Northwest Weather Discussion

[Geordiesnow]

3 minutes ago, Chris.R said:

As long as this intensity keeps up there won't be any marginality at the surface at all all day. The only marginality is above 800 m south of Chester later in the afternoon. As temperatures increase in this layer towards 0 through the morning flakes will get bigger so expect quicker accumulation later in the morning. That's how I'm reading it.

But if the flakes get bigger, they could also be getting wetter so nothing will accumulate. It's not flake size that determines whether snow settles or not, it's the ground temperatures and air temps that are the most important factor.

[Day 10]

Low elevations really need to see those yellow echoes in the radar and at the minute there isn't any.

[Chris.R]

Just now, frosty ground said:

Interesting stuff Chris so an increase in temps at higher levels increases the moisture and intensity. Am I reading that right?

To an extent, but the main thing is  increasing temperatures at higher levels should cause snowflakes to stick together and coagulate into larger masses before they reach the surface.

[frosty ground]

2 minutes ago, Geordiesnow said:

But if the flakes get bigger, they could also be getting wetter so nothing will accumulate. It's not flake size that determines whether snow settles or not, it's the ground temperatures and air temps that are the most important factor.

But melting snow will remove heat from both the air and the surface and eventually you pass the point where snow melts 

[PsychedelicTony]

2 minutes ago, Weather-history said:

I visited Llandudno many times and I've always wondered if there has ever been lying snow where that row of houses are on the road going up to the Orme and nothing right on the promenade

Been here nearly 6 years now, formerly Chorlton that's why I still look in on the North West thread. 

Its happened a few times this year. Most years there can be at least some snow cover on the Orme but not in town. 

[Chris.R]

2 minutes ago, Geordiesnow said:

But if the flakes get bigger, they could also be getting wetter so nothing will accumulate. It's not flake size that determines whether snow settles or not, it's the ground temperatures and air temps that are the most important factor.

They are falling through a colder layer below which will dry them out again. Bigger flakes always accumulate quicker whether they are wet or not and wetter flakes will cool the ground faster.

[cheshire snow]

Heavy snow now sticking to all surfaces

[Chris.R]

3 minutes ago, frosty ground said:

But melting snow will remove heat from both the air and the surface and eventually you pass the point where snow melts 

This is the point. Melting and evaporation are endothermic. The real question is will this Endothermic cooling be enough to offset any solar radiation and will it be enough to cool the ground sufficiently to allow snow to stick properly.

[frosty ground]

Snow flake size has increased now which is starting to stick to clear spots where cars have been parked overnight 

[Alexis]

5 minutes ago, cheshire snow said:

Heavy snow now sticking to all surfaces

See. I suspect favourable "sticking conditions" are moving northwards.

[Jackski4]

Disappointing here some patchy accumulations on the grass and rooftops, seems too wet on the floor for it to begin to settle on pavements etc melting on impact.

[PennineMark]

You couldn't make this up. It's as though we're on this little island here in Dale. If the wind has yet to activate the full snow shield then god help us later on

Edited March 9, 2023 by PennineMark

[Day 10]

3 minutes ago, Jackski4 said:

Disappointing here some patchy accumulations on the grass and rooftops, seems too wet on the floor for it to begin to settle on pavements etc melting on impact.

Same here

[Joe Bloggs]

Heavier bursts of snow now in the city centre, bigger flakes. Still no settling though 

 

[James M]

Gorgeous heavy fluffy snow. Stick to surfaces but not roads. About half an inch on the grass so far.

[cambs_ry]

Just now, Joe Bloggs said:

Heavier bursts of snow now in the city centre, bigger flakes. Still no settling though 

 

The variation in intensity is really unusual! Minute to minute it’s going from 2/10 to 7/10. Bit of tease

[Spah1]

Snowing in Kirkham but no chance of any accumulation, flakes not big enough or heavy enough. 
 

At this stage if I got 5cm in Chorley I’d be delighted. 

[Chris.R]

2 cm in places here heavy small flakes at the moment.

[Joe Bloggs]

Just now, ry_mcr said:

The variation in intensity is really unusual! Minute to minute it’s going from 2/10 to 7/10. Bit of tease

I know EXACTLY what you mean. It’s so unusual isn’t it. It can’t make its mind up at all.

Still, this is better than I thought. 

[Dan B]

Still snowing here but not sticking; not heavy enough and the grounds getting very wet now

 

Still only 1ºC

[Joe Bloggs]

Rochdale appears to be the epicentre of any shield so far , the highlighted area has seen barely any precipitation all day. Must be local topography and the very specific wind vector/strength, that area will change/expand through the day. 

 

[jimben]

Light snow just starting 

[pip22]

Now gone back to light flakes now. 

Edited March 9, 2023 by pip22

[russwirral]

The back edge of the front is getting closer now.... hmmmm

[Geordiesnow]

1 minute ago, Joe Bloggs said:

Rochdale appears to be the epicentre of any shield so far , the highlighted area has seen barely any precipitation all day. Must be local topography and the very specific wind vector/strength, that area will change/expand through the day. 

 

May as well put the same marker down for here also, absolutely nothing but going by the reports, even if it did snowed, Im not missing much in terms of accumulations.

It does sadly put further emphasis I'm probably not going too see any significant snow here unless it's a set up that is slack and unexpected.