few hundred metres. I'm sure we've seen this a couple of times or more this winter so far, and it's particularly pronounced with persistent, moderate to heavy precipitation as we're likely to see early tomorrow, and also with a near saturated surface layer as we're likely to have (near 100% humidity). The one caveat to this is primarily areas of low temperature advection, and this is where it might not be enough closer to the coast (I'll post a sounding for Fife and maybe the Lothians if it's different after I've had my tea) or if the easterlies are very strong, and of course if we get the full warm sector at any point it won't be sustainable. However, I just wanted to give a bit of theoretical basis to what we're looking for tomorrow.