North West England Regional Weather Discussion - 09/12/2017 Onwards

[Chris.R]

1 minute ago, SP1986 said:

One thing that happens now that never used to happen is that sometimes you get snow and I'll get rain. In the old days you could bet that being 100m up I'd get snow while you got rain.. not so simple these days.

 Is that definitely different? We‘ve talked before about how I am in somewhat of a frost hollow which  encourages inversions.  I do think a lot of that is luck, in that I got heavier precipitation than you perhaps.   

[SP1986]

1 hour ago, Day 10 said:

Just out of interest the sea surface temperature by Crosby today is 8.9C with the average for this time of the year being 9.6C. So a little below which is surprising.

Maybe what we are seeing then is an instance of higher dewpoints when it mattered.. that's hasn't been lost on me .. for example in one of the cold spells in December we had -10C at 850hPa with 522 DAM ... Not for most that would be enough for snow however here the dewpoint was +1C which is bizarre given the conditions ... So maybe we have to look towards a general rise in dewpoints for our poor form... Which would make sense in a climate change scenario as more moisture would be available in the air... In theory .

[SP1986]

4 minutes ago, Chris.R said:

 Is that definitely different? We‘ve talked before about how I am in somewhat of a frost hollow which  encourages inversions.  I do think a lot of that is luck, in that I got heavier precipitation than you perhaps.   

In an inversion scenario with clear skies etc you can be much colder than here however when the air is moving you are generally milder than I am .. or at least that was the case in the past. It is possible of course you got heavier ppn (evaporative cooling) as I am in a rain shadow in comparison .

Edited December 30, 2017 by SP1986

[SP1986]

PS it's nice that we are starting to scrutinise and understand the limitations of our area with regard to these setups. 

[Mokidugway]

1 minute ago, SP1986 said:

PS it's nice that we are starting to scrutinise and understand the limitations of our area with regard to these setups. 

Pure desperation,awaiting solutions  well ,ones that don't involve moving 100s of cubic kilometres of dirt that is .

Edited December 30, 2017 by Mokidugway

[Chris.R]

9 minutes ago, SP1986 said:

In an inversion scenario with clear skies etc you can be much colder than here however when the air is moving you are generally milder than I am .. or at least that was the case in the past. It is possible of course you got heavier ppn (evaporative cooling) as I am in a rain shadow in comparison .

 How about situations with light winds and  heavy precipitation, evaporative cooling like the 15th and last night?  That’s the situation which is so curious because the air isn’t moving much then either. 

Edited December 30, 2017 by Chris.R

[northwestsnow]

43 minutes ago, SP1986 said:

PS it's nice that we are starting to scrutinise and understand the limitations of our area with regard to these setups. 

Yes ste i agree.

I'm not sure where we can find Irish sea temps over a rolling 30 or even 40 year period.

As cheese rice says, in a PM set up it says a hell of a lot when places just over the pennines are snowier than places less than 20miles to the west with 200m altitude!

In an easterly/North easterly the irish sea becomes irelevant- its no coincidence that east/north east winds are now virtually extinct in the Dec/Jan/Feb months - they were much more common in the period 1978-187...(and so was snowfall).

[Frost HoIIow]

1 hour ago, Cheese Rice said:

Its the Irish sea that really does it, generally speaking temperatures across the central belt of Northern England are usually the same in winter. 

Where it matters is when setups are marginal, North West England does particularly poorly in these setups, especially in the last 3-4 years that have been characterized by a lack of deep cold. The wind of the Irish sea can make the difference between 1-2.c, we are lucky here that we are sheltered by the pennines so tend to do well in marginal scenarios.

NW England is definitely one of the worst places for lying snow in the country 

 

Not really, some coastal parts of Yorkshire have not seen measurable snow since 2013 because in the east you really need an easterly to deliver the goods but easterlies are rare, also northerlys are not what they used to be due to the warming Arctic, whereas I have had settling snow at least once in each winter since then because we've had more PM air than continental, even the atrocious winter of 2013-14 I had a pathetic dusting one evening in the February, most places in the UK did not see a flake in that winter. In fact apart from Highland Scotland no where in the UK does very well for snow, we have a maritime climate after all -  sort of like some parts of the Pacific NW of US & Canada with just bits of snow every now and then which rarely lasts because of mild air waiting in the wings. 

[Cheese Rice]

PM setups over the last few winters don't tend to deliver in the NW either, or at least over the last few years they haven't. There has been countless times when the North West has been buzzing the day before a PM flow and it always amounts to a wintry mixture or temporary accumulations. Even here though they tend to fall as snow they only really result in temporary accumulations. 

[Mokidugway]

Back to wind , not looking like much of an event here 

[Frost HoIIow]

2 minutes ago, Cheese Rice said:

PM setups over the last few winters don't tend to deliver in the NW either, or at least over the last few years they haven't. There has been countless times when the North West has been buzzing the day before a PM flow and it always amounts to a wintry mixture or temporary accumulations. Even here though they tend to fall as snow they only really result in temporary accumulations. 

I must have been imagining the snow then because various PM flows have delivered here, temporary or not it's still snow on the ground rather than bare concrete which most on this forum would crave especially folk down south. it's mostly members closer to the coast I the NW that miss out on PM flows but not here in the East of the region. Don't kid yourself that Yorkshire does much better than here because it doesn't. Most inland places in the North do pretty similarly for snow amounts. Like I say only Highland Scotland gets reliable heavy snow most Winters but even here you're talking about over 300m where some sheep live, most of the Scottish populous don't experience alot of snow. 

[Stratocumulus perlucidus]

8 minutes ago, Mokidugway said:

Back to wind , not looking like much of an event here 

Yep. Snow goes south and wind goes north!!! Cant win

[SP1986]

Proudman Observatory located on Hilbre Island has some good data sets for Irish Sea Surface temperatures but I'm not sure how far back the data goes.

As for the local area.. well I used to be a big snow ramper on BBC snow watch if anyone remembers it.. but when I discovered an interest in local microclimates I moved away from ramping to an interest in local microclimates.. this unfortunately got me the label of mild ramper.

Knowing full well the massive differences that occur from coast to inland I sought to adapt to our less than desirable climate by developing an interest in exotic plants knowing the climate may actually be able to sustain exotic plants so I pioneered some things like growing Citrus outside permanently. 

To this day the differences interest me greatly.. to me a night of 1C while it's -7C in Manchester interests me as much as snow. If Liverpool had snow and here had rain that would be as interesting as the other way round

[dodge]

Two north westerlies in 2009/10 delivered foot falls of snow on both occasions to my back yard and local district.  Although I haven't had a fall of snow that depth of level since then.  However there have also been many let downs from this source and it could easily lead to a thoroughly wet miserable cold rain day instead of snow.

I can't remember the last time a pure driven easterly fed in snow showers this far west.  North Easterlies no matter how cold tend to have their snow baring gifts shredded over the tops of the Pennines delivering diddly squat on our side.  That's when you see pictures of places like Aberdeen and Northumberland buried in snow.  Northerlies give the wishbone effect, so no snow from them.  Anything coming up from the south/south west tends to fizzle out by the time it reaches my area or slides and pivots away to the south.  So all in all, it's got to be Polar Maritime from the North West, with disturbances which could lead to the fabled Polar Low and all its resulting glory.

[Mokidugway]

Whatever direction I need an offshore breeze at low level to even think of snow 

[SP1986]

31 minutes ago, dodgeredee said:

Two north westerlies in 2009/10 delivered foot falls of snow on both occasions to my back yard and local district.  Although I haven't had a fall of snow that depth of level since then.  However there have also been many let downs from this source and it could easily lead to a thoroughly wet miserable cold rain day instead of snow.

I can't remember the last time a pure driven easterly fed in snow showers this far west.  North Easterlies no matter how cold tend to have their snow baring gifts shredded over the tops of the Pennines delivering diddly squat on our side.  That's when you see pictures of places like Aberdeen and Northumberland buried in snow.  Northerlies give the wishbone effect, so no snow from them.  Anything coming up from the south/south west tends to fizzle out by the time it reaches my area or slides and pivots away to the south.  So all in all, it's got to be Polar Maritime from the North West, with disturbances which could lead to the fabled Polar Low and all its resulting glory.

2007/2008 saw snow get to the other side of the Pennines although the precipitation was light it produced a cm due to the ground being so cold. I was in Childwall in Liverpool at the time studying but sadly it didn't make it as far as west Wirral.

[SP1986]

Hmm is it just me or is that wind field much further south than forecast?

Edit: I think it actually is on track but the initial wave of low pressure was fairly southwards

Edited December 30, 2017 by SP1986

[northwestsnow]

Well the latest gfs might offer the opportunity for a NEwind next weekend!

Uppers around -7 i reckon will suffice in my back yard, if it pans out like that of course.

[Mokidugway]

16 minutes ago, northwestsnow said:

Well the latest gfs might offer the opportunity for a NEwind next weekend!

Uppers around -7 i reckon will suffice in my back yard, if it pans out like that of course.

Quiet here at mo ,next week is lost to as away .f

Edited December 30, 2017 by Mokidugway

[chicken soup]

1 hour ago, northwestsnow said:

Well the latest gfs might offer the opportunity for a NEwind next weekend!

Uppers around -7 i reckon will suffice in my back yard, if it pans out like that of course.

From a selfish point of view  I really hope not...easterlies or bilge for here.

 

[Iceaxecrampon]

15 hours ago, Mokidugway said:

Whatever direction I need an offshore breeze at low level to even think of snow 

......what is Snow? 

[Iceaxecrampon]

Bit of a letterbox lifting breeze this am. Talk of an Easterly on the MO discussion getting them all in a froth. Waiting for the inevitable warm sectors and freezing rain that's if the Pennines don't soak it all up. ?

[SP1986]

If it happens as it stands it will last maybe 24 hours.. nothing to get too excited about and not a huge amount a cold air embedded in it either.

[dodge]

Quite a bit of bog standard cold falling H20 to get through this week looking at the forecast.  Barely one day without the rain droplet in the graphics.

[Had Worse]

1 hour ago, Iceaxecrampon said:

......what is Snow? 

Scraping the inside of the freezer will get you powder snow then it goes slushy which is as close to what you get falling where you live.