South West & Central Southern England Regional Discussion 26th January 2013

[cerneman]

Quick glance at the medium to long range potential tonight, leant towards the search for colder, Wintery weather.

We have good confidence now of a mid Atlantic high pressure system setting up next week. Something like this will be typical midweek;

What this does is block the Atlantic depressions from smashing into the UK as they have done so recently. This is also known as zonal. What looks like happening now is the Atlantic depressions look like being deflected north over the mid Atlantic high in the northern arm of the Jet Stream;

You can see above the Jet Stream riding over the high, hence the amplitude in the Jet Stream. These then come back down south in the North Sea and into mainland Europe, forming a Euro trough;

The red in the Atlantic being the mid Atlantic high, the blue over Europe being the Euro trough. What this will bring to our part of the world is colder than average conditions, summed up nicely below;

However, whilst some snowfall is possible on elevated areas of our region, it would still remain very marginal for most of our region due to modified warm sectors raising Dewpoints and WBFL values. Things like this aren't worth speculating until much nearer a potential event anyway, but I wouldn't rule out surprise snowfall cropping up on embedded troughs in the flow for some next week, indeed I half expect it.

Beyond next week, I tend you back to a paint job I did a couple of days ago.

Here I mention the probability of the Mid Atlantic high starting to topple over towards the UK after a couple of failed attempts trying to get into the Greenland area. Well, is there a sign of this in the models;

Yep, timing aside, this scenario is gaining support as we enter week 2 on tonight's runs. This then sends WAA (warmer Atlantic air) up towards the Iceland corridor;

Similiar to my paint job chart above. What this does is help start of height rises in the GIN corridor, nearer the Norway side I think however;

Bingo. The last frame of the ECM Det starting to show this develop. Whilst this takes place however, do expect a brief return to near average temperatures as mentioned in the Met Office 5-15 day forecast. This is because whilst WAA is being sent up north, the high has to topple, bringing less cold air for us temporarily.

Now what I expect to happen beyond the ECM is a bit clearer tonight, if indeed the current model output verifies. Back to my paint jobs, it would be something similiar to what I said a couple of days ago. This;

Ignore the black line for now. Height rises becoming a player towards the Iceland/Norway area and a euro trough digging further south into Southern Europe. This scenario would bring the cold air over Europe here;

Westwards over the UK. The ECM anomaly chart for week 2 represents my thoughts well;

So, I'm very happy about where we are heading currently, but it is stil a long term trend that has a long way to go still so caution is most definetly still required. The trend gas gained momentum tonight in the 12z data, that's all we need at the moment.

- coolnext week for the most part, just not quite cold enough for reliable snowfall, however, if everything is timed right, surprise transient/wet snowfall is possible for some, elevation key here

- do expect a recovery to near normal temperatures briefly towards the end of next week as the sypnotic pattern sets itself up for the main event. Also expect drier conditions.

- cold mid February from the east/north east/north still looking good, still my long range punt. How cold and if it will be accompanied on snowfall remains to be seen. My guess at the stage is not mega cold but easily cold enough for snow, which we will see at some point being closer to the Euro trough.

All looking fine still guys. We can but hope.

You really make your forecasts and thoughts very clear. Excellent for people like me who find it hard follow charts,,,,,,,,,,,,,,,,,,,

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

Yuk, don't look at the radars guys. The only glimmer of excitement over the coming hours is that there are some sferics showing up SW of Ireland, but other than that, its RAIN RAIN RAIN.

Hi!

At least there is some consistency on the models over the next 7 days and its nowhere near as chaotic as the last spell!

[Beast of Plympton]

Quick glance at the medium to long range potential tonight, leant towards the search for colder, Wintery weather.

We have good confidence now of a mid Atlantic high pressure system setting up next week. Something like this will be typical midweek;

What this does is block the Atlantic depressions from smashing into the UK as they have done so recently. This is also known as zonal. What looks like happening now is the Atlantic depressions look like being deflected north over the mid Atlantic high in the northern arm of the Jet Stream;

You can see above the Jet Stream riding over the high, hence the amplitude in the Jet Stream. These then come back down south in the North Sea and into mainland Europe, forming a Euro trough;

The red in the Atlantic being the mid Atlantic high, the blue over Europe being the Euro trough. What this will bring to our part of the world is colder than average conditions, summed up nicely below;

However, whilst some snowfall is possible on elevated areas of our region, it would still remain very marginal for most of our region due to modified warm sectors raising Dewpoints and WBFL values. Things like this aren't worth speculating until much nearer a potential event anyway, but I wouldn't rule out surprise snowfall cropping up on embedded troughs in the flow for some next week, indeed I half expect it.

Beyond next week, I tend you back to a paint job I did a couple of days ago.

Here I mention the probability of the Mid Atlantic high starting to topple over towards the UK after a couple of failed attempts trying to get into the Greenland area. Well, is there a sign of this in the models;

Yep, timing aside, this scenario is gaining support as we enter week 2 on tonight's runs. This then sends WAA (warmer Atlantic air) up towards the Iceland corridor;

Similiar to my paint job chart above. What this does is help start of height rises in the GIN corridor, nearer the Norway side I think however;

Bingo. The last frame of the ECM Det starting to show this develop. Whilst this takes place however, do expect a brief return to near average temperatures as mentioned in the Met Office 5-15 day forecast. This is because whilst WAA is being sent up north, the high has to topple, bringing less cold air for us temporarily.

Now what I expect to happen beyond the ECM is a bit clearer tonight, if indeed the current model output verifies. Back to my paint jobs, it would be something similiar to what I said a couple of days ago. This;

Ignore the black line for now. Height rises becoming a player towards the Iceland/Norway area and a euro trough digging further south into Southern Europe. This scenario would bring the cold air over Europe here;

Westwards over the UK. The ECM anomaly chart for week 2 represents my thoughts well;

So, I'm very happy about where we are heading currently, but it is stil a long term trend that has a long way to go still so caution is most definetly still required. The trend gas gained momentum tonight in the 12z data, that's all we need at the moment.

- coolnext week for the most part, just not quite cold enough for reliable snowfall, however, if everything is timed right, surprise transient/wet snowfall is possible for some, elevation key here

- do expect a recovery to near normal temperatures briefly towards the end of next week as the sypnotic pattern sets itself up for the main event. Also expect drier conditions.

- cold mid February from the east/north east/north still looking good, still my long range punt. How cold and if it will be accompanied on snowfall remains to be seen. My guess at the stage is not mega cold but easily cold enough for snow, which we will see at some point being closer to the Euro trough.

All looking fine still guys. We can but hope.

Brilliant AWD. As cerneman says, very clear and informative for people who can't read charts like you. Its very easy to get lost in the mod thread with technical terms and I end up not reading properly because I just don't understand what is being said. Not to blow smoke up your bottom but i'm glad you are a southwestern occupant and please stay in here!!

[dec10snow]

Quick glance at the medium to long range potential tonight, leant towards the search for colder, Wintery weather.

We have good confidence now of a mid Atlantic high pressure system setting up next week. Something like this will be typical midweek;

What this does is block the Atlantic depressions from smashing into the UK as they have done so recently. This is also known as zonal. What looks like happening now is the Atlantic depressions look like being deflected north over the mid Atlantic high in the northern arm of the Jet Stream;

You can see above the Jet Stream riding over the high, hence the amplitude in the Jet Stream. These then come back down south in the North Sea and into mainland Europe, forming a Euro trough;

The red in the Atlantic being the mid Atlantic high, the blue over Europe being the Euro trough. What this will bring to our part of the world is colder than average conditions, summed up nicely below;

However, whilst some snowfall is possible on elevated areas of our region, it would still remain very marginal for most of our region due to modified warm sectors raising Dewpoints and WBFL values. Things like this aren't worth speculating until much nearer a potential event anyway, but I wouldn't rule out surprise snowfall cropping up on embedded troughs in the flow for some next week, indeed I half expect it.

Beyond next week, I tend you back to a paint job I did a couple of days ago.

Here I mention the probability of the Mid Atlantic high starting to topple over towards the UK after a couple of failed attempts trying to get into the Greenland area. Well, is there a sign of this in the models;

Yep, timing aside, this scenario is gaining support as we enter week 2 on tonight's runs. This then sends WAA (warmer Atlantic air) up towards the Iceland corridor;

Similiar to my paint job chart above. What this does is help start of height rises in the GIN corridor, nearer the Norway side I think however;

Bingo. The last frame of the ECM Det starting to show this develop. Whilst this takes place however, do expect a brief return to near average temperatures as mentioned in the Met Office 5-15 day forecast. This is because whilst WAA is being sent up north, the high has to topple, bringing less cold air for us temporarily.

Now what I expect to happen beyond the ECM is a bit clearer tonight, if indeed the current model output verifies. Back to my paint jobs, it would be something similiar to what I said a couple of days ago. This;

Ignore the black line for now. Height rises becoming a player towards the Iceland/Norway area and a euro trough digging further south into Southern Europe. This scenario would bring the cold air over Europe here;

Westwards over the UK. The ECM anomaly chart for week 2 represents my thoughts well;

So, I'm very happy about where we are heading currently, but it is stil a long term trend that has a long way to go still so caution is most definetly still required. The trend gas gained momentum tonight in the 12z data, that's all we need at the moment.

- coolnext week for the most part, just not quite cold enough for reliable snowfall, however, if everything is timed right, surprise transient/wet snowfall is possible for some, elevation key here

- do expect a recovery to near normal temperatures briefly towards the end of next week as the sypnotic pattern sets itself up for the main event. Also expect drier conditions.

- cold mid February from the east/north east/north still looking good, still my long range punt. How cold and if it will be accompanied on snowfall remains to be seen. My guess at the stage is not mega cold but easily cold enough for snow, which we will see at some point being closer to the Euro trough.

All looking fine still guys. We can but hope.

As always, thanks for your great analysis, we're lucky to have you here

I know it's a very guesswork based punt, but I assume you would believe the CET to come in below average?

[gottolovethisweather]

Hi!

At least there is some consistency on the models over the next 7 days and its nowhere near as chaotic as the last spell!

RAIN RAIN RAIN, do let us know when you're thinking of going on holiday.

[gottolovethisweather]

Looking once again at the longer-term outlook, another post suggestive of what I believe will be a key timeframe, if we are to get a final fling from PROPER WINTER. Of course, I still have next week on my mind but that will most probably be a case of one day average temps, one day cool enough for wintriness and exchanging from one to tother.

http://forum.netweat...80#entry2580258

This also falls nicely in line with AWDs posts from the last few days too.

Edited January 31, 2013 by gottolovethisweather

[AWD]

Small line of shower cells running up the Bristol Channel heading for South Gloucestershire ahead of the main band of rain approaching the SW.

[AWD]

Interesting FAX chart for Tuesday;

Notice a number of troughs in circulation in the North Westerly flow, under sub 528DAM air! Mmmmmmm..............!

[AWD]

I know it's a very guesswork based punt, but I assume you would believe the CET to come in below average?

Indeed. With more in the way of colder than average temperatures rather than warmer than average being hinted at, its certainly favouring a colder than average CET at this early stage.

[Bristawl Si]

Interesting FAX chart for Tuesday;

Notice a number of troughs in circulation in the North Westerly flow, under sub 528DAM air! Mmmmmmm..............!

Ah yes - slightly longer days; increased risk of convectional activity; north westerly polar maritime flow - our region, esp the western parts and cotswolds affected thru the Cheshire Gap can do OK out of this type of set up.

Increasing cold as well, I suspect.

Edited January 31, 2013 by Bristle boy

[legritter]

Looking fairly good for us next week i feel .things could pop up unexpectantly .in this type of synoptic situation we dont necessarily need bone chilling temperatures just some active weather systems coming our way .i remember a similar set up back in the 80 s whilst living in bristol we had a trough come in from west overnight temp at 11pm only 4 c but by midnight it was snowing hard and we got a good 12cms followed by about the same 48hrs later .back in 1969 we had a good fall of 15cms as a small but slow moving low moved from irish sea over our area similar set up as what is being modelled for next week .tonights rain just starting to hit parts of somerset with some hvy rain now over cornwall .anyhow im off up the stairs ,cheers all .

[Karl83]

Quick glance at the medium to long range potential tonight, leant towards the search for colder, Wintery weather.

We have good confidence now of a mid Atlantic high pressure system setting up next week. Something like this will be typical midweek;

What this does is block the Atlantic depressions from smashing into the UK as they have done so recently. This is also known as zonal. What looks like happening now is the Atlantic depressions look like being deflected north over the mid Atlantic high in the northern arm of the Jet Stream;

You can see above the Jet Stream riding over the high, hence the amplitude in the Jet Stream. These then come back down south in the North Sea and into mainland Europe, forming a Euro trough;

The red in the Atlantic being the mid Atlantic high, the blue over Europe being the Euro trough. What this will bring to our part of the world is colder than average conditions, summed up nicely below;

However, whilst some snowfall is possible on elevated areas of our region, it would still remain very marginal for most of our region due to modified warm sectors raising Dewpoints and WBFL values. Things like this aren't worth speculating until much nearer a potential event anyway, but I wouldn't rule out surprise snowfall cropping up on embedded troughs in the flow for some next week, indeed I half expect it.

Beyond next week, I tend you back to a paint job I did a couple of days ago.

Here I mention the probability of the Mid Atlantic high starting to topple over towards the UK after a couple of failed attempts trying to get into the Greenland area. Well, is there a sign of this in the models;

Yep, timing aside, this scenario is gaining support as we enter week 2 on tonight's runs. This then sends WAA (warmer Atlantic air) up towards the Iceland corridor;

Similiar to my paint job chart above. What this does is help start of height rises in the GIN corridor, nearer the Norway side I think however;

Bingo. The last frame of the ECM Det starting to show this develop. Whilst this takes place however, do expect a brief return to near average temperatures as mentioned in the Met Office 5-15 day forecast. This is because whilst WAA is being sent up north, the high has to topple, bringing less cold air for us temporarily.

Now what I expect to happen beyond the ECM is a bit clearer tonight, if indeed the current model output verifies. Back to my paint jobs, it would be something similiar to what I said a couple of days ago. This;

Ignore the black line for now. Height rises becoming a player towards the Iceland/Norway area and a euro trough digging further south into Southern Europe. This scenario would bring the cold air over Europe here;

Westwards over the UK. The ECM anomaly chart for week 2 represents my thoughts well;

So, I'm very happy about where we are heading currently, but it is stil a long term trend that has a long way to go still so caution is most definetly still required. The trend gas gained momentum tonight in the 12z data, that's all we need at the moment.

- coolnext week for the most part, just not quite cold enough for reliable snowfall, however, if everything is timed right, surprise transient/wet snowfall is possible for some, elevation key here

- do expect a recovery to near normal temperatures briefly towards the end of next week as the sypnotic pattern sets itself up for the main event. Also expect drier conditions.

- cold mid February from the east/north east/north still looking good, still my long range punt. How cold and if it will be accompanied on snowfall remains to be seen. My guess at the stage is not mega cold but easily cold enough for snow, which we will see at some point being closer to the Euro trough.

All looking fine still guys. We can but hope.

Great post mate. Very informative.

[Dorsetbred]

Well it's Friday 6am, no wind and 3.6mm of rain and pressure still above 1000mb, after the "storm" it certainly confirms the original fax charts, it was to be a "storm in a t-cup"

Edited February 1, 2013 by Dorsetbred

[Coast]

But how much of it will we still catch on the South coast then:

[Dorsetbred]

But how much of it will we still catch on the South coast then:

Nora lot, it seems to hold more of an easterly component to the overall direction, so the Channel activity "might" just clip the SE.

[Coast]

GFS says even that is a remote chance:

But then it also says for Monday:

Or Wednesday?

Edited February 1, 2013 by Coast

[Coast]

Still a way to go before anything that's left of the wind is likely to get here (and you may not even notice it anyway!). XC Weather show Ireland has some low impact stuff currently:

[Mapantz]

Loved being under a yellow warning for 8mm of rain.

[AWD]

Loved being under a yellow warning for 8mm of rain.

Last few NAE runs weren't showing much in the way of rainfall. Surprised the yellow warning stood so long, although I do think it was right to put it out originally due to what the models were showing a day or two ago.

[Coast]

Latest Sat Rep to decipher where the front is going later today:

[A.J]

quite pleasant here this afternoon.....Broken cloud, some sun, and feeling quite warm in the sun away from the light breeze.....not too shabby!

[Coast]

Things still have a while to get going (if indeed 'get going' is the correct term) the Channel Lightship is reporting a frisky 18.1 kts currently:

http://www.ndbc.noaa.gov/station_page.php?station=62103

[latitude]

Quick glance at the medium to long range potential tonight, <snip>

Lets be honest AWD, its poor outlook for sustained cold. No GH blocking, just a mid atlantic high that topples. Not one of those charts posted show any decent height annomolies, just low pressure continually over Greenland.

The best we can hope for is something like Jan with a weak HP around Iceland maybe towards Scandi.

You really make your forecasts and thoughts very clear. Excellent for people like me who find it hard follow charts,,,,,,,,,,,,,,,,,,,

It is isnt a forecast, its just what the charts show at that time.

Edited February 1, 2013 by shuggee

[Sainsbo]

Well then, January is finally over. 81.6mm of rain for the month here, which is 12% above average. Max temp recorded was 13.5C, and the min temp recorded was -4.6. Average temperatures for the month only slightly below the norm at 4.1C, probably due to the fact that before and after the cold spell we had very mild weather. max gust speed was 40.3mph, and highest 1 min sustained speeds were 24mph.

6.6C here currently, looking forward to what's to come with possibly some colder weather again soon!

[gottolovethisweather]

Further to yesterday's post with regards to the MetO 6-15 dayer, see below for comparison.

http://forum.netweat...40#entry2579824

I will copy below their latest thoughts.

---------------------------------------------------------------------------------------------------------------------------------------------------------

UK Outlook for Wednesday 6 Feb 2013 to Friday 15 Feb 2013:

Conditions tending to remain a little colder than average for much of the period. A fair amount of dry and bright weather across the UK at first, but always the potential for some rain or showers, the showers especially affecting eastern coastal areas, where they could be heavy and thundery with hail and snow. A few wintry showers elsewhere too, particularly Irish Sea coasts and parts of the Midlands at first, but tending to become confined to eastern coasts towards the end of next week. Windy at first, with gales in exposed western areas. Widespread overnight frosts with some icy patches. From the middle of the period, conditions look likely to become a little more unsettled, with temperatures returning to nearer normal, though still perhaps a touch below in places.

Updated: 1210 on Fri 1 Feb 2013

http://www.metoffice...st_weather.html

---------------------------------------------------------------------------------------------------------------------------------------------------------------------

To my mind, this is partly good news and partly bad, depending on which way you read things.

The good news being that for the fourth time in a row, the MetO have made mention of the word SNOW. Clearly, we are to see a return to something cooler with the visiting airmasses having far less of a tropical maritime influence than previously. The result of which being that any activity will contain far less moisture as time ticks on (bear in mind, the timeframe mentioned above ). The bad news if you can call it that, will be that this region will see more in the way of nondescript weather on the whole, being nearer to the HP cell in time. Alongside this, I think the highest chances of any developing snow events will nearly always be in the East.

My assessment above could be construed as slightly negative, however I will say that next week could provide a few of us lucky ones with a brief wintry tease. My main concern is where we go from the 10th February, which is much less clear at this stage.

As ever, Spring proper (at least Astronomically speaking) is yet six to seven weeks away, so plenty of time to play with before throwing the wintry towel in. Furthermore, the first of February's 12z runs are trickling out as I type and will probably produce another spanner in the works for the MetO to think about.

Edited February 1, 2013 by gottolovethisweather