Monday onward, frost, ice returns - snow later

Snowaddict

Apart from the noticeably enhanced signal for precipitation development towards Day 5, as the deep upper cold pool begins to back Westwards towards Ireland, the period between approximately the 16th - 17th of February (Perhaps a day or two either side of this, quite possibly the latter side of these dates), is currently showing a sharply enhanced signal for a potential attempted ''attack'' from the Southwest.

There is no doubt that this will be the eventual outcome as a West Based -NAO develops into the long term, however the area in which low pressure becomes established will be very important. If the general approach is correct, an unsettled Easterly flow could develop for quite some time. Preferably, we would like to see low pressure established in the Med Basin, to prevent an eventual mixing of any Easterly airflow. Elongated troughing some 300-400 miles south would also be a sufficient outcome in such an evolution.

The timing of such an event will depend almost solely upon the exact speed of the Retrogression process. At the moment, it may well be that NWP Guidance is still somewhat too progressive with the overall pattern.

Those considerations aside however, the aforementioned period does show an enhanced signal for a far more cyclonic but still cold to very cold (at least at first) pattern to develop. It is quite possible, even likely in such an evolution, that Ireland will eventually end up on the ''warm'' side of any such trough, but that process itself could well take some time.

This general evolution is indicated on the latest UKMO 15 Day update & the overnight ECMWF T+240 Guidance, so it's something to watch out for on subsequent evolutions.

UKMO 15 Day Outlook

Friday will be cold with brisk northeasterly winds and wintry showers, these more persistent across eastern areas with the risk of significant snow accumulations, mainly in the southeast and East Anglia, possibly central and southern areas as well. Some snow showers likely across Scotland. A frost will form widely, locally sharp in the west and northwest. Saturday will continue cold with further wintry showers, mainly in the southeast, and frosty. The period from Sunday to Tuesday is expected to continue cold with brisk easterly winds. The northwest should be mainly dry, with further wintry showers expected in the southeast. Later in the week there is a risk of some rain, sleet or snow spreading from the south with some significant snowfall possible for a time, but low confidence in detail.

Updated: 1147 on Sun 7 Feb 2010

SA

lucernarian

Thanks once again for that, SA.

[Cautious note]
I still wouldn't call any weather event beyond Wednesday for the moment, as Fantasy Island is called that for a reason and specific details on snow events often can't be pinned down until within 2 days. Widespread snow events to head our way in this marginal part of the world is not an everyday occurrence and things need to happen in a more specific way for it to happen.

In a sentence, we still have all of this week to talk about before becoming too excited at Fantasy Island.
[/cautious note]

Now where is Weathercheck these days? I don't remember seeing a ramp of his recently:P

I also just came across a COAMPS model, it seems to be the more mesoscale equivalent of the NOGAPS model. I spotted it as an option on the Weatheronline charts website. http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en

pauldry

mainly dry days for the coming week with just the frost at night.an odd light wintry shower in the E. as there wont be too much precipitation this is no repeat of the dec/jan big freeze just our normal cold snaps. temps at night of minus 6 would have been fairly impressive in the last 10 winters though!:rolleyes:

Musicman2000

pauldry wrote: »

mainly dry days for the coming week with just the frost at night.an odd light wintry shower in the E. as there wont be too much precipitation this is no repeat of the dec/jan big freeze just our normal cold snaps. temps at night of minus 6 would have been fairly impressive in the last 10 winters though!:rolleyes:

Yeah according to Gerry on Rte, we are not going to see much at all

lol
Technically he's right for a change for the most part this week.
There is a higher probability from thursday onwards but that was conveniently for Gerry outside his range.

Takeshi_Kovacs

While we are waiting with baited breath for 2 cm of sneachta,
Washington DC is experiencing one of the heaviest snowfalls in a long while with 2 feet dumped on the city
http://www.huffingtonpost.com/2010/02/07/dupont-circle-snowball-fi_n_452638.html

Snowaddict

Another relatively consistent 12Z ECMWF Evolution, with indeed a rather more Easterly component to the flow than on previous evolutions, this even beginning at T+72.

There is also a consistent trend towards the Westward advection of a relatively deep cold pool between the latter part of Day 4 through to the latter part of Day 6. As 850mb temperatures approach -9 in Eastern areas for a time, there could well be the increasing risk of snow showers, developing off the Irish Sea.

Further ahead, there remains a consistent signal for Retrogression through Day 5 to Day 7, with Easterly winds persisting, followed by a slack flow for a time. Thereafter, low pressure begins to form to the variable south while an exceptionally deep cold pool is advected across the UK & Ireland from the North & Northeast.

A colder, cyclonic & increasingly unsettled Easterly flow then develops.

In the very long term, it is quite possible that a negative West Based NAO will develop.

Summary

In summary then, a solid 5 Day, increasingly cold spell looks likely. Medium term Guidance beyond Day 5 suggests a continuation of this cold pattern, becoming more cyclonic towards Day 10, as indicated on tonight's NOAA 500mb Height Anomoly Chart:

http://www.cpc.noaa.gov/products/predictions/814day/814day.03.gif

SA

nacho libre

So in a weeks time we may be able to do this: http://www.cnn.com/2010/US/weather/02/07/winter.storm/?hpt=T1

who is up for it?:D

bray man

nacho libre wrote: »

So in a weeks time we may be able to do this: http://www.cnn.com/2010/US/weather/02/07/winter.storm/?hpt=T1

who is up for it?:D

^^ I am but I'm doubtful

Redsunset

NOT RAMPING!!!!!!

BUT,

This is really gonna be a slow burning flame that has the potential to explode with the correct fuel.

Taking in all the trends and signals etc at the moment,
After next weekend (yes i know Fantasy Island)we could see snow in abundance.

I really can't see a whole lot going wrong in the next 7 days,and as Snowaddict also says,heights should have retrogressed and be situated toward eastern canada and greenland to allow cyclonic influence to create havoc.

Combine all this with a now forecasted major warming that should split or severely displace the polar vortex that seems to be now positioned favourably,we can at least be somewhat excited about the prospects that are now realistically possible.

Im very much enjoying this slow build up to a potential timebomb.

A little patience is needed unfortunately,however the rewards could be worth it.

Eyes most firmly on the main models.

pauldry

Yes all this patience and well prob only get a cupla horas schnoooo!

Danno

Here comes the big freeze part 2. Warming has taken place in the arctic and the cold is on it's way to us, it is taking longer than expected to get going but, the siberian express has left the platform and is gonna chugga chugga it's way to Ireland.

Redsunset

LATE WEEK SNOWS LIKELY IN LONDON Okay thaw is over.. time for more fun and games.



I think the heaviest snows of the season are on the way for the southeastern part of Great Britain .


Joe b latest thoughts,

http://www.accuweather.com/ukie/bastardi-europe-blog.asp

DOCARCH

First action of this cold spell now. Light rain shower just turned to a wintery mix of rain, sleet and hail. 3.7c DP 2.3c.

Onwards and upwards!

Supercell

Light graupel shower at Calary driving home today from work. Djouce white above 600 metres or so.

jambofc

is not a bad morning here,no frost and dry 3.5/0.7


M.t. forecast for late in the week and next weekend isn't to promising apart from the south-east on friday

Deep Easterly

Can't say I am overly encouraged by this morning's ECM run. Anticyclone not really shifting east but remaining just to the north of Ireland. It pushes NW later in the run but pushes down a cool polar maritime airflow over Ireland (a consistent theme from this model over the last few runs) which looks to bring cold rain showers rather than widespread snow.

Next!

Agreed.
A rotten looking yoke and a reason for not pinning hopes on FI.
There was an awfull tendency of moving the "good stuff" to a week away in this "spell" anyway-never a good sign.
Looking grand for Eastern England though as usual.

Thats not to say we won't gather up a few light hail sleet and snow showers and it's not to say that the ECM is wrong and that we might get something better.
There have been many runs in the past forthnight that would have given us very different weather today monday than what we actually have.

Rebelbrowser

Just to add my uneducated twopencehal'penny's worth. As stated above many model runs as recently as last Tuesday would have had us basking in 13c or so today. ME/RTE assured us as late as Wednesday night / Thursday morning that we would have a mild south westerly airflow this week. The models do not appear to know what will happen. In relation to Ireland this cold spell (for it is that at least) has almost happened in spite of the models. I remain gormlessly optimistic that most of us will get decent snow between now and Sunday!

As an aside, even the weather we have now and which is likely to be here for the week is being downplayed by ME / RTE. On their forecasts they describe this week as cold but never very/bitterly/perishingly cold. It was 10c yesterday in Cork but the SE wind made it feel nearer freezing. They are forecasting a high of 3c on Friday with a E or NE breeze. That's not going to feel merely "cold" I'd have thought? Has the January big freeze change our definition of cold?

Rebelbrowser

By the way the BBC monthly forecast has just been issued. This proved accurate last week when in the teeth of Model indications to the contrary it said the cold would start today. It doesn't go mad in terms of prediction extreme cold or snow but it suggests for the UK (and NI?) that there's 3 weeks of this ahead. Plenty time then for one decent snow event!

Monday 8 February 2010 to Sunday 14 February 2010
Cold with snow showers in east

The UK will be under the influence of a cold northeasterly airstream. This is the result of an area of high pressure to the north of us and low pressure over Europe. The wind will be quite noticeable at first, gradually easing down during the week but picking up again later on. With temperatures below or well below average (eg. On Wednesday, typically 3/4C) the cooling effect of the wind will be a noteable feature. Overnight frost will become widespread. There should be some sunny spells developing in western areas but for central and eastern areas there will be thicker cloud with showers of rain, sleet and snow. Most of the snow showers will be light, but there is potential for some heavier bursts. The risk of significant accumulations is low for most but the North York Mooors, for example, could see 5 to 10 cm of snow. With the cloudy, showery conditions in the east, sunshine amounts will be somewhat limited, while further west amounts of sunshine should be around normal.

Monday 15 February 2010 to Sunday 21 February 2010
Staying cold

High pressure, centered over the Central Atlantic will keep the cold north to northeasterly airstream across the UK. Weather fronts will try and get into the northwest of the UK, bringing rain, sleet and some hill snow. There will be no let up in the cold feel of things. Temperatures across the UK will stay well below the seasonal norm with overnight frost and some freezing fog. Amounts of precipitation will probably be higher than average in eastern Scotland and the southeast of England while western areas will be relatively dry, especially the northwest of England and Northern Ireland and here there should be a good deal of sunshine. Elsewhere, sunshine amounts are likely to be normal but perhaps rather grey skies will prevail for the northeast of England and Eastern Scotland.

Monday 22 February 2010 to Sunday 7 March 2010
Little change

High pressure continues to feed a cold north or northeasterly airstream across the UK. Minor weather fronts may affect some eastern areas. With the cold airflow, temperatures will remain well below average in all parts. Amounts of precipitation are likely to be well above the norm in northeastern Scotland and the southeast of England with below normal or normal amounts in northwestern and some eastern areas. Confidence in the forecast at this range is moderate, but in terms of the low temperatures, confidence is high.

Rebelbrowser

Rebelbrowser wrote: »

Just to add my uneducated twopencehal'penny's worth. As stated above many model runs as recently as last Tuesday would have had us basking in 13c or so today. ME/RTE assured us as late as Wednesday night / Thursday morning that we would have a mild south westerly airflow this week. The models do not appear to know what will happen. In relation to Ireland this cold spell (for it is that at least) has almost happened in spite of the models. I remain gormlessly optimistic that most of us will get decent snow between now and Sunday!

As an aside, even the weather we have now and which is likely to be here for the week is being downplayed by ME / RTE. On their forecasts they describe this week as cold but never very/bitterly/perishingly cold. It was 10c yesterday in Cork but the SE wind made it feel nearer freezing. They are forecasting a high of 3c on Friday with a E or NE breeze. That's not going to feel merely "cold" I'd have thought? Has the January big freeze change our definition of cold?

Not a hope of much snow really in Ireland whilst that high is positioned as it is.
It might snow a little as the colder surface air seeps in but it won't amount to much.
It's a wait and see after friday.

Sundays country tacks and the uk fax charts will tell a tale come the weekend.

*edit* I might add it's been sleeting lightly here this morning:pac: *edit*

Kippure

MONDAY 3 AM

LATE WEEK SNOWS LIKELY IN LONDON

Okay thaw is over.. time for more fun and games.

The next 5 days will find the upper ridge popping back northwest over Iceland which turns Great Britain into an Iceland. I think the heaviest snows of the season are on the way for the southeastern part of Great Britain ( London) as the deep northeast flow and the very chilly air coming over the water picks up plenty of moisture and the snow flies a new later Thursday into Friday. In any case as we approach Valentines day we find much of Europe in classic cold with the mid and late week maps featuring and icelandic high pressure aloft and plenty of low pressure aloft from Spain to the Balkans and the drainage southwest of cold air back into the west. Make sure you have something, and someone to keep you warm.

ciao for now ****

joe B

London is a long way form Dublin and a lot closer and in fact under the -10 uppers and lower pressure than us.

Mind you-we'll have to wait and see..

WolfeIRE

BBC Monthly outlook has cold weather staying place until the end of the first week of March

Published at 10:00, 8 February
(Next update at 10:00, 15 February)
Written by Jay Wynne

Summary

Cold everywhere with some snow showers

The first week of February saw a bit of a battle going on in the atmosphere, cold air from the near continent butting up against milder air from the Atlantic. The milder air got the upper hand and pushed north across most of the UK with some snow preceding it. It now looks as if the cold air is fighting back - it will be a key feature of the weather over the next few weeks. Average temperatures for early February are in the range of 6C in aberdeen to 8C in London.
Monday 8 February 2010 to Sunday 14 February 2010
Cold with snow showers in east

The UK will be under the influence of a cold northeasterly airstream. This is the result of an area of high pressure to the north of us and low pressure over Europe. The wind will be quite noticeable at first, gradually easing down during the week but picking up again later on. With temperatures below or well below average (eg. On Wednesday, typically 3/4C) the cooling effect of the wind will be a noteable feature. Overnight frost will become widespread. There should be some sunny spells developing in western areas but for central and eastern areas there will be thicker cloud with showers of rain, sleet and snow. Most of the snow showers will be light, but there is potential for some heavier bursts. The risk of significant accumulations is low for most but the North York Mooors, for example, could see 5 to 10 cm of snow. With the cloudy, showery conditions in the east, sunshine amounts will be somewhat limited, while further west amounts of sunshine should be around normal.

Monday 15 February 2010 to Sunday 21 February 2010
Staying cold

High pressure, centered over the Central Atlantic will keep the cold north to northeasterly airstream across the UK. Weather fronts will try and get into the northwest of the UK, bringing rain, sleet and some hill snow. There will be no let up in the cold feel of things. Temperatures across the UK will stay well below the seasonal norm with overnight frost and some freezing fog. Amounts of precipitation will probably be higher than average in eastern Scotland and the southeast of England while western areas will be relatively dry, especially the northwest of England and Northern Ireland and here there should be a good deal of sunshine. Elsewhere, sunshine amounts are likely to be normal but perhaps rather grey skies will prevail for the northeast of England and Eastern Scotland.

Monday 22 February 2010 to Sunday 7 March 2010
Little change

High pressure continues to feed a cold north or northeasterly airstream across the UK. Minor weather fronts may affect some eastern areas. With the cold airflow, temperatures will remain well below average in all parts. Amounts of precipitation are likely to be well above the norm in northeastern Scotland and the southeast of England with below normal or normal amounts in northwestern and some eastern areas. Confidence in the forecast at this range is moderate, but in terms of the low temperatures, confidence is high.

Next week

When will it warm up?

Monthly forecasting

The weather beyond about a week ahead stretches even the most experienced weather forecaster. Complex numerical weather forecast models from the Met Office and the European Centre for Medium Range Weather Forecasting (ECMWF) are run many times for the month (and season) ahead to build up a picture of the likelihood of different weather types affecting the UK.

Tom Cruises Left Nut

Surprise snow would be a lovely thing to get !!

Duiske

Going by the GFS 00z, there is a chance of light wintry showers down the east coast this evening and overnight, These will become confined the south-eastern area's, and gradually die away during the early part of Tuesday.

Beyond that, its pretty much dry with cool days (5 to 7 maxs) cold nights (-3 to -5 mins) for the next week, at least.

Outlooks can and do change, but unless that change is pretty drastic, there is nothing to suggest anything like decent snowfall in the even vaguely reliable future.

228z looks like it has potential for northern areas

Speak Now

Going by the GFS 06z we're looking at a dry and cold for rest of week. The high sitting further south than we'd like and it looks like it may only be an event for south east England. The real cold seems to be getting flooded into central europe. Kinda show's how hard it is for these things to sit right for our little island. Any real snow events are in F1 again. Only positve i could say is that GFS could well be over doing how far south that high will go. Dont see why it should sink so low with such a southerly jet. All in all though it goes to show what an interesting winter we've had weather watching and how lucky we were when things fell right for cold lovers in Dec/Jan. With the atlantic being held at bay so long i hope it doesn't come back to rule the roost like the previous 2 summers

Just had a mixture of everything here drizzle,sleet,light to moderate wet small hail graupel and some snow flakes-a proper "wintry" shower.

2.8/1.1

ninebeanrows

M2 Bouy Dewpoint of 0c.

Some showers possible towards from tonight that could be of snow, unlikely to amount to much but nonetheless would be nice to have a few snow flurries to bring back the memories of the Christmas cold spell.

All in all the whole synoptic isn't too different compared to what we were looking at at the start of the big freeze.

Its a very similar synoptic with a similar retrogression of the high to Greenland forecast.

nacho libre

The longer the cold stays in place the greater the chance of snowfall at some stage. I think it's ill-advised at this juncture to speculate on the first day what will or won't happen, but as a born pessimist i have to say the BBC monthly outlook leaves me hopeful we'll see snow at some point.
Although, we likely won't see significant snowfall from the east or north east so anyone hoping for that should dismiss the idea. Even in the ideal setup it rarely happens when forecast. If we look back at a history of snowfall in ireland the best falls usually caught the forecasters off-guard. Regarding the spring months you can be almost guaranteed once the block is eventually dismantled a lot of our spring will be a wet one as the atlantic roars back into life.